Adjuvant abemaciclib combined with endocrine therapy for high-risk early breast cancer: updated efficacy and Ki-67 analysis from the monarchE study

BACKGROUND

Adjuvant abemaciclib combined with endocrine therapy (ET) previously demonstrated clinically meaningful improvement in invasive disease-free survival (IDFS) and distant relapse-free survival (DRFS) in hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, high-risk early breast cancer at the second interim analysis, however follow-up was limited. Here, we present results of the prespecified primary outcome analysis and an additional follow-up analysis.

PATIENTS AND METHODS

This global, phase III, open-label trial randomized (1 : 1) 5637 patients to adjuvant ET for ≥5 years ± abemaciclib for 2 years. Cohort 1 enrolled patients with ≥4 positive axillary lymph nodes (ALNs), or 1-3 positive ALNs and either grade 3 disease or tumor ≥5 cm. Cohort 2 enrolled patients with 1-3 positive ALNs and centrally determined high Ki-67 index (≥20%). The primary endpoint was IDFS in the intent-to-treat population (cohorts 1 and 2). Secondary endpoints were IDFS in patients with high Ki-67, DRFS, overall survival, and safety.

RESULTS

At the primary outcome analysis, with 19 months median follow-up time, abemaciclib + ET resulted in a 29% reduction in the risk of developing an IDFS event [hazard ratio (HR) = 0.71, 95% confidence interval (CI) 0.58-0.87; nominal P = 0.0009]. At the additional follow-up analysis, with 27 months median follow-up and 90% of patients off treatment, IDFS (HR = 0.70, 95% CI 0.59-0.82; nominal P < 0.0001) and DRFS (HR = 0.69, 95% CI 0.57-0.83; nominal P < 0.0001) benefit was maintained. The absolute improvements in 3-year IDFS and DRFS rates were 5.4% and 4.2%, respectively. Whereas Ki-67 index was prognostic, abemaciclib benefit was consistent regardless of Ki-67 index. Safety data were consistent with the known abemaciclib risk profile.

CONCLUSION

Abemaciclib + ET significantly improved IDFS in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative, node-positive, high-risk early breast cancer, with an acceptable safety profile. Ki-67 index was prognostic, but abemaciclib benefit was observed regardless of Ki-67 index. Overall, the robust treatment benefit of abemaciclib extended beyond the 2-year treatment period.

Primary surgery versus no surgery in synchronous metastatic breast cancer: patient-reported quality-of-life outcomes of the prospective randomized multicenter ABCSG-28 Posytive Trial

BACKGROUND

The ABCSG-28 trial compared primary surgery followed by systemic therapy versus primary systemic therapy without surgery in patients with de novo stage IV BC. The present report describes QoL results of this trial.

METHODS

Ninety patients with primary operable MBC were randomised to surgery of the primary tumor followed by systemic therapy or to primary systemic therapy without surgery. QoL analyses covering the results at baseline, 6,12,18 and 24 months follow up of 79 (88%) patients, was assessed with the EORTC QLQ-C30 and QLQ-BR23 questionnaires.

RESULTS

There were no statistically significant differences in any of the scales of the QLQ-C30 and QLQ-BR23 questionnaires between the two groups over the time. Baseline global health status and physical functioning were predictors for OS (patients with a higher score lived longer (p=0.0250, p=0.0225; p=0.0355, p=0.0355)). Global health status, social functioning scale, breast symptoms and future perspective were predictors for longer TTPd (p=0.0244; p=0.0140, p=0.020; p=0.0438, p=0.0123). Patients in both arms reported significant improvement on the emotional functioning scale. Cognitive functioning decreased over time in both groups. Younger women had clinically relevant better physical and sexual functioning scores (p=0.039 and 0.024).

CONCLUSION

Primary surgery does not improve nor alter QoL of patients with de novo stage IV BC. Global health status and physical functioning were predictors for OS and could be use as additional marker for prediction of OS and TTTd in patients with de novo stage IV BC.

TRIAL REGISTRATION

The trial is registered on clinicaltrial.gov (NCT01015625, date of registration:18/11/2009).

Dose tailoring of adjuvant chemotherapy for breast cancer based on hematologic toxicities: further results from the prospective PANTHER study with focus on obese patients

Background

Adjuvant chemotherapy (ACT) for breast cancer improves relapse-free survival (BCRFS) and overall survival. Differences in terms of efficacy and toxicity could partly be explained by the significant interpatient variability in pharmacokinetics which cannot be captured by dosing according to body surface area. Consequently, tailored dosing was prospectively evaluated in the PANTHER trial.

Patients and methods

PANTHER is a multicenter, open-label, randomized phase III trial which compared tailored, dose-dense (DD) epirubicin/cyclophosphamide (E/C) and tailored docetaxel (D) (tDD) with standard interval 5-fluorouracil/E/C and D. The primary end point was BCRFS and the primary efficacy analysis has been previously published. In this secondary analysis, we aimed to retrospectively explore the concept of dose tailoring. Our two hypotheses were that BCRFS would not vary depending on the cumulative administered epirubicin dose; and that dose tailoring would lead to appropriate dosing and improved outcomes for obese patients, who are known to have worse prognosis and increased toxicity after DD ACT.

Results

Patients treated with tDD had similar BCRFS regardless of the cumulative epirubicin dose (P = 0.495), while obese patients in this group [body mass index (BMI) ≥30] had improved BCRFS compared with nonobese ones (BMI <30) [hazard ratio (HR) = 0.51, 95% confidence interval (CI) 0.30-0.89, P = 0.02]. Moreover, tDD was associated with improved BCRFS compared with standard treatment only in obese patients (HR = 0.49, 95% CI 0.26-0.90, P = 0.022) but not in nonobese ones (HR = 0.79, 95% CI 0.60-1.04, P = 0.089). The differences were not formally statistically significant (P for interaction 0.175). There were no differences in terms of toxicity across the epirubicin dose levels or the BMI groups.

Conclusions

Dose tailoring is a feasible strategy that can potentially improve outcomes in obese patients without increasing toxicity and should be pursued in further clinical studies.

ClinicalTrials.gov identifier

NCT00798070.

Impact of Surgical Margins in Breast Cancer After Preoperative Systemic Chemotherapy on Local Recurrence and Survival

Background

While “no tumour on ink” is an accepted margin width for R₀ resection in primary surgery, it’s unclear if it’s oncologically safe after neoadjuvant chemotherapy (NAC). Only limited data demonstrate that surgery within new margins in cases of a pathological complete response (pCR) is safe. We therefore investigated the influence of different margins and pCR on local recurrence and survival rates after NAC.

Methods

We retrospectively analysed data of 406 women with invasive breast cancer, treated with NAC and breast-conserving therapy between 1994 and 2014 in two certified Austrian breast health centres. We compared R ≤ 1 mm, R > 1 mm and RX (pCR) for local recurrence-free survival (LRFS), disease-free survival (DFS) and overall survival (OS).

Results

After a median follow-up of 84.3 months, the 5-year LRFS (R ≤ 1 mm: 94.2%, R > 1 mm: 90.6%, RX: 95.0%; p = 0.940), the 5-year DFS (R ≤ 1 mm: 71.9%, R > 1 mm: 74.1%, RX: 87.2%; p = 0.245) and the 5-year OS (R ≤ 1 mm: 85.1%, R > 1 mm: 88.0%, RX: 96.4%; p = 0.236) did not differ significantly between narrow, wide, nor RX resections. Regarding DFS and OS, a negative nodal status reduced the hazard ratio significantly.

Conclusion

There is no significant difference in LRFS, DFS and OS comparing close, wide or unknown margins after pCR. We suggest that resection in new margins after NAC is safe according to “no tumour on ink”. Resection of the clipped area in cases of pCR is emphasized.

Abstract P1-17-05: The impact of clinical risk assessment versus PAM-50 ROR score on prognosis and therapeutic decision making in patients with hormone-receptor positive early stage breast cancer

Background: Therapeutic recommendations for adjuvant treatment of hormone-receptor positive breast cancer patients depend on the individual recurrence risk. A number of genomic assays introduced to achieve this goal, but it's still questioned if they actually offer superior risk assessment compared to traditional risk evaluation by experienced clinicians. This study was designed to compare the prognostic accuracy of PAM-50 to clinical judgment.

Methods: Based on the real data of a large adjuvant trial cohort (ABCSG-8, postmenopausal HR positive breast cancer patients), we created online-questionnaires including demographic, histological, and local-therapy details, with and without results of PAM50 ROR score. Out of 14 international breast cancer experts asked for individual patient's risk evaluation (low, intermediate, high) and therapy recommendations, 9 completed the questionnaire.

Patient data were described by Kaplan-Meier estimates of distant disease free survival (DDFS) stratified by risk group. Cox regression models were compared using the Akaike Information Criterion (AIC).

Results: 10 years DDFS and hazard ratios for distant recurrences stratified by risk-group as estimated giving in Table 1:

10 years DDFS and hazard ratios for distant recurrences stratified by risk-group as estimated Low riskIntermediate riskHigh risk n (%)10y DDFS,%(95%CI)n (%)10y DDFS,%(95%CI)n (%)10y DDFS, %(95%CI)  HR(95% CI) HR(95% CI) HR(95% CI)Clinical only: AIC 817.6269 (43)93.0(89.8-96.2)289 (46)89.7(85.9-93.5)73 (11)76.6(66.1-87.1)  0.68(0.39,1.20) 1 2.57(1.41,4.65)PAM50 ROR: AIC 804.8241 (34)96.5(93.1-99.1)210 (33)89.2(84.7-93.7)207 (33)82.5(76.9-88.2)  0.27(0.11,0.62) 1 1.66(0.99,2.78)Combined: AIC 813.4232 (37)95.7(93.0-98.5)282 (45)87.8(83.7-92.0)117 (18)81.7(74.2-89.2)  0.42(0.22,0.84) 1 1.90(1.11,3.24)

Adding genomic information to clinical risk factors leads to escalation of therapeutic recommendations (i.e. additional chemotherapy, extended adjuvant endocrine) in 20% of patients, and de-escalation in 13% of patients.

Conclusions: Clinical judgment accurately identified the patients at high risk of relapse, but was clearly inferior to multi-genomic testing using the PAM-50 ROR score in differentiating low from intermediate risk. Particularly when avoiding unnecessary escalated therapy is the strategic goal, the addition of PAM-50 testing to clinical judgment offers improved accuracy in predicting low vs. intermediate risk of breast cancer recurrence.

Citation Format: Devyatko Y, Filipits M, Greil R, Balic M, Bago-Horvath Z, Singer C, Fitzal F, Steger G, Gray B, Ferree S, Fesl C, Soelkner L, von Minckwitz G, Gnant M. The impact of clinical risk assessment versus PAM-50 ROR score on prognosis and therapeutic decision making in patients with hormone-receptor positive early stage breast cancer [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 P1-17-05.

Abstract P6-21-02: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Minichsdorfer C, Bergen E, Steger GG, Pfeiler G, Frantal S, Greil R, Fohler H, Egle D, Balic M, Fitzal F, Wette V, Exner R, Bartsch RA, Gnant M. Withdrawn [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 P6-21-02.

Metastatic or locally advanced breast cancer patients: towards an expert consensus on nab-paclitaxel treatment in HER2-negative tumours-the MACBETH project

INTRODUCTION

Despite the large use of nab-paclitaxel as a treatment option in metastatic breast cancer (MBC) across different countries, no definitive data are available in particular clinical situations.

AREAS COVERED

Efficacy, safety and schedule issues concerning available literature on nab-paclitaxel in advanced breast cancer and in specific subgroups of patients have been discussed and voted during an International Expert Meeting. Ten expert specialists in oncology, with extensive clinical experience on Nab-P and publications in the field of MBC have been identified. Six scientific areas of interest have been covered, generating 13 specific Statements for Nab-P, after literature review. For efficacy issues, a summary of research quality was performed adopting the GRADE algorithm for evidence scoring. The panel members were invited to express their opinion on the statements, in case of disagreement all the controversial opinions and the relative motivations have been made public.

EXPERT OPINION

Consensus was reached in 30.8% of the Nab-P statements, mainly those regarding safety issues, whereas ones regarding efficacy and schedule still remain controversial areas, requiring further data originated by the literature.

Propagation and some physiological effects of Citrus bark cracking viroid and Apple fruit crinkle viroid in multiple infected hop (Humulus lupulus L.)

The hop metabolome important for the brewing industry and for medical purposes is endangered worldwide due to multiple viroid infections affecting hop physiology. Combinatorial biolistic hop inoculation with Citrus bark cracking viroid (CBCVd), Apple fruit crinkle viroid (AFCVd), Hop latent viroid, and Hop stunt viroid (HSVd) showed a low CBCVd compatibility with HSVd, while all other viroid combinations were highly compatible. Unlike to other viroids, single CBCVd propagation showed a significant excess of (-) over (+) strands in hop, tomato, and Nicotiana benthamiana, but not in citruses. Inoculation of hop with all viroids led to multiple infections with unstable viroid levels in individual plants in the pre- and post-dormancy periods, and to high plant mortality and morphological disorders. Hop isolates of CBCVd and AFCVd were highly stable, only minor quasispecies were detected. CBCVd caused a strong suppression of some crucial mRNAs related to the hop prenylflavonoid biosynthesis pathway, while AFCVd-caused effects were moderate. According to mRNA degradome analysis, this suppression was not caused by a direct viroid-specific small RNA-mediated degradation. CBCVd infection led to a strong induction of two hop transcription factors from WRKY family and to a disbalance of WRKY/WDR1 complexes important for activation of lupulin genes.

Final efficacy and updated safety results of the randomized phase III BEATRICE trial evaluating adjuvant bevacizumab-containing therapy in triple-negative early breast cancer

Background

The purpose of this analysis was to assess the long-term impact of adding bevacizumab to adjuvant chemotherapy for early triple-negative breast cancer (TNBC).

Methods

Patients eligible for the open-label randomized phase III BEATRICE trial had centrally confirmed triple-negative operable primary invasive breast cancer (pT1a-pT3). Investigators selected anthracycline- and/or taxane-based chemotherapy for each patient. After definitive surgery, patients were randomized 1:1 to receive ≥4 cycles of chemotherapy alone or with 1 year of bevacizumab (5 mg/kg/week equivalent). Stratification factors were nodal status, selected chemotherapy, hormone receptor status, and type of surgery. The primary end point was invasive disease-free survival (IDFS; previously reported). Secondary outcome measures included overall survival (OS) and safety.

Results

After 56 months' median follow-up, 293 of 2591 randomized patients had died. There was no statistically significant difference in OS between treatment arms in either the total population (hazard ratio 0.93, 95% confidence interval [CI] 0.74-1.17; P = 0.52) or pre-specified subgroups. The 5-year OS rate was 88% (95% CI 86-90%) in both treatment arms. Updated IDFS results were consistent with the primary IDFS analysis. Five-year IDFS rates were 77% (95% CI 75-79%) with chemotherapy alone versus 80% (95% CI 77-82%) with bevacizumab. From 18 months after first study dose to study end, new grade ≥3 adverse events occurred in 4.6% and 4.5% of patients in the two arms, respectively.

Conclusion

Final OS results showed no significant benefit from bevacizumab therapy for early TNBC. Late-onset toxicities were rare in both groups. Five-year OS and IDFS rates suggest that the prognosis for patients with TNBC is better than previously thought.

ClinicalTrials.gov

NCT00528567.

Abstract P1-09-10: Pathological complete response to neoadjuvant trastuzumab is dependent on HER2/CEP17 ratio in HER2-amplified early breast cancer

Purpose To evaluate whether pathological complete response to neoadjuvant trastuzumab is dependent on the level of HER2 amplification.

Patients and Methods 114 women with HER2-overexpressing early breast cancer who had received neo-adjuvant trastuzumab in the prospective ABCSG-24 and ABCSG-32 trials, and for whom the HER2/CEP17 ratio was available, were included in this analysis. The ratio was correlated with tumor response as measured by the three most commonly used definitions of pathological complete response: ypT0 ypN0, ypT0/is ypN0, and ypT0/is.

Results In trastuzumab-treated patients, ypT0 pN0 was achieved in 69.0% of patients with a HER2/CEP17 ratio of &gt;6, but only in 30.4% of tumors with a ratio of ≤6 (p=0.001, Chi Square test). When pCR was defined by ypT0/is pN0 or by ypTis, 75.9% and 82.8% of tumors with a high ratio had a complete remission, while only 39.1%, and 38.3% with a low ratio achieved a pCR (p=0.002 and p&lt;0.001, respectively). Logistic regression revealed that tumors with a higher HER2/CEP17 ratio had a significantly higher probability to achieve ypT0 ypN0 (OR: 5.08, 95% CI 1.86-13.90; p=0.002) than tumors with a low ratio, while none of the other clinicopathological parameters was predictive of pCR. The association between high HER2 amplification and pCR was almost exclusively confined to HR positive tumors (62.5% vs. 24.0%, 75.0% vs. 28.0%, and 87.5% vs. 28.0%, for ypT0 ypN0, ypT0/is ypN0, and ypT0/is; p=0.014, p=0.005, and p&lt;0.001), and was largely absent in HR negative tumors.

Conclusion A HER2/CEP17 ratio of &gt;6 in the pre-therapeutic tumor biopsy is associated with a significantly higher pCR rate particularly in HER2 / HR co-positive tumors, and can be used to predict outcome before neoadjuvant trastuzumab is initiated.

Citation Format: Singer CF, Tan YY, Fitzal F, Steger GG, Egle D, Reiner A, Rudas M, Gruber C, Bartsch R, Fridrik M, Seifert M, Exner R, Balic M, Bago-Horvath Z, Filipits M, Gnant M, For the Austrian Breast and Colorectal Cancer Study Group. Pathological complete response to neoadjuvant trastuzumab is dependent on HER2/CEP17 ratio in HER2-amplified 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 P1-09-10.

Prognostic impact of breast cancer subtypes in elderly patients

We aimed to analyse the impact of breast cancer (BC) subtypes on the clinical course of disease with special emphasis on the occurrence of brain metastases (BM) and outcome in an elderly BC population. A total number of 706 patients ≥65 years receiving treatment for BC from 2007 to 2011 were identified from a BC database. 62 patients diagnosed with DCIS and 73 patients with incomplete datasets were excluded, leaving 571 patients for this analysis. Patient characteristics, biological tumour subtypes, and clinical outcome including overall survival (OS) were obtained by retrospective chart review. 380/571 (66, 5 %) patients aged 65–74 years were grouped among the young-old, 182/571 (31.9 %) patients aged 75–84 years among the old–old, and 29/571 (5.1 %) patients aged ≥85 years among the oldest-old. 392/571 (68.8 %) patients presented with luminal BC, 119/571 (20.8 %) with HER2-positive, and 59/571 (10.3 %) with triple-negative BC (TNBC). At 38 months median follow-up, 115/571 (20.1 %) patients presented with distant recurrence. A higher recurrence rate was observed in the HER2-positive subtype (43/119 (36.1 %)), as compared to TNBC (15/59 (25.4 %)) and luminal BC (57/392 (14.5 %); p < 0.001). BM were detected at a significantly higher rate in HER2-positive BC patients (9/119 (7.6 %)), as compared to TNBC (2/59 (3.4 %)) and luminal BC patients (6/392 (1.5 %); p = 0.003). Diagnosis of metastatic disease (HR 7.7; 95 % CI 5.2–11.4; p < 0.001) as well as development of BM (HR 3.5; 95 % CI 1.9–6.4; p < 0.001) had a significantly negative impact on OS in a time-dependent covariate cox regression model. In contrast to younger BC patients, outcome in this large cohort of elderly patients suggests that HER2-positive disease—not TNBC—featured the most aggressive clinical course with the highest rates of metastatic spread and BM. In-depth analysis regarding a potentially distinct biology of TNBC in elderly is therefore warranted.

Abstract S1-01: Analysis of molecular prognostic factors associated with tumor immune and stromal microenvironment in BEATRICE, an open-label phase 3 trial in early triple-negative breast cancer (eTNBC)

Background: TNBC is a mutationally complex heterogeneous breast cancer subtype. In BEATRICE, adding bevacizumab to standard adjuvant chemotherapy for eTNBC improved neither invasive disease-free survival (IDFS; primary endpoint) nor overall survival (OS) [Cameron 2013; Bell SABCS 2014]. We explored prognostic effects of tumor-associated immune and stromal gene signatures.

Methods: Gene expression (RNA) was assessed in pretreatment archival tumor tissue using an 800-gene nanostring platform. Given the low event rates and lack of bevacizumab effect in BEATRICE, treatment arms were pooled. The biomarker-evaluable population (BEP; all patients with an evaluable biomarker sample and ≥1 postbaseline efficacy assessment) was dichotomized using median gene expression level as the cutoff. Prognostic associations between IDFS/OS and prespecified candidate gene sets/de novo identified clusters were assessed using univariate Cox proportional hazards models.

Results: Baseline characteristics and efficacy were similar in the BEP (988/2591 randomized pts; 38%) and the overall study population. In hierarchical cluster analysis based exclusively on immune gene expression, immune genes were enriched in 33% of samples, intermediate in 38%, and weak in 28%. Further characterization suggested differential prognostic value of distinct immune and stromal cell gene sets (Table). A significant prognostic effect for IDFS and OS was seen for CD8 effector T cell (Teff) and regulatory T cell (Treg) gene signatures, but not for the Teff:Treg ratio. A less pronounced positive prognostic effect was seen for other gene sets representing immune cells, including macrophages, CD4 T cells, and B cells (data not shown). Activated T helper (Th)-1 cell-derived chemokines and negative immune modulators of T cell activity (eg PD-L1) were highly prognostic for IDFS and OS. Both the cytokine IL-8 and ESM1 (target of VEGF-A pathway activation) were associated with worse IDFS and OS. No association was seen between outcome and markers for classic microvasculature (CD31, CD34), cancer-associated fibroblasts (FAP, BGN, DCN), VEGF-A, or VEGF-C.

 IDFSOSGene signatureHR (95% CI)Interaction p-valueHR (95% CI)Interaction p-valueTeff0.40 (0.28-0.57)7.2x10-70.29 (0.17-0.49)4.2x10-6Treg0.38 (0.26-0.54)1.6x10-70.23 (0.13-0.40)2.9x10-7Teff:Treg ratio0.80 (0.58-1.12)0.20.89 (0.57-1.39)0.6Th10.45 (0.31-0.64)8.1x10-60.43 (0.27-0.70)5.8x10-4PD-L10.42 (0.29-0.60)1.8x10-60.24 (0.14-0.41)3.4x10-7IL-81.48 (1.06-2.08)0.0221.89 (1.18-3.01)0.0076ESM11.73 (1.23-2.43)0.00172.22 (1.38-3.58)0.001

Conclusions: These molecular gene signature analyses in eTNBC confirm that markers of cytotoxic CD8 T cells are associated with good prognosis. This is the first report of a positive prognostic effect of regulatory T cell markers, immune checkpoint modulators, and macrophage-associated markers in the adjuvant TNBC setting. High VEGF-A activity, but not its expression, was associated with worse prognosis. The strong prognostic effect of immune checkpoint modulators suggests equilibrium between cytotoxic T cells and their inhibitors in eTNBC, supporting further exploration of immune checkpoint inhibitors in this therapeutic context.

Citation Format: Molinero L, Yu J, Li C, Deurloo R, Dent RA, Bell R, Brown J, Parmar M, Toi M, Suter T, Steger G, Pivot X, Mackey J, Jackisch C, Hall P, Hegde P, Bais C, Cameron D. Analysis of molecular prognostic factors associated with tumor immune and stromal microenvironment in BEATRICE, an open-label phase 3 trial in early triple-negative breast cancer (eTNBC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr S1-01.

Abstract P2-08-17: Prognostic impact of breast cancer subtypes in elderly patients

Background

We aimed to analyze the impact of BC subtypes on the clinical course with special emphasis on the occurrence of brain metastases (BM) and outcome in an elderly breast cancer population.

Patients and Methods

571 patients ≥65 years receiving treatment for BC from 2007-2011 were identified from a BC database. BC subtypes and clinical characteristics including overall survival (OS) were obtained by chart review. Statistical analysis was performed using the Chi Square test, the log rank test and time depended covariate cox regression model as appropriate.

Results

Three-hundred-eighty/571 (63%) were grouped among the young-old (65-74 years), 182/571 (31.9%) among the old-old (75-84 years), and 29/571 (5,1%) among the oldest-old (≥85 years). 392/571 (68.8%) patients presented with luminal BC, 119/571 (20.8%) with HER2 positive and 59/571 (10.3%) with triple negative BC. After a median follow up of 38 months (range 0-204), 115/571 (20.1%) patients presented with metastatic recurrence. Highest recurrence rate was observed in HER2 positive BC patients (43/119 (36.1%)), followed by triple negative (15/59 (25.4%) and luminal BC (57/392 (14.5%); p&lt;0.001; Chi Square test). BM occurred significantly more frequently in HER2 positive BC patients (9/119 (7.6%) compared to triple negative (2/59 (3.4%) and luminal BC patients (6/392 (1.5%); p=0.003; Chi Square test). Occurrence of metastases (HR 7.7; 95% CI 5.2-11.4; p&lt;0.001) as well as development of BM (HR 3.5; 95% CI 1.9-6.4; p&lt;0.001) had a significant impact on OS prognosis as entered in a time depended covariate cox regression model.

Conclusions

In contrast to younger BC patients, HER2 positive BC subtype and not triple negative BC subtype was linked to the most aggressive clinical course including the development of metastatic disease and BM in our elderly cohort.

Citation Format: Bergen ES, Tichy C, Berghoff AS, Rudas M, Dubsky P, Bago-Horvath Z, Mader RM, Gnant M, Dieckmann K, Zielinski CC, Steger GG, Preusser M, Bartsch R. Prognostic impact of breast cancer subtypes in elderly patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-08-17.

Zoledronic acid combined with adjuvant endocrine therapy of tamoxifen versus anastrozol plus ovarian function suppression in premenopausal early breast cancer: final analysis of the Austrian Breast and Colorectal Cancer Study Group Trial 12

BACKGROUND

Zoledronic acid (ZOL) plus adjuvant endocrine therapy significantly improved disease-free survival (DFS) at 48- and 62-month follow-up in the ABCSG-12 trial. We present efficacy results of a final additional analysis after 94.4 months.

PATIENTS AND METHODS

Patients were premenopausal women who had undergone primary surgery for stage I/II estrogen-receptor-positive and/or progesterone-receptor-positive breast cancer with <10 positive lymph nodes, and were scheduled for standard goserelin therapy. All 1803 patients received goserelin (3.6 mg every 28 days) and were randomized to tamoxifen (20 mg/days) or anastrozole (1 mg/days), both with or without ZOL (4 mg every 6 months) for 3 years. The primary end point was DFS; recurrence-free survival and overall survival (OS) were secondary end points.

RESULTS

After 94.4-month median follow-up (range, 0-114 months), relative risks of disease progression [hazard ratio (HR) = 0.77; 95% confidence interval (CI) 0.60-0.99; P = 0.042] and of death (HR = 0.66; 95% CI 0.43-1.02; P = 0.064) are still reduced by ZOL although no longer significant at the predefined significance level. Overall, 251 DFS events and 86 deaths were reported. Absolute risk reductions with ZOL were 3.4% for DFS and 2.2% for OS. There was no DFS difference between tamoxifen alone versus anastrozole alone, but there was a pronounced higher risk of death for anastrozole-treated patients (HR = 1.63; 95% CI 1.05-1.45; P = 0.030). Treatments were generally well tolerated, with no reports of renal failure or osteonecrosis of the jaw.

CONCLUSION

These final results from ABCSG 12 suggest that twice-yearly ZOL enhances the efficacy of adjuvant endocrine treatment, and this benefit is maintained long-term.

CLINICALTRIALSGOV

NCT00295646 (http://www.clinicaltrials.gov/ct2/results?term=00295646).

Epirubicin and docetaxel with or without capecitabine as neoadjuvant treatment for early breast cancer: final results of a randomized phase III study (ABCSG-24)

BACKGROUND

This randomized phase III trial compared pathologic complete response (pCR) rates of early breast cancer (EBC) following neoadjuvant epirubicin-docetaxel (ED)±capecitabine (C), and evaluated the addition of trastuzumab in HER2-positive tumors.

PATIENTS AND METHODS

Patients with invasive breast cancer (except T4d) were randomly assigned to receive six 3-weekly cycles of ED (both 75 mg/m2)±C (1000 mg/m2, twice daily, days 1-14). Patients with HER2-positive disease were further randomized to receive trastuzumab (8 mg/kg, then 6 mg/kg every 3 weeks) or not. Primary end point: pCR rate at the time of surgery.

RESULTS

Five hundred thirty-six patients were randomized to ED (n=266) or EDC (n=270); 93 patients were further randomized to trastuzumab (n=44) or not (n=49). pCR rate was significantly increased with EDC (23.0% versus 15.4% ED, P=0.027), and nonsignificantly further increased with trastuzumab (38.6% EDC versus 26.5% ED, P=0.212). Rates of axillary node involvement at surgery and breast conservation were improved with EDC versus ED, but not significantly; the addition of trastuzumab had no further impact. Hormone receptor status, tumor size, grade, and C (all P≤0.035) were independent prognostic factors for pCR. Trastuzumab added to ED±C significantly increased the number of serious adverse events (35 versus 18; P=0.020), mainly due to infusion-related reactions.

CONCLUSION

These findings show that the integration of C into a neoadjuvant taxane-/anthracycline-based regimen is a feasible, safe, and effective treatment option, with incorporation of trastuzumab in HER2-positive disease.

CLINICAL TRIAL NUMBER

NCT00309556, www.clinicaltrials.gov.

Predicting distant recurrence in receptor-positive breast cancer patients with limited clinicopathological risk: using the PAM50 Risk of Recurrence score in 1478 postmenopausal patients of the ABCSG-8 trial treated with adjuvant endocrine therapy alone

BACKGROUND

PAM50 is a 50-gene test that is designed to identify intrinsic breast cancer subtypes and generate a Risk of Recurrence (ROR) score. It has been developed to be carried out in qualified routine hospital pathology laboratories.

PATIENTS AND METHODS

One thousand four hundred seventy-eight postmenopausal women with estrogen receptor (ER)+ early breast cancer (EBC) treated with tamoxifen or tamoxifen followed by anastrozole from the prospective randomized ABCSG-8 trial were entered into this study. Patients did not receive adjuvant chemotherapy. RNA was extracted from paraffin blocks and analyzed using the PAM50 test. Both intrinsic subtype (luminal A/B, HER2-enriched, basal-like) and ROR score were calculated. The primary analysis was designed to test whether the continuous ROR score adds prognostic value in predicting distant recurrence (DR) over and above standard clinical variables.

RESULTS

In all tested subgroups, ROR score significantly adds prognostic information to the clinical predictor (P<0.0001). PAM50 assigns an intrinsic subtype to all cases, and the luminal A cohort had a significantly lower ROR at 10 years compared with Luminal B (P<0.0001). Significant and clinically relevant discrimination between low- and high-risk groups occurred also within all tested subgroups.

CONCLUSION(S)

The results of the primary analysis, in combination with recently published results from the ATAC trial, constitute Level 1 evidence for clinical validity of the PAM50 test for predicting the risk of DR in postmenopausal women with ER+ EBC. A 10-year metastasis risk of <3.5% in the ROR low category makes it unlikely that additional chemotherapy would improve this outcome-this finding could help to avoid unwarranted overtreatment.

CLINICAL TRIAL NUMBER

ABCSG 8: NCT00291759.

Abstract P1-08-40: BRCA-1 promotor methylation and p53 mutation in triple-negative breast cancer patients refrectory to taxane-based neoadjuvant chemotherapy

Introduction

Triple-negative breast cancer (TNBC) without pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) is associated with high risk of disease recurrence. In ABCSG trials 14 and 24, concomitant epirubicin plus docetaxel (+/- capecitabine) was used as NAC regimen; patients (pts) without pCR routinely received another 4-8 cycles of adjuvant CMF.

Tumours harbouring BRCA-1 germline mutations are apparently less responsive to taxane-based chemotherapy, while sensitivity to DNA-damaging agents is retained. In sporadic TNBC, BRCA-1 promotor methylation is frequently observed; this may also result in an impaired activity of genetic repair mechanisms. Therefore, we investigated the effect of adjuvant CMF as salvage therapy in pts with or without BRCA-1 promotor methylation who did not achieve pCR to taxane-based (cyclophosphamide-free) NAC. Moreover, the predictive role of TP53 mutations was investigated in these tumours.

Methods

All pts with TNBC refractory to taxane-based NAC who received adjuvant CMF were included.

DNA was extracted from formalin-fixed paraffin-embedded tissue samples with the Qiagen DNA FFPE Tissue Kit® and purified. For determining BRCA1 promoter methylation status, DNA was bisulfite-treated; the TaqMan® assay was used in order to perform a quantitative methylation-specific PCR. DNA quantity was normalized using Actin-b.

For the investigation of TP53 mutations in exons 4-9, purified DNA was PCR amplified, sequenced by Sanger sequencing and results were analyzed with SeqScape® software version 2.7. Mutations were validated using the IARC p53 database.

Results

Twenty-four pts, median age 47 years, were available for this analysis. In 10/24 pts (41.7%), a BRCA-1 promotor methylation was detected; TP53 mutations were observed in 16/24 pts (66.7%). At a median follow-up of 27.5 months, 2/10 pts (20%) with BRCA-1 promotor metyhlation had a disease-free survival (DFS) event, as compared to 9/14 (64.3%) in the non-methylated group (p = 0.0472; Fisher's exact test). Kaplan Meier estimation of disease-free survival (DFS) in the non-methylated group was 16 months (95% CI 0.0-41.73) and was not reached in the methylated group (n.s.). TP53 mutation was neither associated with increased risk of disease recurrence nor with DFS. No correlation was observed between BRCA-1 promotor methylation and TP53 mutation; still, all methylated samples were exclusively affected be missense and nonsense mutations.

Conclusions

Adjuvant CMF is of limited activity in TNBC refractory to taxane-based NAC. Still, in breast cancer harbouring BRCA-1 promotor methylation, a significant decrease of DFS events was observed. TP53 mutation status on the other hand, was not associated with outcome; while no correlation was found between BRCA-1 promotor methylation and TP53 mutation status, we only observed missense and non-sense mutations in methylated samples.

In conclusion, tumours harbouring BRCA-1 promotor methylation are apparently sensitive to DNA damage caused by cyclophosphamide. Further clinical validation of this concept is warranted.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-08-40.

The predictive impact of body mass index on the efficacy of extended adjuvant endocrine treatment with anastrozole in postmenopausal patients with breast cancer: an analysis of the randomised ABCSG-6a trial

BACKGROUND

We investigated whether body mass index (BMI) can be used as a predictive parameter indicating patients who benefit from extended aromatase inhibitor (AI) treatment.

METHODS

The ABCSG-6a trial re-randomised event-free postmenopausal hormone receptor-positive patients from the ABCSG-6 trial to receive either 3 additional years of endocrine therapy using anastrozole vs nil. In this retrospective analysis, we investigated the prognostic and predictive impact of BMI on disease outcome and safety.

RESULTS

In all, 634 patients (177 normal weight, 307 overweight, and 150 obese) patients were included in this analysis. Normal weight patients with additional 3 years of anastrozole halved their risk of disease recurrence (disease-free survival (DFS) HR 0.48; P=0.02) and death (HR 0.45; P=0.06) and had only a fifth of the risk of distant metastases (HR 0.22; P=0.05) compared with normal weight patients without any further treatment. In contrast, overweight+obese patients derived no benefit from additional 3 years of anastrozole (DFS HR 0.93; P=0.68; distant recurrence-free survival HR 0.91; P=0.78; and OS HR 0.9; P=0.68). The possible predictive impact of BMI on extended endocrine treatment could be strengthened by a Cox regression interaction model between BMI and treatment (P=0.07).

CONCLUSION

Body mass index may be used to predict outcome benefit of extended AI treatment in patients with receptor-positive breast cancer.

Brain-only metastatic breast cancer is a distinct clinical entity characterised by favourable median overall survival time and a high rate of long-term survivors

BACKGROUND

The clinical course of breast cancer patients with brain metastases (BM) as only metastatic site (brain-only metastatic breast cancer (BO-MBC)) has been insufficiently explored.

METHODS

All breast cancer patients with BM treated at our institution between 1990 and 2011 were identified. For each patient, full information on follow-up and administered therapies was mandatory for inclusion. Oestrogen receptor, progesterone receptor and Her2 status were determined according to standard protocols. Statistical analyses including computation of survival probabilities was performed.

RESULTS

In total, 222 female patients (26% luminal; 47% Her2; 27% triple negative) with BM of MBC were included in this study. In all, 38/222 (17%) BM patients did not develop extracranial metastases (ECM) during their disease course and were classified as BO-MBC. Brain-only-MBC was not associated with breast cancer subtype or number of BM. The median overall survival of BO-MBC patients was 11 months (range 0-69) and was significantly longer than in patients with BM and ECM (6 months, range 0-104; P=0.007). In all, 7/38 (18%) BO-MBC patients had long-term survival of >3 years after diagnosis of BM and long-term survival was significantly more common in BO-MBC patients as compared with BM patients with ECM (P<0.001).

CONCLUSIONS

Brain-only metastatic behaviour occurs in around 17% of breast cancer with BM and is not associated with breast cancer subtype. Exploitation of all multimodal treatment options is warranted in BO-MBC patients, as these patients have favourable prognosis and long-term survival is not uncommon.

Phase IB study of the EpCAM antibody adecatumumab combined with docetaxel in patients with EpCAM-positive relapsed or refractory advanced-stage breast cancer

BACKGROUND

Targeted therapy options in HER2-negative breast cancer are limited. This open-label, multicenter phase IB dose-escalation trial was conducted to determine safety, tolerability, and antitumor activity of a combination of docetaxel (Taxotere) and increasing doses of adecatumumab, a human IgG1 antibody targeting epithelial cell adhesion molecule (EpCAM), in EpCAM-positive relapsed or primary refractory advanced-stage breast cancer.

PATIENTS AND METHODS

Patients pretreated with up to four prior chemotherapy regimens received increasing adecatumumab doses either every 3 weeks (q3w) or weekly (qw) combined with docetaxel (100 mg/m(2) q3w). Primary end points were safety and tolerability. Antitumor activity was evaluated according to RECIST. Clinical benefit was defined as complete or partial response or stable disease for ≥24 weeks.

RESULTS

Thirty-one evaluable patients were treated. Most adverse events were mild to moderate in severity. Neutropenia, leukocytopenia, lymphopenia, and diarrhea (dose-limiting) were the most frequent toxic effects. Maximum tolerated doses of adecatumumab given in combination with docetaxel were 550 mg/m(2) q3w and 360 mg/m(2) qw. Clinical benefit was observed in 44% of patients treated with q3w adecatumumab and docetaxel, increasing to 63% in patients with high EpCAM-expressing tumors.

CONCLUSION

Combination therapy of adecatumumab and docetaxel is safe, feasible, and potentially active in heavily pretreated advanced-stage breast cancer.

Safety results from a phase III study (TURANDOT trial by CECOG) of first-line bevacizumab in combination with capecitabine or paclitaxel for HER-2-negative locally recurrent or metastatic breast cancer

BACKGROUND

We report safety data from a randomised, phase III study (CECOG/BC.1.3.005) evaluating first-line bevacizumab plus paclitaxel or capecitabine for locally recurrent or metastatic breast cancer.

PATIENTS AND METHODS

Patients aged ≥18 years with human epidermal growth factor receptor-2-negative breast adenocarcinoma were randomised to Arm A: bevacizumab 10 mg/kg days 1 and 15; paclitaxel 90 mg/m(2) days 1, 8, and 15, every 4 weeks; or Arm B: bevacizumab 15 mg/kg day 1; capecitabine 1000 mg/m(2) b.i.d., days 1-14, every 3 weeks, until disease progression, unacceptable toxicity or consent withdrawal.

RESULTS

A post hoc interim safety analysis included 561 patients (Arm A: 284, Arm B: 277). The regimens demonstrated similar frequencies of all-grade and serious adverse events (SAEs), but different safety profiles. Treatment-related events occurred in 85.2% (Arm A) and 78.0% (Arm B) of patients. Fatigue was most common in Arm A (30.6% versus 23.5% Arm B), and hand-foot syndrome (HFS) most common in Arm B (49.5% versus 2.5% Arm A). Diarrhoea (Arm A: 0.4%, Arm B: 1.4%) and pulmonary embolism (Arm A: 0.7%, Arm B: 1.1%) were the most frequently reported SAEs.

CONCLUSION

These findings are in-line with safety data for bevacizumab plus paclitaxel or capecitabine, reported in previous phase III trials.

Brain metastases free survival differs between breast cancer subtypes

BACKGROUND

Brain metastases (BM) are frequently diagnosed in patients with HER-2-positive metastatic breast cancer; in addition, an increasing incidence was reported for triple-negative tumours. We aimed to compare brain metastases free survival (BMFS) of breast cancer subtypes in patients treated between 1996 until 2010.

METHODS

Brain metastases free survival was measured as the interval from diagnosis of extracranial breast cancer metastases until diagnosis of BM. HER-2 status was analysed by immunohistochemistry and reanalysed by fluorescent in situ hybridisation if a score of 2+ was gained. Oestrogen-receptor (ER) and progesterone-receptor (PgR) status was analysed by immunohistochemistry. Brain metastases free survival curves were estimated with the Kaplan-Meier method and compared with the log-rank test.

RESULTS

Data of 213 patients (46 luminal/124 HER-2/43 triple-negative subtype) with BM from breast cancer were available for the analysis. Brain metastases free survival differed significantly between breast cancer subtypes. Median BMFS in triple-negative tumours was 14 months (95% CI: 11.34-16.66) compared with 18 months (95% CI: 14.46-21.54) in HER-2-positive tumours (P=0.001) and 34 months (95% CI: 23.71-44.29) in luminal tumours (P=0.001), respectively. In HER-2-positive patients, co-positivity for ER and HER-2 prolonged BMFS (26 vs 15 m; P=0.033); in luminal tumours, co-expression of ER and PgR was not significantly associated with BMFS. Brain metastases free survival in patients with lung metastases was significantly shorter (17 vs 21 months; P=0.014).

CONCLUSION

Brain metastases free survival in triple-negative breast cancer, as well as in HER-2-positive/ER-negative, is significantly shorter compared with HER-2/ER co-positive or luminal tumours, mirroring the aggressiveness of these breast cancer subtypes.

P4-17-05: Brain Metastasis Free Survival (BMFS) Differs between Breast Cancer Subtypes

BACKGROUND Brain metastases (BM) are frequently diagnosed in patients (pts) with Her2-positive metastatic breast cancer (BC); a rising incidence was also reported in triple-negative disease. We hypothesized that pts with triple-negative or Her2-positive tumours had shorter BMFS as compared to other BC subtypes.

Therefore, we aimed to compare BMFS in pts with Her2-positive, estrogen receptor (ER) positive and triple-negative BC treated at the Medical University of Vienna from 1999–2009. In Her2-positive tumours, we further investigated the influence of ER co-expression on BMFS, as Her2-positive / ER-positive tumours were reported to express less aggressive biological properties.

METHODS BMFS was defined as primary study endpoint and measured as the interval from diagnosis of metastatic BC until diagnosis of BM. A total of 168 pts were identified from a breast cancer database. 34 pts were excluded from this analysis as brain was the first site of disease progression; hence complete datasets from 134 pts were available (69 Her2-positive; 33 triple-negative; 32 ER-positive).

Her2 status was analyzed by immunohistochemistry (IHC) and reanalyzed by FISH if a score of 2+ was gained. ER was analyzed by IHC; ER negative tumours were defined by a cut-off value of &lt;10% positively stained tumour cells. BMFS was estimated with the Kaplan-Meier product limit method and compared with the log-rank test; factors significantly associated with BMFS in the univariate analysis were included into a Cox proportional hazard model.

RESULTS Median BMFS in triple-negative pts was 14 months (m) (95% CI 12.17−15.83), as compared to 25 m (95% CI 13.37−36.62) in Her2-positive (p=0.001) and 35 m (95% CI 19.79−50.22) in ER-positive pts (p&lt;0.001), respectively.

In Her2-positive pts, prior trastuzumab treatment for metastatic disease prolonged median BMFS (29 vs. 11 m; p&lt;0.001); BMFS was further improved by trastuzumab in multiple lines (p=0.045) and co-positivity for ER and Her2 (30 vs. 15 m; p&lt;0.001).

ER-expression (HR 2.03; 95%CI 1.22−3.36; p&lt;0.05) and prior trastuzumab (HR 2.72; 95%CI 1.20−6.17; p=0.017) remained independent predictors of longer BMFS in the Cox regression model. In ER-positive, triple-negative as well as Her2-positive pts, no correlation was found between BMFS and factors such as grading, histological subtype, stage IV disease at primary diagnosis, disease-free interval &lt;24 months from primary treatment to diagnosis of metastatic disease, presence of visceral metastases, presence of lung metastases, and prior capecitabine exposure.

CONCLUSIONS BMFS in triple-negative disease is significantly shorter as compared to Her2-positive or ER-positive tumours, mirroring the aggressiveness of this breast cancer subtype. Probably due to improved systemic disease control, trastuzumab significantly prolonged BMFS in Her2-positive pts. Longer BMFS in ER/Her2 co-positive disease reflects a less aggressive subtype of Her2-positive breast cancer which is less likely to benefit from strategies of BM screening or prevention.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-17-05.

OT2-01-02: First-Line Bevacizumab in Combination with Capecitabine or Paclitaxel for HER2−Negative Locally Recurrent or Metastatic Breast Cancer (LR/MBC): A Randomized Phase III Trial

Background

A number of phase III studies have shown significant progression-free survival (PFS) benefits with the combination of bevacizumab (Bev) and either first-line capecitabine (X) or taxane therapy in LR/MBC. The ongoing open-label, randomized, phase III CECOG-sponsored TURANDOT study (CECOG/BC.1.3.005) is investigating the efficacy and safety of first-line Bev plus paclitaxel (P) versus Bev plus X in this setting.

Materials and methods: Eligible patients (pts) are aged ≥18 years with HER2−negative, chemonaïve LR/MBC, an ECOG performance status of 0–2 and a life expectancy &gt;12 weeks. Prior chemotherapy and concomitant hormonal therapy for LR/MBC are not permitted, but prior (neo)adjuvant chemotherapy is allowed if completed ≥6 months before randomization or ≥12 months if taxane based. Pts are randomized to receive Bev 10mg/kg days 1, 15 plus P 90mg/m2 days 1, 8, 15, q28d (Arm A) or Bev 15mg/kg day 1 plus X 1,000mg/m2 bid days 1–14, q21d (Arm B) until disease progression, unacceptable toxicity or withdrawal of consent. The primary objective is to demonstrate non-inferiority in overall survival (OS) with Bev plus P versus Bev plus X (upper limit ≤1.33 for the two-sided confidence interval for hazard ratio [HR]). Secondary objectives are: comparison of overall response rate (RECIST criteria); PFS; time to response; duration of response; time to treatment failure; safety (CTCAE version 3); and quality of life (EORTC QLQ-30). The recruitment target is 560 pts. A sample size of 490 pts in the per-protocol population will be required to provide 80% power to reject the null hypothesis of inferiority at a one-sided significance level of 0.025, assuming a 24-month median OS with Bev plus P and an alternative hypothesis of HR=1. Data cut-off for adverse event reports was 12 Apr 2010. Interim and final efficacy analyses will be triggered after 175 and 389 events, respectively.

Results: Recruitment to the study began in Sep 2008 and was completed in Aug 2010, with 561 pts randomized. Follow-up is ongoing.

Conclusions: TURANDOT is the first study to examine the efficacy and safety of Bev plus P versus Bev plus X as first-line treatment for pts with LR/MBC.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT2-01-02.

Abstract P5-11-02: The Carry-Over Effect of Adjuvant Zoledronic Acid: Comparison of 48- and 62-Month Analyses of ABCSG-12 Suggests That the Benefits of Combining Zoledronic Acid with Adjuvant Endocrine Therapy Persist Long after Completion of Therapy

Background: ABCSG-12 examined the efficacy of ovarian suppression using goserelin combined with tamoxifen (TAM) or anastrozole (ANA) ± zoledronic acid (ZOL) in premenopausal patients with endocrine-responsive early breast cancer. Results at 48 months and at 62 months show that adding ZOL significantly improved disease-free survival (DFS) and reduced disease recurrence.

Methods: Premenopausal patients with endocrine-responsive early breast cancer (N = 1,803) were randomized to goserelin (3.6 mg q28d) and TAM (20 mg/d) or ANA (1 mg/d) ± ZOL (4 mg q6mo) for 3 years. Endpoints included DFS and overall survival, both analyzed using log-rank test and Cox models.

Results: At 48 months’ median follow-up, ZOL significantly reduced the risk of DFS events by 36% versus no-ZOL (hazard ratio [HR] = 0.64; P = .01); this was maintained at 62 months’ follow-up (HR = 0.68; P = .009). In addition, the trend toward reduced risk of death with ZOL was maintained at both 48 months (HR = 0.60; P = .11) and 62 months (HR = 0.66; P = .10) compared with no-ZOL. Patients receiving ZOL also had fewer distant recurrences compared with no-ZOL: 29 versus 41 events at 48 months, and 44 versus 56 events at 62 months. No significant renal adverse events or confirmed cases of osteonecrosis of the jaw (ONJ) have been reported.

Conclusions: Comparisons of 48- and 62-month data suggest a possible carry-over of the ZOL anticancer benefit 2 years after treatment completion. Additional analyses will be presented, including disease outcomes during therapy and after treatment, as well as overall survival analyses.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-11-02.

Abstract PD01-03: Review of Capecitabine for the Treatment of Triple-Negative Early Breast Cancer

Background: Patients with triple-negative breast cancer (TNBC) have a high unmet therapeutic need with a generally poor prognosis. Initial data from two randomised, phase III trials of capecitabine (C) in early breast cancer (EBC), ABCSG-24 and FinXX, are promising. ABCSG-24 demonstrated significant improvements in pathological complete response (pCR) rate with the incorporation of C into a neoadjuvant regimen of epirubicin (E) plus docetaxel (D) (24.3% vs 16.0%; p=0.02) [Steger G, et al. ECCO-ESMO 2009; Abst 4BA]. FinXX revealed significant improvements in 3-year recurrence-free survival (RFS) with the addition of C to a sequential taxane-anthracycline adjuvant regimen (92.5% vs 88.9% control; hazard ratio [HR] 0.66, 95% CI 0.47-0.94; p=0.020) [Joensuu H, et al. Lancet Oncol 2009]. We review subgroup analyses from these two studies in patients with TNBC to assess the potential benefit of C in this patient subgroup.

Methods: Patients with operable breast cancer except T4d, ± nodal involvement were randomised in the ABCSG-24 study to 6x ED every 21 days (dl: E 75mg/m2 and D 75mg/m2, d2: pegfilgrastim 6mg) ± C (1,000mg/m2 b.i.d., d1-14). Patients with medium-to high risk EBC were randomised in the FinXX study to 3x D≥3x CycEF (D 80mg/m2 d1→cyclophosphamide [Cyc] 600mg/m2 d1, E 75mg/m2 d1, F 600mg/m2 d1, every 21 days) or 3x CD≥3x CycEC (C 900mg/m2 bid d1-15 + D 60mg/m2 d1→Cyc 600mg/m2 d1, E 75mg/m2 d1, C 900mg/m2 b.i.d., d1-15, every 21 days).

Results: Patients with TNBC in the ABCSG-24 study (n=122) had a significantly greater chance of achieving a pCR than non-TNBC (n=348) (odds ratio [OR] 5.29, 95% CI: 3.22-8.68, P&lt;0.0001), irrespective of the regimen. In the total study population, the highest pCR rates were achieved in patients with TNBC receiving EDC therapy (47.5% vs 31.2% with ED; p=NS). Patients with TNBC in the FinXX study (n=202) had significantly shorter RFS than patients without TNBC (n=1,294) (81.7% vs 92.2%, HR 0.43, 95% CI 0.29-0.63; P&lt;0.001). Within the TNBC subgroup, 3-year RFS was significantly longer in the C-containing arm (n=93) than in the control arm (n=109) (87.7% vs 76.6%, respectively; HR 0.43, 95% CI 0.21-0.90; p=0.024). RFS did not differ significantly in the C arm among patients with TNBC or non-TNBC (HR 0.74, 95% CI: 0.38-1.41; p=0.357). Conclusions: Initial data for C in EBC are promising with the ABCSG-24 and FinXX randomised, phase III trials demonstrating significant improvements in pCR and RFS, respectively, with the addition of C to standard (neo)adjuvant regimens. Exploratory subgroup analyses from these studies show additional benefit of C therapy in patients with TNBC, who are typically recognised as a group with poorer prognosis. An ongoing randomised, phase III study conducted by the CIBOMA collaborative group is prospectively investigating C maintenance therapy after adjuvant anthracycline/taxane in patients with TNBC. This is the first study of C to specifically target patients with early TNBC and interim safety data are expected in 2010.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD01-03.

Preoperative chemotherapy with cisplatin and docetaxel followed by surgery and clip-oriented postoperative chemoradiation in patients with localized gastric or gastroesophageal junction adenocarcinoma: results from a phase II feasibility study

BACKGROUND

We conducted a phase II feasibility study using preoperative chemotherapy with cisplatin and docetaxel followed by surgical resection and postoperative chemoradiation in patients with gastric or gastroesophageal cancer.

METHODS

Preoperative chemotherapy (two or three cycles) consisted of 50 mg/m(2) docetaxel and 50 mg/m(2) cisplatin. Surgical resection was planned 4 weeks after the last chemotherapy cycle. Patients underwent postsurgical chemoradiation, receiving a total dose of 39.6 Gy and 5-fluorouracil (5-FU) continuous infusion (350 mg/m(2)/day). The primary end-points were feasibility, overall response rate and R0 resectability rate after preoperative chemotherapy. The secondary end-points were tolerability, treatment-associated complications, disease-free survival and overall survival.

RESULTS

Between 2002 and 2004, 15 patients were enrolled in this study. After neoadjuvant treatment, two patients (13%) experienced progressive disease, four patients (27%) showed partial remission and nine patients (60%) showed stable disease. In 11 patients (73%) R0 resectability could be achieved. Six of these patients (54%) were able to undergo postoperative chemoradiation. Notably, five (83%) of these patients were disease free and alive at median follow-up of 72 months. Chemotherapy-associated neutropaenia and neutropaenic fever, anastomotic dehiscence, pulmonary embolism and acute pancreatitis were observed.

CONCLUSIONS

The combination of preoperative chemotherapy and postoperative chemoradiation is feasible in a significant subset of gastric cancer patients.

Modulation of plasma complement by the initial dose of epirubicin/docetaxel therapy in breast cancer and its predictive value

BACKGROUND

Despite the widespread use of neoadjuvant chemotherapy in breast cancer patients, prediction of individual response to treatment remains an unsolved clinical problem. Particularly, administration of an inefficient chemotherapeutic regimen should be avoided. Therefore, a better understanding of the molecular mechanisms underlying response to neoadjuvant chemotherapy is of particular clinical interest. Aim of the present study was to test whether neoadjuvant chemotherapy with epirubicin/docetaxel induces early changes in the plasma proteome of breast cancer patients and whether such changes correlate with response to therapy.

METHODS

Plasma samples of 25 breast cancer patients obtained before and 24 h after initiation of epirubicin/docetaxel-based neoadjuvant chemotherapy were analysed using two-dimensional differential gel electrophoresis (2D-DIGE). Protein spots found to be differentially expressed were identified using mass spectrometry and then correlated with the pathological response after six cycles of therapy. Markers identified in a discovery set of patients (n=12) were confirmed in an independent validation set (n=13).

RESULTS

2D-DIGE revealed 33 protein spots to be differentially expressed in response to chemotherapy, including the complement factors C1, C3 and C4, inter-α-trypsin inhibitor, α-1-antichymotrypsin and α-2-Heremans-Schmid glycoprotein (AHSG). With respect to cytokines, only interleukin (IL)-6, IL-10 and soluble intracellular adgesion molecule 3 (sICAM3) were minimally modulated. Moreover, two protein spots within the complement component C3 significantly correlated with response to therapy.

CONCLUSION

We have identified acute phase proteins and the complement system as part of the early host response to epirubicin/docetaxel chemotherapy. As complement C3 cleavage correlates with the efficacy of docetaxel/epirubicin-based chemotherapy, it has the potential as an easily accessible predictive biomarker.

Long-term persistence of acquired resistance to 5-fluorouracil in the colon cancer cell line SW620

Treatment resistance to antineoplastic drugs represents a major clinical problem. Here, we investigated the long-term stability of acquired resistance to 5-fluorouracil (FU) in an in vitro colon cancer model, using four sub-clones characterised by increasing FU-resistance derived from the cell line SW620. The resistance phenotype was preserved after FU withdrawal for 15weeks (~100 cell divisions) independent of the established level of drug resistance and of epigenetic silencing. Remarkably, resistant clones tolerated serum deprivation, adopted a CD133(+) CD44(-) phenotype, and further exhibited loss of membrane-bound E-cadherin together with predominant nuclear β-catenin localisation. Thus, we provide evidence for a long-term memory of acquired drug resistance, driven by multiple cellular strategies (epithelial-mesenchymal transition and selective propagation of CD133(+) cells). These resistance phenomena, in turn, accentuate the malignant phenotype.