Multiplexed high-throughput immune cell imaging in patients with high-risk triple negative early breast cancer: Analysis from the International Breast Cancer Study Group (IBCSG) Trial 22-00

BACKGROUND

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer (BC) subtype, with dismal prognosis and limited option in advanced settings, yet stromal tumor infiltrating lymphocytes (sTILs) in this subtype has a predictive role.

PATIENTS AND METHODS

The International Breast Cancer Study Group (IBCSG) Trial 22-00 is a randomized phase III clinical trial testing the efficacy of low-dose metronomic oral Cyclophosphamide-Methotrexate (CM) maintenance following standard adjuvant chemotherapy treatment for early-stage hormone receptor-negative breast cancer patients. A case-cohort sampling was used. We characterized immune cells infiltrates in patients with TNBC by 6 plex immunofluorescence (IF) staining for CD4, FOXP3, CD3, cytokeratine and CD8 RESULTS: We confirmed that high immune CD3+ T cells as well as stromal and intra-epithelial Tregs (CD4+Foxp3+ T cells) infiltrates were associated with a better Distant Recurrence-Free Interval (DRFI), especially in LN+ patient, regardless of the treatment. More importantly, we showed that the spatial distribution of immune cells at baseline is crucial, as CM maintenance was detrimental for T cells excluded LN+ TNBC patients.

CONCLUSIONS

immune spatial classification on immune cells infiltrates seems crucial and could help patients' selection in clinical trial and greatly improve responses to specific therapies.

Genomic characterisation of hormone receptor-positive breast cancer arising in very young women

BACKGROUND

Very young premenopausal women diagnosed with hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+HER2-) early breast cancer (EBC) have higher rates of recurrence and death for reasons that remain largely unexplained.

PATIENTS AND METHODS

Genomic sequencing was applied to HR+HER2- tumours from patients enrolled in the Suppression of Ovarian Function Trial (SOFT) to determine genomic drivers that are enriched in young premenopausal women. Genomic alterations were characterised using next-generation sequencing from a subset of 1276 patients (deep targeted sequencing, n = 1258; whole-exome sequencing in a young-age, case-control subsample, n = 82). We defined copy number (CN) subgroups and assessed for features suggestive of homologous recombination deficiency (HRD). Genomic alteration frequencies were compared between young premenopausal women (<40 years) and older premenopausal women (≥40 years), and assessed for associations with distant recurrence-free interval (DRFI) and overall survival (OS).

RESULTS

Younger women (<40 years, n = 359) compared with older women (≥40 years, n = 917) had significantly higher frequencies of mutations in GATA3 (19% versus 16%) and CN amplifications (CNAs) (47% versus 26%), but significantly lower frequencies of mutations in PIK3CA (32% versus 47%), CDH1 (3% versus 9%), and MAP3K1 (7% versus 12%). Additionally, they had significantly higher frequencies of features suggestive of HRD (27% versus 21%) and a higher proportion of PIK3CA mutations with concurrent CNAs (23% versus 11%). Genomic features suggestive of HRD, PIK3CA mutations with CNAs, and CNAs were associated with significantly worse DRFI and OS compared with those without these features. These poor prognostic features were enriched in younger patients: present in 72% of patients aged <35 years, 54% aged 35-39 years, and 40% aged ≥40 years. Poor prognostic features [n = 584 (46%)] versus none [n = 692 (54%)] had an 8-year DRFI of 84% versus 94% and OS of 88% versus 96%. Younger women (<40 years) had the poorest outcomes: 8-year DRFI 74% versus 85% and OS 80% versus 93%, respectively.

CONCLUSION

These results provide insights into genomic alterations that are enriched in young women with HR+HER2- EBC, provide rationale for genomic subgrouping, and highlight priority molecular targets for future clinical trials.

Adjuvant Endocrine Therapy in Premenopausal Breast Cancer: 12-Year Results From SOFT

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The Suppression of Ovarian Function Trial (SOFT; ClinicalTrials.gov identifier: NCT00066690) randomly assigned premenopausal women with hormone receptor-positive breast cancer to 5 years of adjuvant tamoxifen, tamoxifen plus ovarian function suppression (OFS), or exemestane plus OFS. The primary analysis compared disease-free survival (DFS) between tamoxifen plus OFS versus tamoxifen alone; exemestane plus OFS versus tamoxifen was a secondary objective. After 8 years, SOFT reported a significant reduction in recurrence and improved overall survival (OS) with adjuvant tamoxifen plus OFS versus tamoxifen alone. Here, we report outcomes after median follow-up of 12 years. DFS remained significantly improved with tamoxifen plus OFS versus tamoxifen (hazard ratio, 0.82; 95% CI, 0.69 to 0.98) with a 12-year DFS of 71.9% with tamoxifen, 76.1% with tamoxifen plus OFS, and 79.0% with exemestane plus OFS. OS was improved with tamoxifen plus OFS versus tamoxifen (hazard ratio, 0.78; 95% CI, 0.60 to 1.01) and was 86.8% with tamoxifen, 89.0% with tamoxifen plus OFS, and 89.4% with exemestane plus OFS at 12 years. Among those who received prior chemotherapy for human epidermal growth factor receptor-2-negative tumors, OS was 78.8% with tamoxifen, 81.1% with tamoxifen plus OFS, and 84.4% with exemestane plus OFS. In conclusion, after 12 years, there remains a benefit from including OFS in adjuvant endocrine therapy, with an absolute improvement in OS more apparent with higher baseline risk of recurrence.[Media: see text].

Adjuvant Exemestane With Ovarian Suppression in Premenopausal Breast Cancer: Long-Term Follow-Up of the Combined TEXT and SOFT Trials

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The combined analysis of SOFT-TEXT compared outcomes in 4,690 premenopausal women with estrogen/progesterone receptor-positive (ER/PgR+) early breast cancer randomly assigned to 5 years of exemestane + ovarian function suppression (OFS) versus tamoxifen + OFS. After a median follow-up of 9 years, exemestane + OFS significantly improved disease-free survival (DFS) and distant recurrence-free interval (DRFI), but not overall survival, compared with tamoxifen + OFS. We now report DFS, DRFI, and overall survival after a median follow-up of 13 years. In the intention-to-treat (ITT) population, the 12-year DFS (4.6% absolute improvement, hazard ratio [HR], 0.79; 95% CI, 0.70 to 0.90; P < .001) and DRFI (1.8% absolute improvement, HR, 0.83; 95% CI, 0.70 to 0.98; P = .03), but not overall survival (90.1% v 89.1%, HR, 0.93; 95% CI, 0.78 to 1.11), continued to be significantly improved for patients assigned exemestane + OFS over tamoxifen + OFS. Among patients with human epidermal growth factor receptor 2-negative tumors (86.0% of the ITT population), the absolute improvement in 12-year overall survival with exemestane + OFS was 2.0% (HR, 0.85; 95% CI, 0.70 to 1.04) and 3.3% in those who received chemotherapy (45.9% of the ITT population). Overall survival benefit was clinically significant in high-risk patients, eg, women age < 35 years (4.0%) and those with > 2 cm (4.5%) or grade 3 tumors (5.5%). These sustained reductions of the risk of recurrence with adjuvant exemestane + OFS, compared with tamoxifen + OFS, provide guidance for selecting patients for whom exemestane should be preferred over tamoxifen in the setting of OFS.[Media: see text].

Abstract GS2-05: Randomized comparison of adjuvant aromatase inhibitor exemestane (E) plus ovarian function suppression (OFS) vs tamoxifen (T) plus OFS in premenopausal women with hormone receptor-positive (HR+) early breast cancer (BC): update of the combined TEXT and SOFT trials

Background The updated combined SOFT+TEXT analysis, after 9 years median follow-up (MFU), revealed that adjuvant E+OFS vs T+OFS significantly improved disease-free survival (DFS) and distant recurrence-free interval (DRFI) but not overall survival (OS) in premenopausal women with HR+ early BC (Francis et al NEJM 2018). Given the high rate of OS in both arms and the long-term risk of relapse in HR+ BC, continued follow-up is key to assessing treatment benefit. We report a planned update analysis including OS with database lock of May 2021, after 13 years MFU.. Methods TEXT and SOFT enrolled premenopausal women with HR+ early BC from November 2003 to April 2011 (2660 in TEXT, 3047 in SOFT intention-to-treat (ITT) populations). TEXT randomized women within 12 weeks of surgery to 5 years E+OFS vs T+OFS; chemotherapy (CT) was optional and concurrent with OFS. SOFT randomized women to 5 years E+OFS vs T+OFS vs T alone, within 12 weeks of surgery if no CT planned, or within 8 months of completing (neo)adjuvant CT. Both trials were stratified by CT use. For the combined analysis of E+OFS vs T+OFS, the primary endpoint was DFS defined as invasive local, regional, distant recurrence, contralateral BC, second malignancy, death. Secondary endpoints included invasive breast cancer-free interval (BCFI), DRFI and OS.. Results: At database lock there were 953 DFS events and 473 deaths among 4690 pts assigned to T+OFS or E+OFS. In the ITT population, DFS, BCFI and DRFI outcomes for pts assigned E+OFS (n=2346) continued to be significantly improved over T+OFS (n=2344). 12-yr DFS was 80.5% vs. 75.9% (4.6% absolute improvement; HR 0.79 95% CI 0.70-0.90), 12-yr BCFI was improved by 4.1% and 12-yr DRFI by 1.8%. At 12 years OS was excellent in both groups, 90.1% in pts assigned E+OFS vs 89.1% in pts assigned T+OFS (HR 0.93; 95% CI, 0.78-1.11). There was heterogeneity of relative treatment effect according to HER2 status. When enrollment commenced, anti-HER2 adjuvant therapy was not standard; 53% of 583 pts with HER2+ tumors received HER2-targeted therapy. Below are Kaplan-Meier 12-yr estimates for patients with HER2 negative tumors by trial and chemotherapy stratum and for those with high-grade tumours, as an example of high-risk feature (Table). There is an emerging OS benefit for E+OFS vs T+OFS in pts with HER2 negative tumors who received chemotherapy in both trials.In pts with HER2-negative tumors, clinically-relevant outcome benefits were also seen in other high-risk subgroups: 12-yr DFS and OS were improved by 7.4% and 2.7%, respectively, in pts with pN1a disease, and by 10.6% and 4.5%, respectively, in those with tumors &gt;2cm.

Conclusions After 13 years MFU, adjuvant E+OFS, as compared with T+OFS, shows a sustained reduction in the risk of recurrence, more consistent in HER2 negative patients and in those with high-risk disease features, e.g., indication for adjuvant chemotherapy and G3 tumors. Oncologists may use this information to discuss potential benefits of E+OFS with individual patients. Follow-up continues for 5 additional years.

Chemotherapy HER2-negativeSOFTT+OFS (n=424)E+OFS (n=411)Absolute difference12-yr DFS67.4%74.1%6.7%12-yr OS81.1%84.4%3.3%TEXTT+OFS (n=656)E+OFS (n=661)Absolute difference12-yr DFS71.0%78.4%7.4%12-yr OS83.5%86.8%3.3%No chemotherapy HER2-negativeSOFTT+OFS (n=445)E+OFS (n=447)Absolute difference12-yr DFS82.9%88.2%5.3%12-yr OS96.1%96.9%0.9%TEXTT+OFS (n=499)E+OFS (n=492)Absolute difference12-yr DFS80.2%86.7%6.5%12-yr OS95.9%96.2%0.2%G3 HER2-negativeT+OFS (n=423)E+OFS (n=405)Absolute difference12-yr DFS62.7%73.0%10.3%12-yr OS78.1%83.6%5.5%

Citation Format: Meredith M Regan, Barbara A Walley, Gini F Fleming, Prudence A Francis, Marco A Colleoni, István Láng, Henry L Gómez, Carlo A Tondini, Harold J Burstein, Matthew P Goetz, Eva M Ciruelos, Vered Stearns, Hervé R Bonnefoi, Silvana Martino, Charles E Geyer, Jr, Claudio Chini, Alessandro M Minisini, Simon Spazzapan, Thomas Ruhstaller, Eric P Winer, Barbara Ruepp, Sherene Loi, Alan S Coates, Aron Goldhirsch, Richard D Gelber, Olivia Pagani. Randomized comparison of adjuvant aromatase inhibitor exemestane (E) plus ovarian function suppression (OFS) vs tamoxifen (T) plus OFS in premenopausal women with hormone receptor-positive (HR+) early breast cancer (BC): update of the combined TEXT and SOFT trials [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr GS2-05.

Niraparib for Advanced Breast Cancer with Germline BRCA1 and BRCA2 Mutations: the EORTC 1307-BCG/BIG5-13/TESARO PR-30-50-10-C BRAVO Study

PURPOSE

To investigate the activity of niraparib in patients with germline-mutated BRCA1/2 (gBRCAm) advanced breast cancer.

PATIENTS AND METHODS

BRAVO was a randomized, open-label phase III trial. Eligible patients had gBRCAm and HER2-negative advanced breast cancer previously treated with ≤2 prior lines of chemotherapy for advanced breast cancer or had relapsed within 12 months of adjuvant chemotherapy, and were randomized 2:1 between niraparib and physician's choice chemotherapy (PC; monotherapy with eribulin, capecitabine, vinorelbine, or gemcitabine). Patients with hormone receptor-positive tumors had to have received ≥1 line of endocrine therapy and progressed during this treatment in the metastatic setting or relapsed within 1 year of (neo)adjuvant treatment. The primary endpoint was centrally assessed progression-free survival (PFS). Secondary endpoints included overall survival (OS), PFS by local assessment (local-PFS), objective response rate (ORR), and safety.

RESULTS

After the pre-planned interim analysis, recruitment was halted on the basis of futility, noting a high degree of discordance between local and central PFS assessment in the PC arm that resulted in informative censoring. At the final analysis (median follow-up, 19.9 months), median centrally assessed PFS was 4.1 months in the niraparib arm (n = 141) versus 3.1 months in the PC arm [n = 74; hazard ratio (HR), 0.96; 95% confidence interval (CI), 0.65-1.44; P = 0.86]. HRs for OS and local-PFS were 0.95 (95% CI, 0.63-1.42) and 0.65 (95% CI, 0.46-0.93), respectively. ORR was 35% (95% CI, 26-45) with niraparib and 31% (95% CI, 19-46) in the PC arm.

CONCLUSIONS

Informative censoring in the control arm prevented accurate assessment of the trial hypothesis, although there was clear evidence of niraparib's activity in this patient population.

A phase 1, open-label, drug-drug interaction study of rucaparib with rosuvastatin and oral contraceptives in patients with advanced solid tumors

Purpose

This study aimed at evaluating the effect of rucaparib on the pharmacokinetics of rosuvastatin and oral contraceptives in patients with advanced solid tumors and the safety of rucaparib with and without coadministration of rosuvastatin or oral contraceptives.

Methods

Patients received single doses of oral rosuvastatin 20 mg (Arm A) or oral contraceptives ethinylestradiol 30 µg + levonorgestrel 150 µg (Arm B) on days 1 and 19 and continuous doses of rucaparib 600 mg BID from day 5 to 23. Serial blood samples were collected with and without rucaparib for pharmacokinetic analysis.

Results

Thirty-six patients (n = 18 each arm) were enrolled and received at least 1 dose of study drug. In the drug–drug interaction analysis (n = 15 each arm), the geometric mean ratio (GMR) of maximum concentration (C_max) with and without rucaparib was 1.29 for rosuvastatin, 1.09 for ethinylestradiol, and 1.19 for levonorgestrel. GMR of area under the concentration–time curve from time zero to last quantifiable measurement (AUC_0–last) was 1.34 for rosuvastatin, 1.43 for ethinylestradiol, and 1.56 for levonorgestrel. There was no increase in frequency of treatment-emergent adverse events (TEAEs) when rucaparib was given with either of the probe drugs. In both arms, most TEAEs were mild in severity and considered unrelated to study treatment.

Conclusion

Rucaparib 600 mg BID weakly increased the plasma exposure to rosuvastatin or oral contraceptives. Rucaparib safety profile when coadministered with rosuvastatin or oral contraceptives was consistent with that of rucaparib monotherapy. Dose adjustments of rosuvastatin and oral contraceptives are not necessary when coadministered with rucaparib.

ClinicalTrials.gov NCT03954366; Date of registration May 17, 2019.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00280-021-04338-7.

A comparison of eflapegrastim to pegfilgrastim in the management of chemotherapy-induced neutropenia in patients with early-stage breast cancer undergoing cytotoxic chemotherapy (RECOVER): A Phase 3 study

Eflapegrastim (Rolontis^®) is a novel, long‐acting hematopoietic growth factor consisting of a recombinant human granulocyte‐colony stimulating factor (rhG‐CSF) analog conjugated to a human IgG4 Fc fragment via a short polyethylene glycol linker. We report results from a second pivotal, randomized, open‐label, Phase 3 study comparing the efficacy and safety of eflapegrastim to pegfilgrastim for reducing the risk of chemotherapy‐induced neutropenia. Patients with Stage I to IIIA early‐stage breast cancer (ESBC) were randomized 1:1 to fixed‐dose eflapegrastim 13.2 mg (3.6 mg G‐CSF) or pegfilgrastim (6 mg G‐CSF) administered one day after standard docetaxel/cyclophosphamide (TC) therapy for four cycles. The primary objective was to demonstrate noninferiority (NI) of eflapegrastim compared to pegfilgrastim in mean duration of severe neutropenia (DSN; Grade 4) in Cycle 1. A total of 237 eligible patients were randomized 1:1 to receive either eflapegrastim (n = 118) or pegfilgrastim (n = 119). Cycle 1 severe neutropenia was observed in 20.3% (n = 24) of patients receiving eflapegrastim and 23.5% (n = 28) receiving pegfilgrastim. The DSN of eflapegrastim in Cycle 1 was noninferior to pegfilgrastim with a mean difference of −0.074 days (NI P‐value < .0001). Noninferiority was maintained throughout the four treatment cycles (P < .0001 in all cycles). Other efficacy endpoints results were comparable between treatment arms, and adverse events, irrespective of causality and grade, were comparable between treatment arms. The results demonstrate noninferior efficacy and comparable safety for eflapegrastim, at a lower G‐CSF dose, vs pegfilgrastim. The potential for the increased potency of eflapegrastim to deliver improved clinical benefit warrants further clinical study.

Long-term cardiac outcomes of patients with HER2-positive breast cancer treated in the adjuvant lapatinib and/or trastuzumab Treatment Optimization Trial

BACKGROUND

Cardiotoxicity is the most significant adverse event associated with trastuzumab (T), the main component of HER2-positive breast cancer (BC) treatment. Less is known about the cardiotoxicity of dual HER2 blockade with T plus lapatinib (L), although this regimen is used in the metastatic setting.

METHODS

This is a sub-analysis of the ALTTO trial comparing adjuvant treatment options for patients with early HER2-positive BC. Patients randomised to either T or concomitant T + L were eligible. Cardiac events (CEs) rates were compared according to treatment arm.

RESULTS

With 6.9 years of median follow-up (FU) and 4190 patients, CE were observed in 363 (8.6%): 166 (7.9%) of patient in T + L arm vs. 197 (9.3%) in T arm (OR = 0.85 [95% CI, 0.68-1.05]). During anti-HER2 treatment 270 CE (6.4%) occurred while 93 (2.2%) were during FU (median time to onset = 6.6 months [IQR = 3.4-11.7]). While 265 CEs were asymptomatic (73%), 94 were symptomatic (26%) and four were cardiac deaths (1%). Recovery was observed in 301 cases (83.8%). Identified cardiac risk factors were: baseline LVEF < 55% (vs > 64%, OR 3.1 [95% CI 1.54-6.25]), diabetes mellitus (OR 1.85 [95% CI 1.25-2.75]), BMI > 30 kg/m2 (vs < 25 mg/kg2, OR 2.21 [95% CI 1.40-3.49]), cumulative dose of doxorubicin ≥240 mg/m2 (OR 1.36 [95% CI 1.01-1.82]) and of epirubicin≥ 480 mg/m2 (OR 2.33 [95% CI 1.55-3.51]).

CONCLUSIONS

Dual HER2 blockade with T + L is a safe regimen from a cardiac perspective, but cardiac-focused history for proper patient selection is crucial.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT00490139 (registration date: 22/06/2007); EudraCT Number: 2006-000562-36 (registration date: 04/05/2007); Sponsor Protocol Number: BIG2-06 /EGF106708/N063D.

Absolute Improvements in Freedom From Distant Recurrence to Tailor Adjuvant Endocrine Therapies for Premenopausal Women: Results From TEXT and SOFT

PURPOSE

The Tamoxifen and Exemestane Trial (TEXT)/Suppression of Ovarian Function Trial (SOFT) showed superior outcomes for premenopausal women with hormone receptor (HR)-positive breast cancer treated with adjuvant exemestane plus ovarian function suppression (OFS) or tamoxifen plus OFS versus tamoxifen alone. We previously reported the magnitude of absolute improvements in freedom from any recurrence across a continuous, composite measure of recurrence risk to tailor decision making. With longer follow-up, we now focus on distant recurrence.

METHODS

The TEXT/SOFT HR-positive/human epidermal growth factor receptor 2 (HER2)-negative analysis population included 4,891 women stratified by predetermined chemotherapy use. Kaplan-Meier estimates of 8-year freedom from distant recurrence were analyzed using subpopulation treatment effect pattern plot (STEPP) methodology across subpopulations defined by the continuous composite measure of recurrence risk. For each patient, the composite risk value was obtained from a Cox model that incorporated age; nodal status; tumor size; grade; and estrogen receptor, progesterone receptor, and Ki-67 labeling index expression levels.

RESULTS

The overall rate of 8-year freedom from distant recurrence was 91.1% and ranged from approximately 100% to 63% across lowest to highest composite risks. TEXT patients who received chemotherapy had an average absolute improvement with exemestane plus OFS versus tamoxifen plus OFS of 5.1%, and STEPP analysis showed improvements from less than 1% to more than 15% from lowest to highest composite risks. SOFT patients who remained premenopausal after chemotherapy had an average 5.2% absolute improvement with exemestane plus OFS versus tamoxifen and reached 10% across composite risks; for tamoxifen plus OFS versus tamoxifen, the maximum improvement was approximately 3.5%. Women who did not receive chemotherapy had a more than 97% rate of 8-year freedom from distant recurrence, and improvements with exemestane plus OFS ranged from 1% to 4%.

CONCLUSION

Premenopausal women with HR-positive/HER2-negative breast cancer and high recurrence risk, as defined by clinicopathologic characteristics, may experience a 10% to 15% absolute improvement in 8-year freedom from distant recurrence with exemestane plus OFS versus tamoxifen plus OFS or tamoxifen alone. The potential benefit of escalating endocrine therapy versus tamoxifen alone is minimal for those at low recurrence risk.

Evaluation of the effect of P-glycoprotein inhibition and induction on talazoparib disposition in patients with advanced solid tumours

Aims

In vitro data show that talazoparib is a substrate for P‐glycoprotein (P‐gp) and breast cancer resistance protein transporters. This open‐label, 2‐arm, drug–drug interaction Phase 1 study in patients with advanced solid tumours assessed the effect of a P‐gp inhibitor (itraconazole) and a P‐gp inducer (rifampicin) on the pharmacokinetics of a single dose of talazoparib. The safety and tolerability of a single dose of talazoparib with and without itraconazole or rifampicin were also assessed.

Methods

Thirty‐six patients were enrolled (Arm A [itraconazole], n = 19; Arm B [rifampicin], n = 17). Patients in both arms received 2 single oral doses of talazoparib (0.5 mg, Arm A; 1 mg, Arm B) alone and with multiple daily oral doses of itraconazole (Arm A) or rifampicin (Arm B).

Results

Coadministration of itraconazole and talazoparib increased talazoparib area under the plasma concentration–time profile from time 0 extrapolated to infinity by ~56% and maximum observed plasma concentration by ~40% relative to talazoparib alone. Coadministration of rifampicin and talazoparib increased talazoparib maximum observed plasma concentration by approximately 37% (geometric mean ratio 136.6% [90% confidence interval 103.2–180.9]); area under the curve was not affected relative to talazoparib alone (geometric mean ratio 102.0% [90% confidence interval 94.0–110.7]). Talazoparib had an overall safety profile consistent with that observed in prior studies in which talazoparib was administered as a single dose.

Conclusion

Coadministration of itraconazole increased talazoparib plasma exposure compared to talazoparib alone. A reduced talazoparib dose is recommended if coadministration of potent P‐gp inhibitors cannot be avoided. Similar exposure was observed when talazoparib was administered alone and with rifampicin suggesting that the effect of rifampicin on talazoparib exposure is limited.

Randomized phase 3 efficacy and safety trial of proposed pegfilgrastim biosimilar MYL-1401H in the prophylactic treatment of chemotherapy-induced neutropenia

Pegfilgrastim is indicated for reducing the duration of neutropenia and incidence of febrile neutropenia in patients receiving cytotoxic chemotherapy. Here, safety and efficacy of MYL-1401H, a proposed pegfilgrastim biosimilar, were investigated as prophylaxis for chemotherapy-induced neutropenia. This was a phase 3, multicenter, randomized, double-blind, parallel-group equivalence trial of MYL-1401H vs European Union–sourced reference pegfilgrastim. Patients with newly diagnosed stage II/III breast cancer eligible to receive (neo) adjuvant chemotherapy with docetaxel/doxorubicin/cyclophosphamide every 3 weeks for 6 cycles were enrolled and randomized 2:1 to 6 mg of MYL-1401H or reference pegfilgrastim 24 h (+ 2-h window after the first 24 h) after the end of chemotherapy. The primary efficacy endpoint was the duration of severe neutropenia in cycle 1 (i.e., days with absolute neutrophil count (ANC) < 0.5 × 10⁹/L). Mean (standard deviation (SD)) duration of severe neutropenia in MYL-1401H and reference pegfilgrastim groups was 1.2 days (0.93) and 1.2 days (1.10), respectively. The 95% CI for least squares mean difference (− 0.285, 0.298) was within the predefined equivalence range of ± 1 day. Secondary endpoints, including grade ≥ 3 neutropenia (frequency, 91% and 82% for MYL-1401H and reference pegfilgrastim, respectively), time to ANC nadir (mean (SD), 6.2 (0.98) and 6.3 (1.57) days), and duration of post-nadir recovery (mean (SD), 1.9 (0.85) and 1.7 (0.91) days) were comparable. Overall safety profiles of the study drugs were comparable. MYL-1401H demonstrated equivalent efficacy and similar safety to reference pegfilgrastim and may be an equivalent option for reducing incidence of neutropenia. (ClinicalTrials.gov, NCT02467868; EudraCT, 2014-002324-27).

Abstract P2-13-03: The impact of neratinib with or without anti-diarrheal prophylaxis on health-related quality of life in HER2+ early-stage breast cancer: Analyses from the ExteNET and CONTROL trials

Background: Neratinib is an irreversible pan-HER tyrosine kinase inhibitor. ExteNET, a randomized placebo-controlled phase III study, showed that neratinib given for 12 months after trastuzumab-based adjuvant therapy significantly improved 2-year (HR 0.67; 95% CI 0.50–0.91; p=0.0091) and 5-year (HR 0.73; 95% CI 0.57-0.92; p=0.008) iDFS in pts with early-stage HER2+ breast cancer. Anti-diarrheal prophylaxis was not mandated by protocol; grade 3/4 diarrhea occurred in 40% of pts with a median cumulative duration of 5 days. The phase II CONTROL study was initiated to investigate the effectiveness of various prophylactic regimens in the prevention of neratinib-associated diarrhea. Loperamide (L) alone or in combination with add-on agents targeting underlying inflammation [i.e. budesonide (BUD)] or bile acid malabsorption [i.e. colestipol (COL)] were tested. We report longitudinal HRQoL findings from both ExteNET and CONTROL.

Methods: Pts with early-stage HER2+ breast cancer who had received trastuzumab-based adjuvant therapy were eligible for both studies. In ExteNET, pts received neratinib or placebo for 12 months. In CONTROL, pts received neratinib for 13 x 28-day cycles combined with L, L + BUD or L + COL for 1 or 2 cycles (see table for schedules). HRQoL was assessed using Functional Assessment of Cancer Therapy–Breast (FACT-B), v4.0, at baseline, months 1, 3, 6, 9, 12 (ExteNET) or baseline, cycles 2, 4, 7, 10, 13 (CONTROL). Changes in scores from baseline were considered to be clinically meaningful if greater than the lowest estimate for an 'important difference' (ID) reported in the literature. Evaluable pts were required to have HRQoL assessments at baseline and at least 1 post-baseline. ClinicalTrials.gov: NCT00878709 (ExteNET); NCT02400476 (CONTROL).

Results: HRQoL findings are summarized in the table. Hospitalization rates due to diarrhea: 1.5% (neratinib + L), 0% (other cohorts) in CONTROL; and 1.4% (neratinib), 0.1% (placebo) in ExteNET.

  Mean change from baselineStudyCohort/GroupM1M3M6M9M12 FACT-B TOTAL (ID range: 7–8 points)CONTROLN + La,b (N=40)–3.8–4.5–1.5–2.5–3.3 N + L + BUDa,b,c (N=62)–6.0–4.9–1.6–3.6–4.5 N + L + COLa,b,d (N=125)–3.8–2.0–4.0–4.6–3.6 N + L prn + COLa,d (N=85)–1.8–1.54.0e––ExteNETN + L prna (N=1124)–4.6–3.4–3.5–3.3–3.7 P (N=1188)–1.7–3.5–2.9–2.9–2.8 FACT-B PWB (ID range: 2–3 points)CONTROLN + La,b (N=40)–4.0–2.3–1.9–2.4–2.3 N + L + BUDa,b,c (N=62)–3.2–2.1–1.4–1.7–1.7 N + L + COLa,b,d (N=125)–2.8–2.0–2.4–2.5–2.4 N + L prn + COLa,d (N=85)–2.8–1.80.0e––ExteNETN + L prna (N=1124)–2.9–1.9–1.7–1.6–1.5 P (N=1188)–0.6–0.8–0.7–0.6–0.4C, cycle; L, loperamide; M, month; N, neratinib; prn, as needed; PWB, physical well-being. CONTROL cut-off: 1 May 2018. aN 240 mg qd for 13 x 28d cycles or 12 months; bL 4 mg, then 4 mg tid d1-14, then 4 mg bid d15-28 or d15-56, then prn; cBUD 9 mg qd d1-28; dCOL 2 g qd d1-28; en=1.

Conclusions: Adjuvant neratinib with or without anti-diarrheal prophylaxis was associated with small decreases in HRQoL. With the exception of the FACT-B PWB subscale, HRQoL changes did not reach clinically meaningful thresholds. Follow-up in CONTROL is ongoing.

Citation Format: Delaloge S, Hurvitz S, Chan N, Bose R, Jankowitz RC, Thirlwell M, Láng I, ten Tije A, Trudeau M, Osborne CR, Shen Z-Z, Lalla D, Xu F, Hunt D, Olek E, Tripathy D, Rugo HS, Chien J, Chan A, Barcenas CH. The impact of neratinib with or without anti-diarrheal prophylaxis on health-related quality of life in HER2+ early-stage breast cancer: Analyses from the ExteNET and CONTROL trials [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-13-03.

Abstract P4-14-01: Estrogen levels in premenopausal patients (pts) with hormone-receptor positive (HR+) early breast cancer (BC) receiving adjuvant triptorelin (Trip) plus exemestane (E) or tamoxifen (T) in the SOFT trial: SOFT-EST substudy final analysis

Background: Optimal endocrine therapy for premenopausal pts with early HR+ BC may depend on complete estrogen suppression with GnRH analog, which is crucial when using concurrent aromatase inhibitors (AIs). SOFT-EST is a prospective substudy of the phase 3 SOFT trial aiming to describe estradiol (E2), estrone (E1) and estrone sulphate (E1S) during the first 4 years (y) of monthly Trip+E/T and to assess if there were suboptimally estrogen suppressed (SES) pts in the E+Trip group. Secondary objectives included associations of baseline (BL) factors with SES, early SES with later SES, and SES with disease-free survival (DFS; exploratory objective).

Methods: Patients from select centers who consented and enrolled in SOFT, selected Trip as ovarian function suppression method, and were randomized to E+Trip or T+Trip were eligible for SOFT-EST until the accrual goal (120 pts: 90 E+Trip; 30 T+Trip). Prem status for SOFT eligibility was based on local E2. Blood sampling timepoints were 0, 3, 6, 12, 18, 24, 36 & 48 months (m) until Trip stopped. Serum estrogens were measured centrally by high specificity/sensitivity GC/MSMS and were not available during the study. For 4y analyses, SES was defined as E2 levels &gt;2.72 pg/mL in ≥2 post-BL samples (E2 levels not consistent with postmenopausal (PM) status on AIs [Smith IE, JCO 2006]), or vaginal bleeding &gt;3m after Trip start, or pregnancy. We explored 2 additional cutoffs: &gt;10 pg/mL (clearly inconsistent with PM status on AIs) and &gt;20 pg/mL (inconsistent with GnRH analog-related PM status). The analysis is intention-to-treat based on E/T assignment; as-treated analyses are forthcoming.

Results: From Mar 2009 to Jan 2011,109 pts (E/T=83/26) started Trip and had ≥2 samples drawn. In pts assigned E+Trip, median reductions from BL in E1, E2 and E1S were &gt;95% at all timepoints and significantly lower than in T+Trip. Post-BL E2 geometric mean ranged 0.8-1.3 pg/mL in E+Trip and 16.5-18.3 pg/mL in T+Trip. 21 (25%), 11 (13%) and 6 (7%) pts assigned to E+Trip had E2&gt;2.72, &gt;10, and &gt;20 pg/mL in ≥2 post BL samples or vaginal bleeding (n=3), respectively. Early SES [(≥1 E2 value &gt;2.72 pg/mL or vaginal bleeding in the firsty] predicted later SES [≥1 E2 value &gt;2.72 or vaginal bleeding thereafter (n=1); p&lt;0.001]. BL factors related to SES were higher E2, lower FSH and lower LH values (p=0.02, p&lt;0.01, p&lt;0.01 respectively). 12m FSH levels were not related to SES. In pts assigned E+Trip, after 6y median follow-up, DFS events were seen in 0 of 21 pts with SES vs 5 of 62 pts without SES.

Conclusions: Most pts on E+Trip had a profound E2 drop consistent with postmenopausal status on AI, but &gt;20% assigned to E+Trip had ≥2 E2 values &gt;2.72 pg/mL and 4% had vaginal bleeding, with those having higher E2, lower FSH/LH at BL being at higher risk. SES at 12m predicted subsequent SES. Few DFS events limit the ability to assess clinical relevance of SES with disease outcomes.

BL characteristicsN-109Prior chemo60 (55%)Amenorrhea39 (36%)Age &lt;35y8 (7%) Median (range)Age, y44 (25-53)BMI, kg/m224 (22-28)Estrogen (pg/mL) E252 (7-119)E141 (24-70)E1S894 (304-1320)FSH/LH (IU/L) FSH15 (7-47)LH11 (6-26)

Citation Format: Bellet M, Gray K, Francis P, Láng I, Ciruelos E, Lluch A, Ángel Climent M, Catalán G, Avella A, Bohn U, González-Martin A, Zaman K, Ferrer R, Azaro A, Rajasekaran A, De la Peña L, Fleming G, Regan MM. Estrogen levels in premenopausal patients (pts) with hormone-receptor positive (HR+) early breast cancer (BC) receiving adjuvant triptorelin (Trip) plus exemestane (E) or tamoxifen (T) in the SOFT trial: SOFT-EST substudy final analysis [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-14-01.

Adjuvant Letrozole and Tamoxifen Alone or Sequentially for Postmenopausal Women With Hormone Receptor-Positive Breast Cancer: Long-Term Follow-Up of the BIG 1-98 Trial

PURPOSE

Luminal breast cancer has a long natural history, with recurrences continuing beyond 10 years after diagnosis. We analyzed long-term follow-up (LTFU) of efficacy outcomes and adverse events in the Breast International Group (BIG) 1-98 study reported after a median follow-up of 12.6 years.

PATIENTS AND METHODS

BIG 1-98 is a four-arm, phase III, double-blind, randomized trial comparing adjuvant letrozole versus tamoxifen (either treatment received for 5 years) and their sequences (2 years of one treatment plus 3 years of the other) for postmenopausal women with endocrine-responsive early breast cancer. When pharmaceutical company sponsorship ended at 8.4 years of median follow-up, academic partners initiated an observational, LTFU extension collecting annual data on survival, disease status, and adverse events. Information from Denmark was from the Danish Breast Cancer Cooperative Group Registry. Intention-to-treat analyses are reported.

RESULTS

Of 8,010 enrolled patients, 4,433 were alive and not withdrawn at an LTFU participating center, and 3,833 (86%) had at least one LTFU report. For the monotherapy comparison of letrozole versus tamoxifen, we found a 9% relative reduction in the hazard of a disease-free survival event with letrozole (hazard ratio [HR], 0.91; 95% CI, 0.81 to 1.01). HRs for other efficacy end points were similar to those for disease-free survival. Efficacy of letrozole versus tamoxifen for contralateral breast cancer varied significantly over time (0- to 5-, 5- to 10-, and > 10-year HRs, 0.62, 0.47, and 1.35, respectively; treatment-by-time interaction P = .005), perhaps reflecting a longer carryover effect of tamoxifen. Reporting of specific long-term adverse events seemed more effective with national registry than with case-record reporting of clinical follow-up.

CONCLUSION

Efficacy end points continued to show trends favoring letrozole. Letrozole reduced contralateral breast cancer frequency in the first 10 years, but this reversed beyond 10 years. This study illustrates the value of extended follow-up in trials of luminal breast cancer.

Tailoring Adjuvant Endocrine Therapy for Premenopausal Breast Cancer

BACKGROUND

In the Suppression of Ovarian Function Trial (SOFT) and the Tamoxifen and Exemestane Trial (TEXT), the 5-year rates of recurrence of breast cancer were significantly lower among premenopausal women who received the aromatase inhibitor exemestane plus ovarian suppression than among those who received tamoxifen plus ovarian suppression. The addition of ovarian suppression to tamoxifen did not result in significantly lower recurrence rates than those with tamoxifen alone. Here, we report the updated results from the two trials.

METHODS

Premenopausal women were randomly assigned to receive 5 years of tamoxifen, tamoxifen plus ovarian suppression, or exemestane plus ovarian suppression in SOFT and to receive tamoxifen plus ovarian suppression or exemestane plus ovarian suppression in TEXT. Randomization was stratified according to the receipt of chemotherapy.

RESULTS

In SOFT, the 8-year disease-free survival rate was 78.9% with tamoxifen alone, 83.2% with tamoxifen plus ovarian suppression, and 85.9% with exemestane plus ovarian suppression (P=0.009 for tamoxifen alone vs. tamoxifen plus ovarian suppression). The 8-year rate of overall survival was 91.5% with tamoxifen alone, 93.3% with tamoxifen plus ovarian suppression, and 92.1% with exemestane plus ovarian suppression (P=0.01 for tamoxifen alone vs. tamoxifen plus ovarian suppression); among the women who remained premenopausal after chemotherapy, the rates were 85.1%, 89.4%, and 87.2%, respectively. Among the women with cancers that were negative for HER2 who received chemotherapy, the 8-year rate of distant recurrence with exemestane plus ovarian suppression was lower than the rate with tamoxifen plus ovarian suppression (by 7.0 percentage points in SOFT and by 5.0 percentage points in TEXT). Grade 3 or higher adverse events were reported in 24.6% of the tamoxifen-alone group, 31.0% of the tamoxifen-ovarian suppression group, and 32.3% of the exemestane-ovarian suppression group.

CONCLUSIONS

Among premenopausal women with breast cancer, the addition of ovarian suppression to tamoxifen resulted in significantly higher 8-year rates of both disease-free and overall survival than tamoxifen alone. The use of exemestane plus ovarian suppression resulted in even higher rates of freedom from recurrence. The frequency of adverse events was higher in the two groups that received ovarian suppression than in the tamoxifen-alone group. (Funded by Pfizer and others; SOFT and TEXT ClinicalTrials.gov numbers, NCT00066690 and NCT00066703 , respectively.).

Efficacy of Chemotherapy for ER-Negative and ER-Positive Isolated Locoregional Recurrence of Breast Cancer: Final Analysis of the CALOR Trial

Purpose Isolated locoregional recurrence (ILRR) predicts a high risk of developing breast cancer distant metastases and death. The Chemotherapy as Adjuvant for LOcally Recurrent breast cancer (CALOR) trial investigated the effectiveness of chemotherapy (CT) after local therapy for ILRR. A report at 5 years of median follow-up showed significant benefit of CT for estrogen receptor (ER)-negative ILRR, but additional follow-up was required in ER-positive ILRR. Patients and Methods CALOR was an open-label, randomized trial for patients with completely excised ILRR after unilateral breast cancer. Eligible patients were randomly assigned to receive CT or no CT and stratified by prior CT, hormone receptor status, and location of ILRR. Patients with hormone receptor-positive ILRR received adjuvant endocrine therapy. Radiation therapy was mandated for patients with microscopically involved margins, and anti-human epidermal growth factor receptor 2 therapy was optional. End points were disease-free survival (DFS), overall survival, and breast cancer-free interval. Results From August 2003 to January 2010, 162 patients were enrolled: 58 with ER-negative and 104 with ER-positive ILRR. At 9 years of median follow-up, 27 DFS events were observed in the ER-negative group and 40 in the ER-positive group. The hazard ratios (HR) of a DFS event were 0.29 (95% CI, 0.13 to 0.67; 10-year DFS, 70% v 34%, CT v no CT, respectively) in patients with ER-negative ILRR and 1.07 (95% CI, 0.57 to 2.00; 10-year DFS, 50% v 59%, respectively) in patients with ER-positive ILRR ( Pinteraction = .013). HRs were 0.29 (95% CI, 0.13 to 0.67) and 0.94 (95% CI, 0.47 to 1.85), respectively, for breast cancer-free interval ( Pinteraction = .034) and 0.48 (95% CI, 0.19 to 1.20) and 0.70 (95% CI, 0.32 to 1.55), respectively, for overall survival ( Pinteraction = .53). Results for the three end points were consistent in multivariable analyses adjusting for location of ILRR, prior CT, and interval from primary surgery. Conclusion The final analysis of CALOR confirms that CT benefits patients with resected ER-negative ILRR and does not support the use of CT for ER-positive ILRR.

Mutational analysis of triple-negative breast cancers within the International Breast Cancer Study Group (IBCSG) Trial 22-00

PURPOSE

We investigated the occurrence and the prognostic and predictive relationship of a selected number of somatic mutations in triple-negative breast cancer (TNBC) patients having known clinical outcomes treated within the IBCSG Trial 22-00.

METHODS

A matched case-control sampling selected patients enrolled in the IBCSG Trial 22-00 who had TNBC tumors, based on local assessment. Cases had invasive breast cancer recurrence (at local, regional, or distant site) according to the protocol definition. Matched controls had not recurred. Mutational analysis was performed with OncoCarta panel v1.0 using Mass Array System. The panel includes 19 genes belonging to different functional pathways as PI3K pathway, receptor tyrosine kinase, and cell cycle-metabolic group. Conditional logistic regression assessed the association of mutation status with breast cancer recurrence.

RESULTS

Mutation assessment was successful for 135 patients (49 cases, 86 controls). A total of 37 (27.4%) of the 135 patients had at least one mutation in the selected genes. PIK3CA was the most common mutated gene (18/135; 13.3%), followed by BRAF, KIT and PDGFRA (each 4/135, 3.0%) and AKT1 (3/135; 2.2%). TNBC patients with at least one mutation had increased odds of recurrence compared with those with wild-type tumors (odds ratio (OR) 2.28; 95% CI 0.88-5.92), though this difference was not statistically significant (p = 0.09). We found no evidence that these mutations were predictive for the value of maintenance metronomic chemotherapy.

CONCLUSIONS

Mutations in the tested oncogenes were not associated with breast cancer recurrence in this TNBC subset of patients. The question of whether any of these mutated genes (e.g., PIK3CA) may represent a useful therapeutic target in TNBC may be answered by ongoing clinical trials and/or larger dataset analysis.

An open-label, dose-ranging study of Rolontis, a novel long-acting myeloid growth factor, in breast cancer

This randomized, open‐label, active‐controlled study investigated the safety and efficacy of three doses of Rolontis (eflapegrastim), a novel, long‐acting myeloid growth factor, versus pegfilgrastim in breast cancer patients being treated with docetaxel and cyclophosphamide (TC). The primary efficacy endpoint was duration of severe neutropenia (DSN) during the first cycle of treatment. Patients who were candidates for adjuvant/neoadjuvant TC chemotherapy were eligible for participation. TC was administered on Day 1, followed by 45, 135, or 270 μg/kg Rolontis or 6 mg pegfilgrastim on Day 2. Complete blood counts were monitored daily when the absolute neutrophil count (ANC) fell to <1.5 × 10⁹/L. Up to four cycles of TC were investigated. The difference in DSN (time from ANC <0.5 × 10⁹/L to ANC recovery ≥2.0 × 10⁹/L) between the Rolontis and pegfilgrastim groups was −0.28 days (confidence interval [CI]: −0.56, −0.06) at 270 μg/kg, 0.14 days (CI: −0.28, 0.64) at 135 μg/kg, and 0.72 days (CI: 0.19, 1.27) at 45 μg/kg. Noninferiority to pegfilgrastim was demonstrated at 135 μg/kg (P = 0.002) and 270 μg/kg (P < .001), with superiority demonstrated at 270 μg/kg (0.03 days; P = 0.023). The most common treatment‐related adverse events (AEs) were bone pain, myalgia, arthralgia, back pain, and elevated white blood cell counts, with similar incidences across groups. All doses of Rolontis were well tolerated, and no new or significant treatment‐related toxicities were observed. In Cycle 1, Rolontis demonstrated noninferiority at the 135 μg/kg dose and statistical superiority in DSN at the 270 μg/kg dose when compared to pegfilgrastim.

Abstract GS4-02: Randomized comparison of adjuvant aromatase inhibitor exemestane (E) plus ovarian function suppression (OFS) vs tamoxifen (T) plus OFS in premenopausal women with hormone receptor positive (HR+) early breast cancer (BC): Update of the combined TEXT and SOFT trials

Background: The combined results of TEXT and SOFT, after 5.7 years median follow-up, found adjuvant E+OFS significantly improved disease-free survival (DFS) vs T+OFS in premenopausal women with HR+ BC (Pagani et al, NEJM 2014). Follow-up was immature for overall survival (OS). We report a planned update with visit cut-off of 31Dec16 after 9 years median follow-up.

Methods: TEXT and SOFT enrolled premenopausal women with HR+ early BC from Nov 2003 to Apr 2011 (2660 TEXT, 3047 SOFT in the intention-to-treat populations). TEXT randomized women within 12wk of surgery to 5 yrs E+OFS vs T+OFS; chemotherapy (CT) was optional and concurrent with OFS. SOFT randomized women to 5 yrs E+OFS vs T+OFS vs T alone, within 12wk of surgery if no CT planned, or within 8mo of completing (neo)adjuvant CT after premenopausal status was (re-)established. OFS was by choice of 5yr GnRH agonist triptorelin, oophorectomy or ovarian irradiation. Both trials were stratified by CT use. The primary endpoint was DFS: randomization until invasive local, regional, distant recurrence or contralateral breast; invasive second malignancy; death. Secondary endpoints included invasive breast cancer-free interval (BCFI), distant recurrence-free interval (DRFI) and OS. Stratified Cox models estimated hazard ratios; Kaplan-Meier method estimated 8yr endpoint rates. NCT00066703/NCT00066690.

Results: DFS for patients assigned E+OFS (n=2346) continued to be significantly improved over T+OFS (n=2344): 8yr DFS was 86.8% vs. 82.8%. The 8yr BCFI was improved by 4.1% (89.3% vs 85.2%) and 8yr DRFI by 2.1% (91.8% vs 89.7%). There was no difference in OS in patients assigned E+OFS vs T+OFS: 93.4% vs 93.3% OS at 8yrs. For 1996 women without CT there have been 45 deaths, with 98% OS at 8yrs with both treatments.

EndpointN. EventsHazard Ratio (95% CI) E+OFS vs T+OFSDFS7200.77 (0.67-0.90); P&lt;0.001BCFI6000.74 (0.63-0.87)DRFI4330.80 (0.65-0.96)OS3200.98 (0.79-1.22)

Overall toxicity was not significantly worse with E+OFS than with T+OFS (32% vs 31% grade 3-4 targeted AEs). Hot flashes, musculoskeletal symptoms and hypertension were the most frequent targeted grade 3-4 AEs. Overall, 15% of patients stopped all protocol-assigned treatment early. Patients assigned E+OFS had increased risk of assigned oral endocrine therapy cessation (25% vs 19% for patients assigned T+OFS by 4yrs) but not of triptorelin cessation (18% vs 19% by 4yrs, respectively).

Conclusions: After 9 yrs median follow-up, adjuvant E+OFS, as compared with T+OFS, shows a sustained reduction of the risk of recurrence but did not improve overall survival. As in postmenopausal women, oncologists need to consider potential absolute benefits and properly select patients at sufficient risk for recurrence for whom E+OFS seems indicated. Follow-up continues, which will further clarify the effect of E+OFS for safety, late recurrence and overall survival.

Citation Format: Pagani O, Regan MM, Fleming GF, Walley BA, Colleoni M, Láng I, Gomez HL, Tondini C, Burstein HJ, Goetz MP, Ciruelos EM, Stearns V, Debled M, Martino S, Geyer Jr CE, Pinotti G, Coates AS, Goldhirsch A, Gelber RD, Francis PA. Randomized comparison of adjuvant aromatase inhibitor exemestane (E) plus ovarian function suppression (OFS) vs tamoxifen (T) plus OFS in premenopausal women with hormone receptor positive (HR+) early breast cancer (BC): Update of the combined TEXT and SOFT trials [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr GS4-02.

Abstract GS4-03: Randomized comparison of adjuvant tamoxifen (T) plus ovarian function suppression (OFS) versus tamoxifen in premenopausal women with hormone receptor-positive (HR+) early breast cancer (BC): Update of the SOFT trial

Background: The primary results of SOFT at 5.6 years median follow-up found adding OFS to T did not provide a significant benefit in the overall study population of premenopausal women with HR+ BC (Francis et al, NEJM 2015). For those women at sufficient risk for recurrence to warrant adjuvant chemotherapy (CT) and who remained premenopausal, the addition of OFS improved disease outcomes. Follow-up was immature for overall survival (OS). We report a planned update with visit cut-off of 31Dec16 after 8 yrs median follow-up.

Methods: SOFT randomized premenopausal women with HR+ BC from Nov 2003 to Jan 2011 to 5 yrs of T vs T+OFS vs Exemestane(E)+OFS. OFS was by choice of GnRH agonist triptorelin, oophorectomy or ovarian irradiation. SOFT was stratified by the use of prior CT; 47% received no CT and 53% remained premenopausal after prior CT, determined by premenopausal estradiol level within 8 months of CT completion. The primary endpoint was invasive disease-free survival (DFS; randomization until invasive local, regional, distant recurrence or contralateral breast; invasive second malignancy; death). Secondary endpoints included invasive breast cancer-free interval (BCFI), distant recurrence-free interval (DRFI) and OS. NCT00066690.

Results: DFS for patients assigned T+OFS (n=1015) was significantly improved over T (n=1018; HR=0.76 [95%CI 0.62-0.93]) and 8yr DFS was 83.2% vs 78.9%, respectively; BCFI and DRFI results were supportive (see Table). Hazard ratios for these 3 endpoints showed no heterogeneity by use of prior CT. For patients with prior CT, 8yr DFS was 76.7% with T+OFS vs 71.4% with T (Δ=5.3%); in those without CT, 8yr DFS was 90.6% vs 87.4% (Δ=3.2%). E+OFS (n=1014) improved outcomes relative to T (Table); 8yr DFS for E+OFS was 85.9% (80.4% with use of prior CT and 92.5% for those without CT). OS was improved with T+OFS vs T (8yr OS 93.3% vs 91.5%). 8yr OS was 92.1% with E+OFS. 201/225 deaths occurred in women with prior CT. For women without CT there have been 10, 5 and 9 deaths in the T+OFS, T and E+OFS groups (total n=1419), respectively, only half of these deaths after breast cancer event.

N. EventsHazard Ratio (95% CI)Endpoint(3 arms)T+OFS vs TE+OFS vs TDFS5180.76 (0.62-0.93) P=0.0090.65 (0.53-0.81)BCFI4370.76 (0.61-0.95)0.64 (0.51-0.81)DRFI3060.86 (0.66-1.13)0.73 (0.55-0.96)OS2250.67 (0.48-0.92)0.85 (0.62-1.15)

Overall toxicity was worse with T+ OFS than with T, including 32% vs 25% grade 3+ targeted AEs. Early cessation of tamoxifen occurred for 19% assigned T+OFS and 22% of women assigned T; the cumulative incidence of early cessation of triptorelin on the T+OFS arm was 23% by 4yrs. Early cessation of exemestane occurred for 28% and of triptorelin for 21% by 4yrs on the E+OFS arm.

Conclusions: With additional follow-up to a median of 8yrs, SOFT further supports the value of OFS for some premenopausal women. Follow-up continues, which will further clarify the safety and the benefit of OFS for late recurrence and overall survival. Oncologists appear to be able to select a low risk group (no chemotherapy) for whom treatment escalation is unlikely to improve survival.

Citation Format: Fleming G, Francis PA, Láng I, Ciruelos EM, Bellet M, Bonnefoi HR, Climent MA, Pavesi L, Burstein HJ, Martino S, Davidson NE, Geyer Jr CE, Walley BA, Coleman RE, Kerbrat P, Buchholz S, Ingle JN, Rabaglio-Poretti M, Colleoni M, Regan MM. Randomized comparison of adjuvant tamoxifen (T) plus ovarian function suppression (OFS) versus tamoxifen in premenopausal women with hormone receptor-positive (HR+) early breast cancer (BC): Update of the SOFT trial [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr GS4-03.

Concurrent and sequential initiation of ovarian function suppression with chemotherapy in premenopausal women with endocrine-responsive early breast cancer: an exploratory analysis of TEXT and SOFT

BACKGROUND

Recent breast cancer treatment guidelines recommend that higher-risk premenopausal patients should receive ovarian function suppression (OFS) as part of adjuvant endocrine therapy. If chemotherapy is also given, it is uncertain whether to select concurrent or sequential OFS initiation.

DESIGN AND METHODS

We analyzed 1872 patients enrolled in the randomized phase III TEXT and SOFT trials who received adjuvant chemotherapy for hormone receptor-positive, HER2-negative breast cancer and upon randomization to an OFS-containing adjuvant endocrine therapy, initiated gonadotropin-releasing-hormone-agonist triptorelin. Breast cancer-free interval (BCFI) was compared between patients who received OFS concurrently with chemotherapy in TEXT (n = 1242) versus sequentially post-chemotherapy in SOFT (n = 630). Because timing of trial enrollment relative to adjuvant chemotherapy differed, we implemented landmark analysis re-defining BCFI beginning 1 year after final dose of chemotherapy (median, 15.5 and 8.1 months from enrollment to landmark in TEXT and SOFT, respectively). As a non-randomized treatment comparison, we implemented comparative-effectiveness propensity score methodology with weighted Cox modeling.

RESULTS

Distributions of several clinico-pathologic characteristics differed between groups. Patients who were premenopausal post-chemotherapy in SOFT were younger on average. The median duration of adjuvant chemotherapy was 18 weeks in both groups. There were 231 (12%) BC events after post-landmark median follow-up of about 5 years. Concurrent use of triptorelin with chemotherapy was not associated with a significant difference in post-landmark BCFI compared with sequential triptorelin post-chemotherapy, either in the overall population (HR = 1.11, 95% CI 0.72-1.72; P = 0.72; 4-year BCFI 89% in both groups), or in the subgroup of 692 women <40 years at diagnosis (HR = 1.13, 95% CI 0.69-1.84) who are less likely to develop chemotherapy-induced amenorrhea.

CONCLUSION

Based on comparative-effectiveness modeling of TEXT and SOFT after about 5 years median follow-up, with limited statistical power especially for the subgroup <40 years, neither detrimental nor beneficial effect of concurrent administration of OFS with chemotherapy on the efficacy of adjuvant therapy that includes chemotherapy was detected.

CLINICALTRIALS.GOV

NCT00066690 and NCT00066703.

Randomized Phase III Trial of Trastuzumab Plus Capecitabine With or Without Pertuzumab in Patients With Human Epidermal Growth Factor Receptor 2-Positive Metastatic Breast Cancer Who Experienced Disease Progression During or After Trastuzumab-Based Therapy

Purpose To assess the efficacy and safety of trastuzumab plus capecitabine with or without pertuzumab in patients with human epidermal growth factor receptor 2-positive metastatic breast cancer who experienced disease progression during or after trastuzumab-based therapy and received a prior taxane. Patients and Methods Patients were randomly assigned to arm A: trastuzumab 8 mg/kg → 6 mg/kg once every 3 weeks plus capecitabine 1,250 mg/m² twice a day (2 weeks on, 1 week off, every 3 weeks); or arm B: pertuzumab 840 mg → 420 mg once every 3 weeks plus trastuzumab at the same dose and schedule as arm A plus capecitabine 1,000 mg/m² on the same schedule as arm A. The primary end point was independent review facility-assessed progression-free survival (IRF PFS). Secondary end points included overall survival (OS) and safety. Hierarchical testing procedures were used to control type I error for statistical testing of IRF PFS, OS, and objective response rate. Results Randomly assigned (intent-to-treat) populations were 224 and 228 patients in arms A and B, respectively. Median IRF PFS at 28.6 and 25.3 months' median follow-up was 9.0 v 11.1 months (hazard ratio, 0.82; 95% CI, 0.65 to 1.02; P = .0731) and interim OS was 28.1 v 36.1 months (hazard ratio, 0.68; 95% CI, 0.51 to 0.90). The most common adverse events (all grades; incidence of ≥ 10% in either arm and ≥ 5% difference between arms) were hand-foot syndrome, nausea, and neutropenia in arm A, and diarrhea, rash, and nasopharyngitis in arm B. Conclusion The addition of pertuzumab to trastuzumab and capecitabine did not significantly improve IRF PFS. An 8-month increase in median OS to 36.1 months with pertuzumab was observed. Statistical significance for OS cannot be claimed because of the hierarchical testing of OS after the primary PFS end point; however, the magnitude of OS difference is in keeping with prior experience of pertuzumab in metastatic breast cancer. No new safety signals were identified.

Cholesterol, Cholesterol-Lowering Medication Use, and Breast Cancer Outcome in the BIG 1-98 Study

Purpose

Cholesterol-lowering medication (CLM) has been reported to have a role in preventing breast cancer recurrence. CLM may attenuate signaling through the estrogen receptor by reducing levels of the estrogenic cholesterol metabolite 27-hydroxycholesterol. The impact of endocrine treatment on cholesterol levels and hypercholesterolemia per se may counteract the intended effect of aromatase inhibitors.

Patients and Methods

The Breast International Group (BIG) conducted a randomized, phase III, double-blind trial, BIG 1-98, which enrolled 8,010 postmenopausal women with early-stage, hormone receptor–positive invasive breast cancer from 1998 to 2003. Systemic levels of total cholesterol and use of CLM were measured at study entry and every 6 months up to 5.5 years. Cumulative incidence functions were used to describe the initiation of CLM in the presence of competing risks. Marginal structural Cox proportional hazards modeling investigated the relationships between initiation of CLM during endocrine therapy and outcome. Three time-to-event end points were considered: disease-free-survival, breast cancer–free interval, and distant recurrence–free interval.

Results

Cholesterol levels were reduced during tamoxifen therapy. Of 789 patients who initiated CLM during endocrine therapy, the majority came from the letrozole monotherapy arm (n = 318), followed by sequential tamoxifen-letrozole (n = 189), letrozole-tamoxifen (n = 176), and tamoxifen monotherapy (n = 106). Initiation of CLM during endocrine therapy was related to improved disease-free-survival (hazard ratio [HR], 0.79; 95% CI, 0.66 to 0.95; P = .01), breast cancer–free interval (HR, 0.76; 95% CI, 0.60 to 0.97; P = .02), and distant recurrence–free interval (HR, 0.74; 95% CI, 0.56 to 0.97; P = .03).

Conclusion

Cholesterol-lowering medication during adjuvant endocrine therapy may have a role in preventing breast cancer recurrence in hormone receptor–positive early-stage breast cancer. We recommend that these observational results be addressed in prospective randomized trials.

Abstract P2-09-05: 12 years' median follow up (MFU) of BIG 1-98: Adjuvant letrozole, tamoxifen and their sequence for postmenopausal women with endocrine responsive early breast cancer

Background

The Breast International Group (BIG) 1-98 study is a randomized, phase 3, double-blind trial that compared five yrs of adjuvant treatment with letrozole, tamoxifen, or their sequence in postmenopausal women with hormone-receptor–positive early breast cancer. The study is conducted by the International Breast Cancer Study Group (IBCSG) on behalf of BIG. 8010 patients (pts) were enrolled between March 1998 and May 2003, and first results demonstrating a significant DFS benefit favoring letrozole compared with tamoxifen were reported in 2005 at 25.8 months' MFU. Subsequent updates showed continuing DFS benefit and updated results published in 2011 at 8.1 yrs' MFU showed OS benefit. Industry-sponsorship of the original BIG 1-98 ended in 2010; IBCSG launched an observational, non-interventional long-term follow-up study (BIG 1-98 LTFU) to collect survival, disease status and adverse events for an additional 5 yrs. We report results from BIG 1-98 LTFU at 12 yrs' MFU.

Methods

The original trial includes the 8010 patients enrolled. The potential BIG 1-98 LTFU cohort consisted of 148 academic medical centers with a maximum of 6843 pts who were alive and continuing follow-up when the original study ended. Response bias was addressed using weighting class adjustments estimated using multivariable logistic regression. Unadjusted incidence rates are reported here per 1000 pt-yrs with 95% Poisson confidence intervals. An updated abstract will include adjusted incidence rates, as well as estimates of OS and DFS based on a weighted Kaplan-Meier approach. The database will close in July 2016.

Results

As of May 2016, 81 centers participated in the BIG 1-98 LTFU study, contributing data from approximately 3900 pts (57%) and extending MFU to 12 yrs. Compared with the potential cohort of 6843 pts, the ~3900 in the LTFU analytic cohort were more likely to be under age 65 yrs at enrollment, have node-positive disease, and have tumors that were &lt; 2 cm, PgR positive (≥1%), and with no evidence of peritumoral vascular invasion. Extended adjuvant endocrine therapy for primary BC was continued in 2% of pts. Unadjusted incidence estimates of myocardial infarction increased during LTFU, while incidence of thromboembolic events and osteoporosis decreased (Table). Variations in incidence rates were noted depending on recording mechanism (e.g. registry, clinic visit, telephone, information from family).

 Unadjusted Incidence Rate/1000 pt-yrs (95% CI)Adverse EventDuring original studyDuring LTFUMyocardial Infarction1.7 (1.4-2.0)3.5 (2.7-4.5)Thromboembolic event6.0 (5.4-6.6)2.5 (1.8-3.3)Osteoporosis23.6 (22.5-24.9)18.2 (16.3-20.3)Bone fractures17.2 (16.2-18.3)15.0 (13.2-16.9)

Overall 1845 deaths were reported; the unadjusted incidence of death was lower in the original study compared with during LTFU (21.9 vs. 26.6/1000 pt-yrs); incidence remained relatively stable for pts assigned to tamoxifen (24.9 vs. 25.2/1000 pt-yrs), and increased for pts assigned to letrozole (22.0 vs. 27.1/1000 pt-yrs).

Conclusions

The BIG 1-98 LTFU study has been successfully conducted. The additional data from the BIG 1-98 LTFU study provides important long-term clinical information about OS, DFS and adverse events.

Citation Format: Thürlimann B, Giobbie-Hurder A, Colleoni M, Jensen M-B, Ejlertsen B, de Azambuja E, Neven P, Láng I, Gladieff L, Bonnefoi H, Harvey VJ, Spazzapan S, Tondini C, Price K, Piccart-Gebhart M, Regan MM, Gelber RD, Coates AS, Goldhirsch A. 12 years' median follow up (MFU) of BIG 1-98: Adjuvant letrozole, tamoxifen and their sequence for postmenopausal women with endocrine responsive early breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-09-05.

Randomized Phase III Trial of Erlotinib versus Docetaxel in Patients with Advanced Squamous Cell Non-Small Cell Lung Cancer Failing First-Line Platinum-Based Doublet Chemotherapy Stratified by VeriStrat Good versus VeriStrat Poor. The European Thoracic Oncology Platform (ETOP) EMPHASIS-lung Trial

INTRODUCTION

Docetaxel and erlotinib are registered second-line treatments for wild-type EGFR NSCLC. Previous studies suggested a predictive value of the VeriStrat test in second-line therapy of NSCLC, classifying patients as either VeriStrat good or VeriStrat poor. EMPHASIS-lung aimed at exploring this predictive effect in patients with squamous cell NSCLC. The trial closed prematurely because of low accrual and results from other trials. Our analysis includes an exploratory combined analysis with results from the PROSE trial.

METHODS

EMPHASIS-lung was a randomized phase III multicenter trial exploring the differential effect of second-line erlotinib versus docetaxel on progression-free survival (PFS) in VeriStrat good versus VeriStrat poor patients with squamous cell NSCLC.

RESULTS

A total of 80 patients were randomized, with 72.5% categorized as VeriStrat good. Patient characteristics were balanced between VeriStrat status and treatment groups. The median PFS times with docetaxel and erlotinib treatment in the VeriStrat good cohort were 4.1 and 1.6 months, respectively, versus 1.9 and 2.1 months, respectively, in the VeriStrat poor cohort. The median overall survival (OS) times with docetaxel and erlotinib treatment in the VeriStrat good cohort were 7.8 and 8.4 months, respectively, and 4.4 and 5.2 months, respectively, in the VeriStrat poor cohort. An additional exploratory analysis was performed; in it, 47 patients from the squamous cell subgroup of PROSE were included in a combined analysis, contributing with 45 PFS and 41 OS events.

CONCLUSIONS

The final analysis of EMPHASIS-lung did not show a differential effect on PFS for erlotinib versus docetaxel stratified by VeriStrat status. Similarly, in the combined analysis, no significant treatment by VeriStrat status interaction was observed (interaction p = 0.24 for PFS and 0.45 for OS, stratified by study).

Poor Prognosis After Second Locoregional Recurrences in the CALOR Trial

BACKGROUND

Isolated locoregional recurrences (ILRRs) of breast cancer confer a significant risk for the development of distant metastasis. Management practices and second ILRR events in the Chemotherapy as Adjuvant for LOcally Recurrent breast cancer (CALOR) trial were investigated.

METHODS

In this study, 162 patients with ILRR were randomly assigned to receive postoperative chemotherapy or no chemotherapy. Descriptive statistics characterize outcomes according to local therapy and the influence of hormone receptor status on subsequent recurrences. Competing risk regression models, Kaplan-Meier estimates, and Cox proportional hazards models were used to evaluate associations between treatment, site of second recurrence, and outcome.

RESULTS

The median follow-up period was 4.9 years. Of the 98 patients who received breast-conserving primary surgery 89 had an ipsilateral-breast tumor recurrence. Salvage mastectomy was performed for 73 patients and repeat lumpectomy for 16 patients. Another eight patients had nodal ILRR, and one patient had chest wall ILRR. Among 64 patients whose primary surgery was mastectomy, 52 had chest wall/skin ILRR, and 12 had nodal ILRR. For 15 patients, a second ILRR developed a median of 1.6 years (range 0.08-4.8 years) after ILRR. All second ILRRs occurred for patients with progesterone receptor-negative ILRR. Death occurred for 7 (47 %) of 15 patients with a second ILRR and 19 (51 %) of 37 patients with a distant recurrence. As shown in the multivariable analysis, the significant predictors of survival after either a second ILRR or distant recurrence were chemotherapy for the primary cancer (hazard ratio [HR], 3.55; 95 % confidence interval [CI], 1.15-10.9; p = 0.03) and the interval (continuous) from the primary surgery (HR, 0.87; 95 % CI, 0.75-1.00; p = 0.05).

CONCLUSIONS

Second ILRRs represented about one third of all recurrence events after ILRR, and all were PR-negative. These second ILRRs and distant metastases portend an unfavorable outcome.

Low-Dose Oral Cyclophosphamide and Methotrexate Maintenance for Hormone Receptor-Negative Early Breast Cancer: International Breast Cancer Study Group Trial 22-00

PURPOSE

To evaluate the benefit of low-dose cyclophosphamide and methotrexate (CM) maintenance, which previously demonstrated antitumor activity and few adverse effects in advanced breast cancer, in early breast cancer.

PATIENTS AND METHODS

International Breast Cancer Study Group (IBCSG) Trial 22-00, a randomized phase III clinical trial, enrolled 1,086 women (1,081 intent-to-treat) from November 2000 to December 2012. Women with estrogen receptor- and progesterone receptor-negative (< 10% positive cells by immunohistochemistry) early breast cancer any nodal and human epidermal growth factor receptor 2 status, were randomly assigned anytime between primary surgery and 56 days after the first day of last course of adjuvant chemotherapy to CM maintenance (cyclophosphamide 50 mg/day orally continuously and methotrexate 2.5 mg twice/day orally on days 1 and 2 of every week for 1 year) or to no CM. The primary end point was disease-free survival (DFS), which included invasive recurrences, second (breast and nonbreast) malignancies, and deaths.

RESULTS

After a median of 6.9 years of follow-up, DFS was not significantly better for patients assigned to CM maintenance compared with patients assigned to no CM, both overall (hazard ratio [HR], 0.84; 95% CI, 0.66 to 1.06;P = .14) and in triple-negative (TN) disease (n = 814; HR, 0.80; 95% CI, 0.60 to 1.06). Patients with TN, node-positive disease had a nonstatistically significant reduced HR (n = 340; HR, 0.72; 95% CI, 0.49 to 1.05). Seventy-one (13%) of 542 patients assigned to CM maintenance did not start CM. Of 473 patients who received at least one CM maintenance dose (including two patients assigned to no CM), 64 (14%) experienced a grade 3 or 4 treatment-related adverse event; elevated serum transaminases was the most frequently reported (7%), followed by leukopenia (2%).

CONCLUSION

CM maintenance did not produce a significant reduction in DFS events in hormone receptor-negative early breast cancer. The trend toward benefit observed in the TN, node-positive subgroup supports additional exploration of this strategy in the TN, higher-risk population.

Treatment Adherence and Its Impact on Disease-Free Survival in the Breast International Group 1-98 Trial of Tamoxifen and Letrozole, Alone and in Sequence

PURPOSE

To investigate adherence to endocrine treatment and its relationship with disease-free survival (DFS) in the Breast International Group (BIG) 1-98 clinical trial.

METHODS

The BIG 1-98 trial is a double-blind trial that randomly assigned 6,193 postmenopausal women with hormone receptor-positive early breast cancer in the four-arm option to 5 years of tamoxifen (Tam), letrozole (Let), or the agents in sequence (Let-Tam, Tam-Let). This analysis included 6,144 women who received at least one dose of study treatment. Conditional landmark analyses and marginal structural Cox proportional hazards models were used to evaluate the relationship between DFS and treatment adherence (persistence [duration] and compliance with dosage). Competing risks regression was used to assess demographic, disease, and treatment characteristics of the women who stopped treatment early because of adverse events.

RESULTS

Both aspects of low adherence (early cessation of letrozole and a compliance score of < 90%) were associated with reduced DFS (multivariable model hazard ratio, 1.45; 95% CI, 1.09 to 1.93; P = .01; and multivariable model hazard ratio, 1.61; 95% CI, 1.08 to 2.38; P = .02, respectively). Sequential treatments were associated with higher rates of nonpersistence (Tam-Let, 20.8%; Let-Tam, 20.3%; Tam 16.9%; Let 17.6%). Adverse events were the reason for most trial treatment early discontinuations (82.7%). Apart from sequential treatment assignment, reduced adherence was associated with older age, smoking, node negativity, or prior thromboembolic event.

CONCLUSION

Both persistence and compliance are associated with DFS. Toxicity management and, for sequential treatments, patient and physician awareness, may improve adherence.

Absolute Benefit of Adjuvant Endocrine Therapies for Premenopausal Women With Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Early Breast Cancer: TEXT and SOFT Trials

PURPOSE

Risk of recurrence is the primary consideration in breast cancer adjuvant therapy recommendations. The TEXT (Tamoxifen and Exemestane Trial) and SOFT (Suppression of Ovarian Function Trial) trials investigated adjuvant endocrine therapies for premenopausal women with hormone receptor-positive breast cancer, testing exemestane plus ovarian function suppression (OFS), tamoxifen plus OFS, and tamoxifen alone. We examined absolute treatment effect across a continuum of recurrence risk to individualize endocrine therapy decision making for premenopausal women with human epidermal growth factor receptor 2 (HER2) -negative disease.

PATIENTS AND METHODS

The TEXT and SOFT hormone receptor-positive, HER2-negative analysis population included 4,891 women. The end point was breast cancer-free interval (BCFI), defined as time from random assignment to first occurrence of invasive locoregional, distant, or contralateral breast cancer. A continuous, composite measure of recurrence risk for each patient was determined from a Cox model incorporating age, nodal status, tumor size and grade, and estrogen receptor, progesterone receptor, and Ki-67 expression levels. Subpopulation treatment effect pattern plot methodology revealed differential treatment effects on 5-year BCFI according to composite risk.

RESULTS

SOFT patients who remained premenopausal after chemotherapy experienced absolute improvement of 5% or more in 5-year BCFI with exemestane plus OFS versus tamoxifen plus OFS or tamoxifen alone, reaching 10% to 15% at intermediate to high composite risk; the benefit of tamoxifen plus OFS versus tamoxifen alone was apparent at the highest composite risk. The SOFT no-chemotherapy cohort-for whom composite risk was lowest on average-did well with all endocrine therapies. For TEXT patients, the benefit of exemestane plus OFS versus tamoxifen plus OFS in 5-year BCFI ranged from 5% to 15%; patients not receiving chemotherapy and with lowest composite risk did well with both treatments.

CONCLUSION

Premenopausal women with hormone receptor-positive, HER2-negative disease and high recurrence risk, as defined by clinicopathologic characteristics, may experience improvement of 10% to 15% in 5-year BCFI with exemestane plus OFS versus tamoxifen alone. An improvement of at least 5% may be achieved for women at intermediate risk, and improvement is minimal for those at lowest risk.

Twelve-Month Estrogen Levels in Premenopausal Women With Hormone Receptor-Positive Breast Cancer Receiving Adjuvant Triptorelin Plus Exemestane or Tamoxifen in the Suppression of Ovarian Function Trial (SOFT): The SOFT-EST Substudy

PURPOSE

To describe estradiol (E2), estrone (E1), and estrone sulfate (E1S) levels during the first year of monthly triptorelin plus exemestane or tamoxifen and to assess possible suboptimal suppression while receiving exemestane plus triptorelin.

PATIENTS AND METHODS

Premenopausal patients with early breast cancer on the Suppression of Ovarian Function Trial who selected triptorelin as the ovarian suppression method and were randomly assigned to exemestane plus triptorelin or tamoxifen plus triptorelin were enrolled until the target population of 120 patients was reached. Blood sampling time points were 0, 3, 6, 12, 18, 24, 36, and 48 months. Serum estrogens were measured with a highly sensitive and specific assay. This preplanned 12-month analysis evaluated E2, E1, E1S, follicle-stimulating hormone, and luteinizing hormone levels in all patients and the proportion of patients with E2 levels greater than 2.72 pg/mL at any time point during treatment with exemestane plus triptorelin.

RESULTS

One hundred sixteen patients (exemestane, n = 86; tamoxifen, n = 30; median age, 44 years; median E2, 51 pg/mL; 55% prior chemotherapy) started triptorelin and had one or more samples drawn. With exemestane plus triptorelin, median reductions from baseline E2, E1, and E1S levels were consistently ≥ 95%, resulting in significantly lower levels than with tamoxifen plus triptorelin at all time points. Among patients on exemestane plus triptorelin, 25%, 24%, and 17% had an E2 level greater than 2.72 pg/mL at 3, 6, and 12 months, respectively. Baseline factors related to on-treatment E2 level greater than 2.72 pg/mL were no prior chemotherapy (P = .06), higher body mass index (P = .05), and lower follicle-stimulating hormone and luteinizing hormone (each P < .01).

CONCLUSION

During the first year, most patients on exemestane plus triptorelin had E2 levels below the defined threshold of 2.72 pg/mL, consistent with levels reported in postmenopausal patients on aromatase inhibitors, but at each time point, at least 17% of patients had levels greater than the threshold.

Serum estrone concentration, estrone sulfate/estrone ratio and BMI are associated with human epidermal growth factor receptor 2 and progesterone receptor status in postmenopausal primary breast cancer patients suffering invasive ductal carcinoma

Background

We investigated in postmenopausal women with primary breast cancer prior to surgical intervention whether, serum levels of different steroid hormones and hormonal precursors associated with tumor tissue estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) status.

Methods

We enrolled 1,042 patients suffering invasive ductal carcinoma undergoing surgical resection in the National Institute of Oncology, Hungary between 2003 and 2011. Serum parameters were measured by RIA/IRMA assays; tumor tissue ER, PR and HER2 status was assessed histologically. Patients were classified according to tumor receptor status. Case–case analysis subjects were categorized into four subgroups based on serum hormone concentrations in ER, PR and HER2 receptor-negative cases, respectively.

Results

Serum estrone sulfate and dehydroepiandrosterone sulfate levels correlated with each other and also with serum estrone and estradiol levels. According to case–case study the odds ratios in the highest quartile were 1.517 (p = 0.0305, P_trend = 0.0394) for androstenedione, 1.495 (p = 0.0317, P_trend < 0.0105) for estrone and 0.654 (p = 0.0273, P_trend < 0.0151) for estrone sulfate/estrone ratio in PR+ vs. PR− tumors. Regarding HER2 status (HER2+ vs. HER2−), the odds ratios for estrone, estrone sulfate and estrone sulfate/estrone ratio were 0.530 (p = 0.0234, P_trend = 0.0595), 2.438 (p = 0.0042, P_trend < 0.0066) and 3.118 (p = 0.0001, P_trend < 0.0001) in the highest quartile, respectively. Of note significantly increased BMI associates with PR+ and ER +/PR+ status while significantly decreased BMI was observed in HER2+ cases.

Conclusions

Taken together, measurement of serum estrone and estrone sulfate concentrations prior to surgical intervention might support the individualization of regime in postmenopausal primary breast cancer patients.

Abstract P4-18-03: IBCSG BIG 1-98 study: The long-term follow-up experience

Background

Industry-sponsored clinical trials often have duration of patient follow-up that is defined according to regulatory requirements. However, in diseases such as endocrine-responsive, early breast cancer, recurrences occur after protocol follow-up, and monitoring of long-term toxicity is important. It is challenging to continue patient follow-up after industry sponsorship ends. Transferring responsibility for additional follow-up to the participating academic centers is required. One such example is the long-term follow-up (LTFU) of patients in the Breast International Group (BIG) 1-98 Trial. We present the procedures and current status of the BIG 1-98 LTFU protocol.

Methods

In 2010, the BIG 1-98 trial embarked on a new LTFU protocol to gather data on patient outcomes for an additional five years after study completion (2011-2015). Industry sponsorship ceased at the end of 2010. The LTFU study is designed as an observational, non-interventional study to continue the collection of simplified and updated data on survival, disease status, and long-term adverse events from centers participating in the 4-arm option. The International Breast Cancer Study Group (IBCSG) is sponsoring BIG 1-98 LTFU, and per case reimbursement is available.

Results

The potential BIG 1-98 LTFU cohort consists of the 148 academic medical centers that participated in the 4-arm option with a maximum of 6843 patients enrolled to the parent study. In May 2014, approximately 3 years after initiation of the LTFU protocol, 96 centers had agreed to participate, of which 67 sites had activated the protocol and submitted LTFU data; 31 additional centers were not participating, and the status of 21 centers was unknown.

Participation StatusNumber of CentersPatients Enrolled in BIG 1-98Closed317Not Participating28643No response/Unknown21850Yes, participating965333 Activated674215Not Activated291118Totals1486843

Because the original BIG 1-98 informed consent indicated life-long follow-up, only three countries required patient re-consent in order to participate. At least one LTFU data submission has occurred for 73% of patients participating in the LTFU (May 2014).

Conclusion

Long-term follow-up for a large-scale clinical trial is feasible, but challenging. The methods used for BIG 1-98 LTFU will be described and the status will be updated at the meeting.

Citation Format: Anita Giobbie-Hurder, Beat Thürlimann, Bent Ejlertsen, Patrick Neven, Robert E Coleman, Ian Smith, Andrew M Wardley, István Láng, Marco Colleoni, Marc Debled, John F Forbes, Karen N Price, Meredith M Regan, Manuela Rabaglio, Aron Goldhirsch, Alan S Coates, Richard D Gelber. IBCSG BIG 1-98 study: The long-term follow-up experience [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-18-03.

Adjuvant ovarian suppression in premenopausal breast cancer

BACKGROUND

Suppression of ovarian estrogen production reduces the recurrence of hormone-receptor-positive early breast cancer in premenopausal women, but its value when added to tamoxifen is uncertain.

METHODS

We randomly assigned 3066 premenopausal women, stratified according to prior receipt or nonreceipt of chemotherapy, to receive 5 years of tamoxifen, tamoxifen plus ovarian suppression, or exemestane plus ovarian suppression. The primary analysis tested the hypothesis that tamoxifen plus ovarian suppression would improve disease-free survival, as compared with tamoxifen alone. In the primary analysis, 46.7% of the patients had not received chemotherapy previously, and 53.3% had received chemotherapy and remained premenopausal.

RESULTS

After a median follow-up of 67 months, the estimated disease-free survival rate at 5 years was 86.6% in the tamoxifen-ovarian suppression group and 84.7% in the tamoxifen group (hazard ratio for disease recurrence, second invasive cancer, or death, 0.83; 95% confidence interval [CI], 0.66 to 1.04; P=0.10). Multivariable allowance for prognostic factors suggested a greater treatment effect with tamoxifen plus ovarian suppression than with tamoxifen alone (hazard ratio, 0.78; 95% CI, 0.62 to 0.98). Most recurrences occurred in patients who had received prior chemotherapy, among whom the rate of freedom from breast cancer at 5 years was 82.5% in the tamoxifen-ovarian suppression group and 78.0% in the tamoxifen group (hazard ratio for recurrence, 0.78; 95% CI, 0.60 to 1.02). At 5 years, the rate of freedom from breast cancer was 85.7% in the exemestane-ovarian suppression group (hazard ratio for recurrence vs. tamoxifen, 0.65; 95% CI, 0.49 to 0.87).

CONCLUSIONS

Adding ovarian suppression to tamoxifen did not provide a significant benefit in the overall study population. However, for women who were at sufficient risk for recurrence to warrant adjuvant chemotherapy and who remained premenopausal, the addition of ovarian suppression improved disease outcomes. Further improvement was seen with the use of exemestane plus ovarian suppression. (Funded by Pfizer and others; SOFT ClinicalTrials.gov number, NCT00066690.).

Adjuvant exemestane with ovarian suppression in premenopausal breast cancer

BACKGROUND

Adjuvant therapy with an aromatase inhibitor improves outcomes, as compared with tamoxifen, in postmenopausal women with hormone-receptor-positive breast cancer.

METHODS

In two phase 3 trials, we randomly assigned premenopausal women with hormone-receptor-positive early breast cancer to the aromatase inhibitor exemestane plus ovarian suppression or tamoxifen plus ovarian suppression for a period of 5 years. Suppression of ovarian estrogen production was achieved with the use of the gonadotropin-releasing-hormone agonist triptorelin, oophorectomy, or ovarian irradiation. The primary analysis combined data from 4690 patients in the two trials.

RESULTS

After a median follow-up of 68 months, disease-free survival at 5 years was 91.1% in the exemestane-ovarian suppression group and 87.3% in the tamoxifen-ovarian suppression group (hazard ratio for disease recurrence, second invasive cancer, or death, 0.72; 95% confidence interval [CI], 0.60 to 0.85; P<0.001). The rate of freedom from breast cancer at 5 years was 92.8% in the exemestane-ovarian suppression group, as compared with 88.8% in the tamoxifen-ovarian suppression group (hazard ratio for recurrence, 0.66; 95% CI, 0.55 to 0.80; P<0.001). With 194 deaths (4.1% of the patients), overall survival did not differ significantly between the two groups (hazard ratio for death in the exemestane-ovarian suppression group, 1.14; 95% CI, 0.86 to 1.51; P=0.37). Selected adverse events of grade 3 or 4 were reported for 30.6% of the patients in the exemestane-ovarian suppression group and 29.4% of those in the tamoxifen-ovarian suppression group, with profiles similar to those for postmenopausal women.

CONCLUSIONS

In premenopausal women with hormone-receptor-positive early breast cancer, adjuvant treatment with exemestane plus ovarian suppression, as compared with tamoxifen plus ovarian suppression, significantly reduced recurrence. (Funded by Pfizer and others; TEXT and SOFT ClinicalTrials.gov numbers, NCT00066703 and NCT00066690, respectively.).

[BOLERO -- another remarkable step in treatment of breast cancer]

The expansion of molecular genetic knowledge leads to targeted therapy which is a common part of cancer treatment. Targeted agents also exist for breast cancer. However, new efficient molecules are urgently needed. On one hand, there are cancer subgroups where we do not have efficient targeted drugs, on the other hand, the results of established cancer therapies can be improved by interfering with another signal transduction pathway. Everolimus is a targeted agent which was effective in several clinical trials and became registered for treatment of hormone receptor positive breast cancer. This article summarizes the results of published breast cancer everolimus trials. The results of two phase 3 trials are available. In the BOLERO-2 trial exemestane was compared with the combination of exemestane and everolimus, while in BOLERO-3 trial trastuzumab and vinorelbine were investigated with or without everolimus. In both trials the progression-free survival was significantly longer in the experimental arm. The overall survival data of BOLERO-2 trial, a secondary end point, are also available. The 4.4 month benefit in the experimental arm is clinically important but it has not reached the level of statistical significance. We have not had biomarkers so far that could help us to identify a subgroup of cancers sensitive to everolimus.

[Preoperative chemotherapy in the surgical treatment of colorectal liver metastases]

INTRODUCTION

The only curative treatment of colorectal liver metastases (CRLM) is surgical resection. Preoperative/neoadjuvant chemotherapy can be used for resectable, for borderline resectable or even for irresectable CRLM patients.

PATIENTS

Data of CRLM patients treated with surgical resection at the Uzsoki Hospital were analysed. Patients were classified into two groups, (A) who received preoperative chemotherapy before hepatic resection, and (B) who received no chemotherapy before resection.

RESULTS

Between 01.01.2007. and 31.12.2010. 128 CRLM patients were treated with hepatic resection. 68 patients (53%) received chemotherapy before hepatic resection, 60 patients (47%) were resected without neoadjuvant chemotherapy. There was no significant difference in the complications between the groups (p = 0.39). Median overall survival was 41 months. The progression free survival (PFS) at 3 and 5 years were 25%, the 3 and 5 year overall survival (OS) were 55% and 31%. Both PFS and OS were significantly worse in the chemotherapy group (p = 0.014, p = 0.015). The subgroup of patients receiving bevacizumab containing preoperative chemotherapy has significanly better PFS than patients receiving only cytotoxic chemotherapy (p = 0.004).

CONCLUSION

Surgical resection of CRLM patients results good survival data even in non-selected patients, although the very long survival results reported in the literature couldn't have been reproduced in this patient population. When preoperative chemotherapy was combined with bevacizumab, survival was similar to the upfront resected patients.

Bosutinib in combination with the aromatase inhibitor exemestane: a phase II trial in postmenopausal women with previously treated locally advanced or metastatic hormone receptor-positive/HER2-negative breast cancer

BACKGROUND

Bosutinib is an oral, selective Src/Abl tyrosine kinase inhibitor with activity in breast cancer (BC). We evaluated bosutinib plus exemestane as second-line therapy in previously treated hormone receptor-positive (HR+) locally advanced or metastatic BC.

METHODS

This was a phase II study with patients enrolled in a single-arm safety lead-in phase. Patients receiving bosutinib at 400 mg or 300 mg/day (based on toxicity) plus exemestane at 25 mg/day were monitored for adverse events (AEs) and dose-limiting toxicities for 28 days, and initial efficacy was assessed. After the lead-in and dose-determination phase, randomized evaluation of combination therapy versus exemestane was planned.

RESULTS

Thirty-nine of 42 patients (93%) experienced treatment-related AEs including diarrhea in 28 (67%) and hepatotoxicity in 11 (26%); overall serious treatment-related AEs were recorded in 4 (10%). No liver toxicity met Hy's law criteria. Dose-limiting toxicities occurred in 5 of 13 patients receiving 400 mg (38%) and 3 of 26 patients receiving 300 mg (12%) of bosutinib; all resolved on treatment discontinuation. One patient (300 mg/day) achieved confirmed partial response; three (400 mg/day, n = 2; 300 mg/day, n = 1) maintained stable disease for >24 weeks; a best response of progressive disease occurred in 15 of 42 patients (36%). Median progression-free survival was 12.3 weeks (80% confidence interval: 11.0-15.6).

CONCLUSION

The risk-benefit profile of bosutinib at 300 mg/day plus exemestane resulted in early study termination before the randomized portion. Alternative bosutinib regimens merit investigation in BC.

Bosutinib in combination with the aromatase inhibitor letrozole: a phase II trial in postmenopausal women evaluating first-line endocrine therapy in locally advanced or metastatic hormone receptor-positive/HER2-negative breast cancer

BACKGROUND

Endocrine therapy resistance in hormone receptor-positive (HR+) breast cancer (BC) may involve crosstalk between HRs and growth factor signaling pathways. We evaluated bosutinib, a dual Src/Abl tyrosine kinase inhibitor that has previously demonstrated some antitumor activity in BC, plus letrozole as first-line endocrine therapy in locally advanced or metastatic HR+/HER2- BC. METHODS; Sixteen postmenopausal women were enrolled in a phase II study evaluating the safety/efficacy of bosutinib plus letrozole. In the single-arm safety/dose-confirming lead-in (part 1), patients received oral bosutinib at 400 mg/day plus letrozole at 2.5 mg/day; adverse events (AEs) and dose-limiting toxicities (DLTs) were monitored, and initial efficacy was assessed. A randomized efficacy/safety phase (part 2) was planned to evaluate the combination versus letrozole monotherapy.

RESULTS

Fifteen of 16 subjects experienced treatment-related AEs, most commonly diarrhea (69%). Treatment-related hepatotoxicity AEs (primarily alanine aminotransferase [ALT] or aspartate aminotransferase [AST] elevations) occurred in 6 of 16 patients (38%). Four of 15 evaluable patients (27%) experienced a DLT (grade 3/4 ALT/AST elevations, n = 2; grade 3 rash, n = 1; grade 3 diarrhea or vomiting, n = 1), including 1 Hy's law hepatotoxicity case. All DLTs resolved following treatment discontinuation. One patient achieved confirmed partial response; one had stable disease for >24 weeks. Study termination occurred before part 2.

CONCLUSION

The unfavorable risk-benefit ratio did not warrant further investigation of bosutinib plus letrozole.

Chemotherapy for isolated locoregional recurrence of breast cancer (CALOR): a randomised trial

BACKGROUND

Patients with isolated locoregional recurrences (ILRR) of breast cancer have a high risk of distant metastasis and death from breast cancer. We aimed to establish whether adjuvant chemotherapy improves the outcome of such patients.

METHODS

The CALOR trial was a pragmatic, open-label, randomised trial that accrued patients with histologically proven and completely excised ILRR after unilateral breast cancer who had undergone a mastectomy or lumpectomy with clear surgical margins. Eligible patients were enrolled from hospitals worldwide and were centrally randomised (1:1) to chemotherapy (type selected by the investigator; multidrug for at least four courses recommended) or no chemotherapy, using permuted blocks, and stratified by previous chemotherapy, oestrogen-receptor and progesterone-receptor status, and location of ILRR. Patients with oestrogen-receptor-positive ILRR received adjuvant endocrine therapy, radiation therapy was mandated for patients with microscopically involved surgical margins, and anti-HER2 therapy was optional. The primary endpoint was disease-free survival. All analyses were by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00074152.

FINDINGS

From Aug 22, 2003, to Jan 31, 2010, 85 patients were randomly assigned to receive chemotherapy and 77 were assigned to no chemotherapy. At a median follow-up of 4·9 years (IQR 3·6-6 ·0), 24 (28%) patients had disease-free survival events in the chemotherapy group compared with 34 (44%) in the no chemotherapy group. 5-year disease-free survival was 69% (95% CI 56-79) with chemotherapy versus 57% (44-67) without chemotherapy (hazard ratio 0·59 [95% CI 0·35-0·99]; p=0·046). Adjuvant chemotherapy was significantly more effective for women with oestrogen-receptor-negative ILRR (pinteraction=0·046), but analyses of disease-free survival according to the oestrogen-receptor status of the primary tumour were not statistically significant (pinteraction=0·43). Of the 81 patients who received chemotherapy, 12 (15%) had serious adverse events. The most common adverse events were neutropenia, febrile neutropenia, and intestinal infection.

INTERPRETATION

Adjuvant chemotherapy should be recommended for patients with completely resected ILRR of breast cancer, especially if the recurrence is oestrogen-receptor negative.

FUNDING

US Department of Health and Human Services, Swiss Group for Clinical Cancer Research (SAKK), Frontier Science and Technology Research Foundation, Australian and New Zealand Breast Cancer Trials Group, Swedish Cancer Society, Oncosuisse, Cancer Association of South Africa, Foundation for Clinical Research of Eastern Switzerland (OSKK), Grupo Español de Investigación en Cáncer de Mama (GEICAM), and the Dutch Breast Cancer Trialists' Group (BOOG).

Symptoms of endocrine treatment and outcome in the BIG 1-98 study

There may be a relationship between the incidence of vasomotor and arthralgia/myalgia symptoms and treatment outcomes for postmenopausal breast cancer patients with endocrine-responsive disease who received adjuvant letrozole or tamoxifen. Data on patients randomized into the monotherapy arms of the BIG 1-98 clinical trial who did not have either vasomotor or arthralgia/myalgia/carpal tunnel (AMC) symptoms reported at baseline, started protocol treatment and were alive and disease-free at the 3-month landmark (n = 4,798) and at the 12-month landmark (n = 4,682) were used for this report. Cohorts of patients with vasomotor symptoms, AMC symptoms, neither, or both were defined at both 3 and 12 months from randomization. Landmark analyses were performed for disease-free survival (DFS) and for breast cancer free interval (BCFI), using regression analysis to estimate hazard ratios (HR) and 95 % confidence intervals (CI). Median follow-up was 7.0 years. Reporting of AMC symptoms was associated with better outcome for both the 3- and 12-month landmark analyses [e.g., 12-month landmark, HR (95 % CI) for DFS = 0.65 (0.49-0.87), and for BCFI = 0.70 (0.49-0.99)]. By contrast, reporting of vasomotor symptoms was less clearly associated with DFS [12-month DFS HR (95 % CI) = 0.82 (0.70-0.96)] and BCFI (12-month DFS HR (95 % CI) = 0.97 (0.80-1.18). Interaction tests indicated no effect of treatment group on associations between symptoms and outcomes. While reporting of AMC symptoms was clearly associated with better DFS and BCFI, the association between vasomotor symptoms and outcome was less clear, especially with respect to breast cancer-related events.

Abstract P4-12-18: BOLERO-3: Quality-of-life maintained in patients with metastatic breast cancer treated with everolimus plus trastuzumab plus vinorelbine

Background: Activation of the PI3K/mTOR pathway is implicated in resistance to trastuzumab. Accordingly, the BOLERO-3 study evaluated the efficacy of adding everolimus (EVE), an mTOR inhibitor, to vinorelbine and trastuzumab. At the final progression-free survival (PFS) analysis, EVE significantly improved PFS vs PBO (hazard ratio [HR] = 0.78; log-rank P = .0067) but EVE-treated patients had higher rate of grade 3/4 toxicity. To further qualify the benefit:risk of adding EVE to trastuzumab-based therapy, per-protocol, patient-reported, health-related quality-of-life (HRQoL) data were analyzed.

Methods: BOLERO-3 is a randomized phase 3, double-blind, placebo-controlled, international multicenter trial. Taxane-pretreated patients (N = 569) with trastuzumab-resistant, HER2+, advanced breast cancer were randomized (1:1) to treatment with EVE or placebo (PBO) plus vinorelbine and trastuzumab. The European Organisation for Research and Treatment of Cancer (EORTC) quality-of-life questionnaire C30 (QLQ-C30) (including the breast cancer-specific BR23 module) was administered at baseline and every 6 weeks thereafter until progression. The QLQ-C30 consists of 30 items combined into 15 subscales, including Global Health Status and functional subscales, where higher scores (range, 0 to 100) indicate better HRQoL. Time to definitive deterioration (TTD) based on a 10% decrease from baseline for GHS and for the physical, emotional, and social function subscales was determined using the Kaplan-Meier method. Treatment arms were compared using a 2-sided log-rank test stratified by prior use of lapatinib.

Results: Overall, there was no significant difference in median TDD of HRQoL between treatment arms. The median TTD in global health status score was 8.3 months for EVE (95% confidence interval [CI], 6.9-11.5) vs 7.3 months for PBO (95% CI, 5.6-10.4; P = .8386). The median TTD in the physical, emotional, and social function subscale scores showed no significant difference between arms. For example, median TTD in the physical function subscale score was 12.0 months (95% CI, 8.3-14.1) for EVE vs 12.5 months (95% CI, 8.3-20.9) for PBO (P = .4251), and median TTD in the emotional function subscale score was 15.2 months (95% CI, 9.2-17.3) for EVE vs 12.5 months (95% CI, 9.7-16.4) for PBO (P = .8140).

Conclusions: These analyses demonstrate that, despite increased frequency of adverse events observed with the addition of EVE to the standard treatment of vinorelbine and trastuzumab, overall and functional HRQoL scores were not negatively impacted in patients with trastuzumab-resistant, HER2+, advanced breast cancer.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-12-18.

Cetuximab and platinum-based chemoradio- or chemotherapy of patients with epidermal growth factor receptor expressing adenoid cystic carcinoma: a phase II trial

Background:

Epidermal growth factor receptor (EGFR) is highly expressed in adenoid cystic carcinoma (ACC). The efficacy and toxicity of cetuximab with concomitant platinum-based chemoradio- or chemotherapy in patients with locally advanced or metastatic ACC, respectively, was evaluated.

Methods:

Eligible patients (9 with locally advanced tumour and 12 with metastases) had positive tumour EGFR expression. The cetuximab loading dose (400 mg m⁻²) was followed by 250 mg m⁻² per week. Locally advanced tumours were irradiated (mean dose 65 Gy) and treated with concomitant cisplatin (75 mg m⁻², intravenously). Patients with metastases received concomitant cisplatin and 5-fluorouracil (4 × 1000 mg m⁻²).

Results:

For patients with locally advanced disease (median follow-up: 52 months), the median progression-free survival (PFS) was 64 months and the 2-year overall survival (OS) rate was 100%. For patients with metastases (median follow-up: 72 months), the median PFS and OS were 13 and 24 months, respectively. In both groups the objective response rate was >40%. Skin rash, in-field dermatitis, mucositis and vomiting were the most frequent grade 3/4 adverse events.

Conclusion:

In this single-arm study, the efficacy of cetuximab plus chemoradio- or chemotherapy appeared favourable as compared with historical controls. All side effects were manageable and did not hamper the treatment.

Adjuvant pegylated liposomal doxorubicin for older women with endocrine nonresponsive breast cancer who are NOT suitable for a "standard chemotherapy regimen": the CASA randomized trial

There is no optimal treatment for breast cancers lacking estrogen (ER) and progesterone (PgR) receptors in elderly women with co-morbidities that prevent use of "standard chemotherapy regimens" such as AC or CMF. The CASA trial studied pegylated liposomal doxorubicin (PLD) and low dose, metronomic cyclophosphamide + methotrexate (CM) for older (>65), vulnerable women with operable, ER and PgR-negative breast cancer. After two years the trial closed early, due to slow and inadequate accrual, with 77 patients (38:PLD, 36:CM, 3:nil). Sixty-eight percent completed PLD; 83% completed CM (both 16 weeks). Patients on PLD reported worse quality of life, cognitive and physical functioning than non-PLD regimens (primarily CM). At a median follow-up of 42 months, 81% of randomized patients remained free of any breast cancer recurrence. Based on our limited experience, PLD and CM may be reasonable options for further study for elderly vulnerable patients with endocrine nonresponsive breast cancer.

CNS relapses in patients with HER2-positive early breast cancer who have and have not received adjuvant trastuzumab: a retrospective substudy of the HERA trial (BIG 1-01)

BACKGROUND

Several randomised trials have confirmed the benefit of adjuvant trastuzumab for patients with HER2-positive early breast cancer. However, concern has been expressed that adjuvant trastuzumab might be associated with an increased frequency of CNS relapses. We assessed the frequency and course of CNS relapses, either as first event or at any time, using data from the HERA trial.

METHODS

We estimated the cumulative incidence of first disease-free survival (DFS) events in the CNS versus other sites by competing risks analysis in patients with HER2-positive early breast cancer who had been randomly assigned to receive 1 year of trastuzumab or to observation in the HERA trial after a median follow-up of 4 years (IQR 3·5-4·8). To obtain further information about CNS relapse at any time before death, we circulated a data collection form to investigators to obtain standardised information about CNS events that occurred in all patients who had died before July, 2009. We estimated the cumulative incidence of CNS relapse at any time with a competing risks analysis.

RESULTS

Of 3401 patients who had been assigned to receive 1 year of trastuzumab or to observation, 69 (2%) had a CNS relapse as first DFS event and 747 (22%) had a first DFS event not in the CNS. The frequency of CNS relapses as first DFS event did not differ between the group given 1 year of trastuzumab (37 [2%] of 1703 patients) and the observation group (32 [2%] of 1698; p=0·55 [Gray's test]). 481 data collection forms were distributed, of which 413 (86%) were returned. The proportion of patients who had died and experienced a CNS relapse was numerically higher in the observation group (129 [57%] of 227) than in the group given trastuzumab for 1 year (88 [47%] of 186; p=0·06 [Gray's test]). Most CNS relapses were symptomatic (189 [87%] of 217).

CONCLUSION

Adjuvant trastuzumab does not increase the risk of CNS relapse in patients with HER2-positive early breast cancer.

FUNDING

None.