Prognostic value of histopathologic traits independent of stromal tumor-infiltrating lymphocyte levels in chemotherapy-naïve patients with triple-negative breast cancer

BACKGROUND

In the absence of prognostic biomarkers, most patients with early-stage triple-negative breast cancer (eTNBC) are treated with combination chemotherapy. The identification of biomarkers to select patients for whom treatment de-escalation or escalation could be considered remains an unmet need. We evaluated the prognostic value of histopathologic traits in a unique cohort of young, (neo)adjuvant chemotherapy-naïve patients with early-stage (stage I or II), node-negative TNBC and long-term follow-up, in relation to stromal tumor-infiltrating lymphocytes (sTILs) for which the prognostic value was recently reported.

MATERIALS AND METHODS

We studied all 485 patients with node-negative eTNBC from the population-based PARADIGM cohort which selected women aged <40 years diagnosed between 1989 and 2000. None of the patients had received (neo)adjuvant chemotherapy according to standard practice at the time. Associations between histopathologic traits and breast cancer-specific survival (BCSS) were analyzed with Cox proportional hazard models.

RESULTS

With a median follow-up of 20.0 years, an independent prognostic value for BCSS was observed for lymphovascular invasion (LVI) [adjusted (adj.) hazard ratio (HR) 2.35, 95% confidence interval (CI) 1.49-3.69], fibrotic focus (adj. HR 1.61, 95% CI 1.09-2.37) and sTILs (per 10% increment adj. HR 0.75, 95% CI 0.69-0.82). In the sTILs <30% subgroup, the presence of LVI resulted in a higher cumulative incidence of breast cancer death (at 20 years, 58%; 95% CI 41% to 72%) compared with when LVI was absent (at 20 years, 32%; 95% CI 26% to 39%). In the ≥75% sTILs subgroup, the presence of LVI might be associated with poor survival (HR 11.45, 95% CI 0.71-182.36, two deaths). We confirm the lack of prognostic value of androgen receptor expression and human epidermal growth factor receptor 2 -low status.

CONCLUSIONS

sTILs, LVI and fibrotic focus provide independent prognostic information in young women with node-negative eTNBC. Our results are of importance for the selection of patients for de-escalation and escalation trials.

Abstract P1-13-10: Adjuvant treatment of HER2+ breast cancer: Should trastuzumab be given sequentially or concurrently with chemotherapy?

Background

Human Epidermal growth factor Receptor 2 positive (HER2+) breast cancers have a high risk of recurrence in the absence of systemic treatment. The monoclonal antibody trastuzumab in combination with chemotherapy has significantly improved survival. Randomized trials have given trastuzumab both concurrently and sequentially with chemotherapy. To date, only one study reported a comparison between concurrent and sequential trastuzumab, with a numerically but not statistically significant benefit for concurrent use.

Our aim is to evaluate whether there is a difference in survival between patients who received trastuzumab sequentially to chemotherapy compared to concurrently with chemotherapy using data from the population-based, Netherlands Cancer Registry (NCR).

Methods

All women diagnosed in the Netherlands with a HER2+, TanyNanyM0 breast tumor between 2005 and 2007 who received both chemotherapy and trastuzumab were identified from the NCR.

Kaplan Meier survival estimates and Cox regression were used to compare recurrence free survival (RFS) and overall survival (OS) by trastuzumab sequence. Hazard ratios (HR) were adjusted for grade, pathological T-stage, pathological N-stage, estrogen receptor (ER), progesterone receptor, radiotherapy, hormonal therapy and ovarian ablation.

Results

A total of 1,849 patients were identified, with a mean follow-up of 7.8 years. Of these, 1,260 received concurrent trastuzumab and 589 sequential trastuzumab. Most tumors were grade 3, node positive and ER+. During follow-up 358 RFS events occurred, 231 in the concurrently treated patients compared to 127 in sequentially treated patients. Regarding OS, 290 deaths were observed, 188 deaths in concurrently treated patients compared to 102 deaths in sequentially treated patients, respectively.

OS and RFS were similar among sequentially versus concurrently treated patients (adjusted HR 1.11; 95% CI 0.87-1.42; P=0.420 and adjusted HR 1.15; 95% CI 0.92-1.44; P=0.209, respectively).

Conclusion

We observed no significant difference in OS and RFS between patients who received sequential trastuzumab compared to patients treated concurrently. Based on our results no recommendation can be made favoring either of the two treatment sequences for the adjuvant treatment of HER2+ breast cancer patients.

Citation Format: Dackus GMHE, Jóźwiak K, Van der Wall E, Van Diest PJ, Hauptmann M, Siesling S, Sonke GS, Linn SC. Adjuvant treatment of HER2+ breast cancer: Should trastuzumab be given sequentially or concurrently with chemotherapy? [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 P1-13-10.

Optimal adjuvant endocrine treatment of ER+/HER2+ breast cancer patients by age at diagnosis: A population-based cohort study

BACKGROUND

Prior randomised controlled trials on adjuvant hormonal therapy included HER2_any patients; however, a differential effect of aromatase inhibitors (AIs) versus tamoxifen (TAM) may have been missed in ER+/HER2+ patients that comprise 7-15% of all breast cancer patients. In addition, a woman's hormonal microenvironment may influence sensitivity to TAM and AIs in the adjuvant setting, which changes during menopausal transition, a process that takes years. We studied the efficacy of AIs versus TAM in ER+/HER2+ breast cancer patients grouped by age at diagnosis as a proxy for menopausal status using treatment and outcome data from the nationwide population-based Netherlands Cancer Registry (NCR).

PATIENTS AND METHODS

All women diagnosed between 2005 and 2007 with endocrine-treated, T_anyN_anyM₀, ER+/HER2+ breast cancer were identified through the NCR (n = 1155). Patients were divided by age at diagnosis: premenopausal (≤45 years; n = 326), perimenopausal (45<years≤55; n = 304) and postmenopausal (>55 years; n = 525). A time-dependent variable, indicating whether AI or TAM was received for >50% of endocrine treatment duration, was applied to subdivide groups by predominant treatment received. Recurrence-free survival (RFS) and overall survival (OS) were assessed using Kaplan-Meier survival estimation and Cox regression. Hazard ratios (HRs) were adjusted for chemotherapy, trastuzumab, age at diagnosis, N-status, grade, pT-stage and ovarian ablation.

RESULTS

During follow-up, 237 recurrences and 182 deaths occurred. Perimenopausal women derived significant RFS and OS benefit from AI compared with TAM, HR 0.47 (95% CI 0.25-0.91; P = 0.03) and HR 0.37 (95% CI 0.18-0.79; P = 0.01), respectively, whereas premenopausal women derived no benefit from AI compared with TAM. Treatment effects differed significantly between these age groups (interaction P = 0.03 and P = 0.02, respectively). Among postmenopausal women a small but non-significant AI benefit was observed.

CONCLUSION

AI treatment, preferably without any TAM treatment, was associated with the best RFS and OS outcome in ER+/HER2+ perimenopausal breast cancer patients.

Abstract P2-09-16: How population-based data complement trial data in the adjuvant endocrine treatment of ER+/HER2+ breast cancers

Background

This study is part of the Netherlands Breast Cancer Project, initiated to address research questions that are unlikely answered by future randomized controlled trials (RCT). Here we investigated whether aromatase inhibitors (AI) are superior over tamoxifen (TAM), in the treatment of Estrogen Receptor (ER) positive Human Epidermal growth factor Receptor 2 (HER2) positive breast cancer, using treatment and outcome data from the population based Netherlands Cancer Registry (NCR). RCTs showed superiority of AI over TAM in postmenopausal ER+/HER2+ patients while a (non-significant) suggestion for worse outcome was observed among premenopausal patients treated with AI in the SOFT/TEXT trial. Perimenopausal women were not considered in these trials.

Methods

Dutch women without a prior malignancy, diagnosed between 2005-2007 with an ER+/HER2+, endocrine treated, non-metastatic, invasive breast cancer, were identified through the NCR and followed until 2013. Since data on menopausal status were lacking, we used age at diagnosis as a proxy to categorize patients as premenopausal (≤45 years), perimenopausal (45-55 years) and postmenopausal (&gt;55 years). A time-dependent variable was calculated indicating whether AI treatment was given for &gt;50% (denoted AI treated) vs. &lt;50% (denoted TAM treated) of endocrine treatment duration. Recurrence-free survival (RFS) and overall survival (OS) were assessed using an extended Kaplan-Meier survival estimator and Cox proportional hazards regression. Hazard Ratios (HR) for the TAM/AI comparison, were adjusted for chemotherapy, trastuzumab, age at diagnosis, lymph node status, grade, clinical T stage, and ovarian ablation.

Results

We included 1158 patients: 326 pre-, 306 peri- and 526 postmenopausal. Of these, 229 received TAM and 929 AI. During follow-up, 239 RFS and 184 OS events were observed. In the TAM treated group, 56 RFS and 45 OS events were observed, in the AI treated group 183 RFS and 139 RFS events were observed respectively.

No differences in RFS were observed comparing AI to TAM treated patients in the premenopausal (HR 1.33; 95% CI 0.71-2.49; P=0.378) and postmenopausal (HR 0.84, 95%CI 0.54-1.32; P=0.456) group. However, perimenopausal patients benefitted significantly from AI compared with TAM (HR 0.50; 95% CI 0.27-0.95). Results were similar for OS: no significant benefit from AI when compared to TAM in pre- (HR 1.41; 95% CI 0.62-3.19; P=0.408) and postmenopausal (HR 0.75; 95% CI 0.47-1.22; P=0.245) patients while perimenopausal patients derived significant benefit from AI treatment (HR 0.42; 95% CI 0.20-0.85; P=0.016).

Conclusion

In this population based cohort study we observed superiority for AI over TAM in the treatment of ER+/HER2+ perimenopausal patients. Data were suggestive in favor of AI when compared to TAM for postmenopausal patients while an indication of worse outcome with AI was seen in premenopausal patients, consistent with results of the SOFT/TEXT trial. Although we used age as a proxy for menopausal status, our results are consistent with previous RCTs. Population based data may therefore provide a reliable source of information when new RCTs might not be feasible anymore.

Citation Format: Dackus GMHE, Jozwiak K, Sonke GS, Van der Wall E, Van Diest PJ, Hauptmann M, Siesling S, Linn SC. How population-based data complement trial data in the adjuvant endocrine treatment of ER+/HER2+ breast cancers [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 P2-09-16.

Abstract P5-08-07: The long-term prognosis of breast cancers patients diagnosed ≤40 years in the absence of adjuvant systemic therapy

This abstract was withdrawn by the authors.

Abstract PD5-02: The effect of trastuzumab-based therapy on overall survival in small, node-negative HER2-positive breast cancer: To treat or not to treat?

Background Since the addition of trastuzumab to (neo)adjuvant chemotherapy, the prognosis of patients with stage II and III HER2-positive breast cancer has significantly improved. Several reports have subsequently shown that small, node-negative tumors also carry a relatively poor prognosis and patients with HER2-positive tumors of 2cm or less increasingly receive trastuzumab-based chemotherapy. We sought to provide evidence for the effect of this approach in a population-based cohort.

Methods All patients diagnosed with T1N0 HER2-positive breast cancer in the Netherlands between 2006 and 2012 were identified from the nationwide Netherlands Cancer Registry. Patient, tumor, and treatment characteristics were recorded. The primary outcome was overall survival and analyses were performed for the whole group and for T1a, T1b, and T1c tumors separately. Kaplan-Meier survival rates were compared between groups with and without systemic treatment and multivariate cox regression analysis was performed to adjust for baseline characteristics.

Results A total of 3512 eligible patients were identified of whom 385 had a T1a tumor (≤0.5cm, including 54 micro-invasive), 800 had a T1b tumor (&gt;0.5 to 1cm), and 2327 had a T1c tumor (&gt;1cm to 2cm). Systemic treatment with chemotherapy and/or trastuzumab was administered in 45% of patients: 7% in T1a, 19% in T1b, and 60% in T1c tumors. Of the treated patients, the majority (92%) received both chemotherapy and trastuzumab. The use of systemic treatment increased significantly over time and varied according to geographic region. Other factors associated with receiving systemic treatment in multivariate analysis were younger age, negative hormone receptor status, higher tumor grade, larger tumor size and presence of isolated tumor cells in the lymph nodes.

At a median follow-up of 49 months (interquartile range [IQR] 30-69), 186 deaths had occurred. Treatment with chemotherapy and/or trastuzumab significantly improved overall survival at seven years follow-up (95% versus 87%; hazard ratio [HR] 0.30; 95% confidence interval [CI] 0.20-0.44, p&lt;0.001). This effect was seen in all three tumor size groups: 100% versus 91% in T1a, 99% versus 91% in T1b, and 95% versus 83% in T1c tumors. When corrected for age the beneficial effect of systemic treatment on overall survival remained highly significant (HR 0.46; 95% CI 0.30-0.70, p&lt;0.001). Due to the small number of events in the treated group, correction for additional variables in multivariate analysis was not feasible. However, the otherwise unfavorable prognostic profile in the treated patients (hormone receptor status, grade, size, isolated tumor cells), suggests an even stronger actual effect of systemic treatment. To ensure that the excess mortality in the non-treated group was due to breast cancer and not the result of other causes, breast-cancer specific survival analyses will follow.

Conclusion Systemic treatment with chemotherapy and/or trastuzumab improves overall survival in T1a, T1b, and T1c node-negative HER2-positive breast cancer.

Citation Format: van Ramshorst MS, van der Heijden-van der Loo M, Dackus GMHE, Linn SC, Sonke GS. The effect of trastuzumab-based therapy on overall survival in small, node-negative HER2-positive breast cancer: To treat or not to treat?. [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 PD5-02.

Abstract OT1-03-10: A phase I followed by a randomized phase II trial of two cycles carboplatin-olaparib followed by olaparib monotherapy versus capecitabine in BRCA-1 or -2 mutated Her2 negative advanced breast cancer as first line treatment (REVIVAL study)

Background

Preclinical studies revealed that the combination of platinum compounds and olaparib is additive and possibly even synergistic in cell models with BRCA1 or -2 mutations. Early clinical trials suggested high benefit of olaparib with induction carboplatin in BRCA1 and -2 mutation carrier enriched populations. However, there is no evidence yet that carboplatin-olaparib has a superior benefit-risk compared to current standard therapy in advanced breast cancer in BRCA1 and -2 mutation carriers.

Trial design

We initiated a phase-I/II study due to an olaparib formulation change from capsule to tablet. During phase-I a traditional 3+3 dose escalation study is performed. Carboplatin will be dose escalated in 1 step from AUC 3 to AUC 4 with a constant olaparib dose of 25 mg BID. Olaparib is then dose escalated in 3 steps to 50, 75 and 100 mg BID until &gt; 1/6 patients develop a DLT, the previous safe dose-level will be determined the MTD. After the MTD is established a randomised phase-II trial will be initiated where patients are randomised between standard capecitabine 1250 mg/m2 BID day 1-14, q day 22 or 2 cycles carboplatin-olaparib followed by olaparib monotherapy 300mg BID. After progression, patients in the experimental arm receive capecitabine, all other patients receive physicians choice of paclitaxel, vinorelbine or eribulin at standard dose. A compassionate use program with olaparib is available for patients in the standard arm after progression on second line treatment.

Eligibility criteria

In phase-II patients with histological or cytological proof of advanced BRCA1 or -2 mutated HER2 negative breast cancer are eligible if they are ≥18 years, have measureable disease according to RECIST 1.1 criteria, a WHO performance status of 0–2, a life expectancy ≥ 3 months and a negative pregnancy test. Pretreatment should contain an anthracycline and/or taxane in the (neo)adjuvant setting, unless not indicated. In the advanced setting only hormonal pre-treatment is allowed. Minimal laboratory values ANC ≥ 1.5 x 109 /L, Hb ≥ 6.2 mM (no transfusions in the last 28 days), platelet count ≥ 100 x 109 /L, serum bilirubin &lt; 1.5 x ULN, ASAT and ALAT &lt; 2.5 x ULN and a serum creatinine &lt; 1.5 x ULN or creatinine clearance ≥ 50 mL/min.

Aims

In phase-1 we establish the MTD for treatment in phase-II where we study progression free survival on first line treatment(PFS1) compared with standard of care capecitabine.

Statistical methods

Toxicity analysis in phase-I can take place after all patients completed their 28 day DLT period.

A total of 104 events in 110 patients on first line treatment need to be observed in phase-II to detect a clinical meaningful improvement in median PFS1 in the experimental arm from 4 to 7 months, assuming an accrual of 2 years and a follow-up of ≥6 months, providing a power of 80% (two-sided significance level of 5%). An interim analysis for futility and efficacy will be performed when 52 events have been observed.

Accrual

It is expected that 15-20 patients are needed in phase-I, inclusion is due around November 2015. Phase-II will be multicentre and is expected to start accrual December 2015.

Citation Format: Dackus GMHE, Schouten PC, Geenen JJ, Marchetti S, Sonke GS, Linn SC, Schellens JHM. A phase I followed by a randomized phase II trial of two cycles carboplatin-olaparib followed by olaparib monotherapy versus capecitabine in BRCA-1 or -2 mutated Her2 negative advanced breast cancer as first line treatment (REVIVAL study). [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 OT1-03-10.

Abstract S6-06: The effect of trastuzumab-based therapy on overall survival in small, node-negative HER2-positive breast cancer: To treat or not to treat?

Background Since the addition of trastuzumab to (neo)adjuvant chemotherapy, the prognosis of patients with stage II and III HER2-positive breast cancer has significantly improved. Several reports have subsequently shown that small, node-negative tumors also carry a relatively poor prognosis and patients with HER2-positive tumors of 2cm or less increasingly receive trastuzumab-based chemotherapy. We sought to provide evidence for the effect of this approach in a population-based cohort.

Methods All patients diagnosed with T1N0 HER2-positive breast cancer in the Netherlands between 2006 and 2012 were identified from the nationwide Netherlands Cancer Registry. Patient, tumor, and treatment characteristics were recorded. The primary outcome was overall survival and analyses were performed for the whole group and for T1a, T1b, and T1c tumors separately. Kaplan-Meier survival rates were compared between groups with and without systemic treatment and multivariate cox regression analysis was performed to adjust for baseline characteristics.

Results A total of 3512 eligible patients were identified of whom 385 had a T1a tumor (≤0.5cm, including 54 micro-invasive), 800 had a T1b tumor (&gt;0.5 to 1cm), and 2327 had a T1c tumor (&gt;1cm to 2cm). Systemic treatment with chemotherapy and/or trastuzumab was administered in 45% of patients: 7% in T1a, 19% in T1b, and 60% in T1c tumors. Of the treated patients, the majority (92%) received both chemotherapy and trastuzumab. The use of systemic treatment increased significantly over time and varied according to geographic region. Other factors associated with receiving systemic treatment in multivariate analysis were younger age, negative hormone receptor status, higher tumor grade, larger tumor size and presence of isolated tumor cells in the lymph nodes.

At a median follow-up of 49 months (interquartile range [IQR] 30-69), 186 deaths had occurred. Treatment with chemotherapy and/or trastuzumab significantly improved overall survival at seven years follow-up (95% versus 87%; hazard ratio [HR] 0.30; 95% confidence interval [CI] 0.20-0.44, p&lt;0.001). This effect was seen in all three tumor size groups: 100% versus 91% in T1a, 99% versus 91% in T1b, and 95% versus 83% in T1c tumors. When corrected for age the beneficial effect of systemic treatment on overall survival remained highly significant (HR 0.46; 95% CI 0.30-0.70, p&lt;0.001). Due to the small number of events in the treated group, correction for additional variables in multivariate analysis was not feasible. However, the otherwise unfavorable prognostic profile in the treated patients (hormone receptor status, grade, size, isolated tumor cells), suggests an even stronger actual effect of systemic treatment. To ensure that the excess mortality in the non-treated group was due to breast cancer and not the result of other causes, breast-cancer specific survival analyses will follow.

Conclusion Systemic treatment with chemotherapy and/or trastuzumab improves overall survival in T1a, T1b, and T1c node-negative HER2-positive breast cancer.

Citation Format: van Ramshorst MS, van der Heijden-van der Loo M, Dackus GMHE, Linn SC, Sonke GS. The effect of trastuzumab-based therapy on overall survival in small, node-negative HER2-positive breast cancer: To treat or not to treat?. [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 S6-06.