Influence of side-effects on early therapy persistence with letrozole in post-menopausal patients with early breast cancer: Results of the prospective EvAluate-TM study

BACKGROUND

Endocrine treatment (ET) with an aromatase inhibitor (AI) is the treatment of choice in post-menopausal patients with hormone receptor-positive early breast cancer (EBC). However, adverse events (AEs) often lead to treatment discontinuation. This analysis aimed to identify side-effects that lead to patients failing to persist with letrozole treatment.

PATIENTS AND METHODS

Post-menopausal hormone receptor-positive EBC patients starting ET with letrozole were enroled in EvAluate-TM, a non-interventional study. Information regarding treatment compliance and persistence was gathered in months 6 and 12. Persistence was defined as the time from 30 d after the start to the end of treatment. The influence on persistence of musculoskeletal syndrome, menopausal disorder, sleep disorder and other AEs within the first 30 d was analysed using Cox regression analyses.

RESULTS

Among 3887 patients analysed, the persistence rate after 12 months was >85%. In all, 568 patients (14.6%) discontinued the treatment, 358 of whom (63.0%) did so only because of side-effects. The main AEs influencing persistence were musculoskeletal symptoms (hazard ratio [HR] 2.55; 95% confidence interval [CI], 1.90-3.42), sleep disorders (HR 1.95; 95% CI, 1.41-2.70) and other AEs (HR 2.03; 95% CI, 1.51-2.73). Menopausal disorder was not associated with non-persistence (HR 1.17; 95% CI, 0.74-1.84).

CONCLUSIONS

These results suggest that side-effects of AIs such as musculoskeletal syndrome and sleep disorder lead to ET discontinuation within the first treatment year in significant numbers of EBC patients. Compliance programmes adapted for subgroups that are at risk for early non-persistence might help to ensure the recommended therapy duration.

CLINICAL TRIALS NUMBER

CFEM345DDE19.

Abstract P6-15-03: Outcome after neoadjuvant chemotherapy in elderly breast cancer patients – a pooled analysis of individual patient data from eight prospectively randomized controlled trials

Introduction: Recent studies showed the high and independent impact of age (<40 years) on pathologic complete remission (pCR) and prognosis for patients undergoing neoadjuvant chemotherapy (NACT). Some physicians might not consider elderly patients (>65 years) for NACT due to poor prognosis or higher toxicity. The aim of this analysis is to help selecting appropriately elderly women who would benefit from NACT. Secondly, survival parameters will be investigated in several clinical and histological subgroups.

Methods: From 1998 to 2010, eight prospectively randomized German Breast Group (GBG) trials of anthracycline- and taxane-based NACT were performed and analyzed in this study.

Results: Compared to the overall average, women older than 65 years had significant larger tumors and more overall lymph node involvement. Also, compared to patients younger than 51 years, they had more lobular invasive tumors. Histologically, they had more G2 tumors, more estrogen-receptor positive tumors. PCR (ypT0 ypN0) was strongly associated with age: >65y: 11.7%; 51-65y: 14.1%; 40-50y: 17.3%; <40y: 20.9%. The multivariable logistic regression analysis of clinical parameters showed that young age, clinical stage T4, invasive ductal cancer and poor differentiated breast cancer are predictive for high pCR. The multivariate analyses of molecular subgroups also showed that age >65years is a predictor of significant (p<0.05) lower pCR in TNBC and HR positive/HER2- breast cancers. Nonetheless, in this cohort, HER2+ patients showed pCR rates as high - and for HR+/HER2+ even higher - pCR rates compared to younger patients.

Discussion: This study underlines the unfavorable impact of higher age on pCR, but it shows nevertheless a realistic chance for pCR if NACT is applied - especially for HER2+ patients. Furthermore, elderly patients in this analysis with non-TNBC have a good prognosis (comparable to younger patients) regarding OS, even if they do not have pCR.

Citation Format: von Waldenfels G, Loibl S, Furlanetto J, Anna M, Lederer B, Denkert C, Hanusch C, Huober J, Jackisch C, Kümmel S, von Minckwitz G, Schneeweiss A, Untch M, Rhiem K, Fasching PA, Blohmer JU. Outcome after neoadjuvant chemotherapy in elderly breast cancer patients – a pooled analysis of individual patient data from eight prospectively randomized controlled 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 P6-15-03.

Abstract P6-15-01: Withdrawn

This abstract was withdrawn by the authors.

Abstract P6-13-01: Withdrawn

This abstract was withdrawn by the authors.

Abstract PD7-09: Changes in hormone levels (E2, FSH, AMH) and fertility of young women treated with neoadjuvant chemotherapy (CT) for early breast cancer (EBC)

Background:

We previously demonstrated that the majority of women ≤45 years experienced chemotherapy-induced ovarian failure (CIOF) after CT for EBC. Age, CT regimen, duration and dose-density influenced the rate of CIOF. The regain of premenopausal Follicle-Stimulating Hormone (FSH) and Estradiol (E2) levels after chemotherapy is not equivalent to fertility restoration. The Anti-Muellerian Hormone (AMH) assessment seems to be more accurate than other hormones in predicting the ovarian reserve. FSH, E2 and AMH have been prospectively assessed in young patients receiving (neo)adjuvant CT.

Methods:

740 patients (pts) aged ≤45yrs treated with anthracycline or taxane-based CT for EBC from 4 German neoadjuvant/adjuvant trials were included. Blood samples were collected at baseline before CT (N=740), end of treatment (EOT n=740), 6 (n=177), 12 (n=113), 18 (n=69), 24 (n=47) months (m) after EOT. Only the full set of samples of a given patient was included. FSH, E2 and AMH were centrally assessed. Postmenopausal hormone levels of FSH and E2 according to the central laboratory were defined as FSH>12.4IU/l and E2<52.2ng/l; fertile level of AMH as ≥0.22ng/ml. Regain of premenopausal hormone levels was defined as the time point from EOT to premenopausal FSH and E2 level regain and was assessed only for those pts with postmenopausal FSH and E2 levels at EOT. Pts with no regain have been censored at the date of the last hormone assessment.

Results:

Median age was 40yrs (range 21-45); 57.2% had BMI 18.5-<25, 41.1% ≥25; 32% had luminal-like, 35.9% HER2+, 32.0% triple-negative BC. Median hormone levels at different time points are presented in Table 1. Before chemotherapy 14.2% of pts had non-fertile hormone levels of AMH despite premenopausal levels of FSH and E2 compared to 77.3% of pts with postmenopausal levels (p<0.001); at EOT 77.4% vs 99.8% (p<0.001); at 6m 82.1% vs 100% (p<0.001); at 12m 80.7% vs 98.4% (p=0.002); at 18m 66.7% vs 100% (p<0.001); at 24 m 72.4% vs 100% (p=0.017). Similar results were observed in 47 pts with all time point samples available. Of 147 pts with postmenopausal hormone levels of FSH and E2 at EOT, 32.7% (95%CI 25.7%-40.9%) regained premenopausal hormone levels within 6m, 51.0% (95%CI 42.3%-60.4%) within 12m, 66.6% (95%CI 55.2%-77.6%) within 18m and 69.9% (95%CI 57.8%-81.3%) within 24m.

Conclusion:

Nearly 70% of women regain premenopausal hormone levels of FSH and E2 within 2 years after end of CT. Despite that, only less than one third maintain their fertility potential as predicted by AMH. AMH is a very sensitive marker for the prediction of fertility function after CT for EBC.

Table 1 Median and range of FSH, E2 and AMH levels per time pointsTimepointFSH,IU/lE2, ng/mLAMH, ng/ml% of pts with AMH levels above dtBaseline6.0 [dt-142.7]88.0 [dt-2375.0]0.96 [dt-16.18]95.4EOT76.1 [1.9-225.0]dt [dt-632.0]dt [dt -3.11]15.66 m41.4 [1.1-190.6]10.0 [dt-929.0]dt [dt -3.11]26.112 m28.7 [1.1-146.0]11.0 [dt-947.0]dt [dt -2.81]29.218 m20.6 [0.8-172.3]19.0 [dt-624.0]dt [dt -1.89]34.824 m16.30 [dt-93.9]44.0 [dt-11795.0]dt [dt -1.75]38.3Abbreviations: dt, detectable threshold, EOT, end of treatment; m, month; pts, patients. Detectable threshold: FSH<0.1IU/l, E2<5ng/l, AMH<0.03ng/ml

Citation Format: Furlanetto J, Thode C, Huober J, Denkert C, Bassy M, Hanusch C, Jackisch C, Kümmel S, Schneeweiss A, Untch M, Fasching PA, Karn T, Marmé F, van Mackelenbergh M, Müller V, Schem C, von Minckwitz G, Strik D, Nekljudova V, Loibl S. Changes in hormone levels (E2, FSH, AMH) and fertility of young women treated with neoadjuvant chemotherapy (CT) for early breast cancer (EBC) [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 PD7-09.

Significant Changes in Circulating Plasma Levels of IGF1 and IGFBP3 after Conventional or Dose-Intensified Adjuvant Treatment of Breast Cancer Patients with one to three Positive Lymph Nodes

The insulin-like growth factor 1 (IGF1) and its binding protein IGFBP3 (insulin-like growth factor binding protein 3) play a pivotal role during the growth and development of tissues. The purpose of this study was to evaluate the influence of anthracycline- and taxane-containing adjuvant chemotherapy in breast cancer patients on the circulating plasma levels of IGF1 and its main binding protein, IGFBP3. This investigation was part of a prospective randomized phase III study in which breast cancer patients were treated with either conventional or dose-intensified adjuvant chemotherapy. The factors were quantified in the plasma of 151 patients with a commercially available sandwich enzyme immunoassay. Before therapy, both parameters were within the normal range in most patients (n=145 and n=144). After therapy, both factors had increased significantly by 29% (IGF1) and 19% (IGFBP3), with the highest increase being observed in the dose-intensified group. Correlations with patient and tumor characteristics revealed a relatively higher increase in both parameters in premenopausal patients, patients with lower-grade tumors, more positive lymph nodes, larger tumor volume, and positive hormone receptor status. No correlation was found with the HER2 expression of the tumors.

Dual HER2-blockade with pertuzumab and trastuzumab in HER2-positive early breast cancer: a subanalysis of data from the randomized phase III GeparSepto trial

Background

The neoadjuvant phase III GeparSepto study showed that substituting nab-paclitaxel for standard solvent-based paclitaxel significantly improved the pathologic complete response (pCR) rate achieved with a sequential neoadjuvant chemotherapy regimen of paclitaxel, epirubicin, and cyclophosphamide for high-risk primary breast cancer. Recent trials demonstrated that in HER2+ breast cancer pCR can be increased by using pertuzumab in addition to trastuzumab and chemotherapy. The present analysis focuses on efficacy and safety data from the subset of patients with HER2+ tumors from the GeparSepto trial (n = 396) in comparison to the HER2- cohort.

Patients and methods

Patients with histologically confirmed breast cancer (n = 1206) received four cycles of weekly paclitaxel [either solvent-based (Pac) or nab-paclitaxel (nab-Pac), according to randomization] followed by 4 cycles of epirubicin 90 mg/m2 plus cyclophosphamide 600 mg/m2 q3w, with concurrent trastuzumab and pertuzumab q3w for those with HER2+ tumors. The primary endpoint was pCR defined as ypT0 ypN0.

Results

Higher rates of pCR were achieved in HER2+ than in HER2- tumors (57.8% versus 22.0%, P < 0.0001), with the highest rate in the HER2+/HR- cohort (71.0%; 66.7% Pac, 74.6% nab-Pac). In HER2+/HR+ tumors, the pCR rate was 52.9% (49.7% Pac, 56.4% nab-Pac). Grade ≥3 toxic effects were significantly more common in HER2+ than in HER2- patients, with grade 3-4 diarrhea in 7.6% versus 0.9% (P < 0.001) and febrile neutropenia in 6.3% versus 3.3% (P = 0.023) of patients. Left ventricular ejection fraction decreases from baseline were uncommon, with 2.0% versus 0.4% of patients showing decreases to <50% along with a ≥10% decrease from baseline.

Conclusion

In HER2+ early breast cancer, a dual HER2-targeted combination of pertuzumab and trastuzumab, together with taxane-epirubicin-cyclophosphamide neoadjuvant chemotherapy, achieved high rates of pCR.

Expression of Cyclin D1 protein in residual tumor after neoadjuvant chemotherapy for breast cancer

PURPOSE

Hormone receptor (HR)-positive breast cancer (BC) shows a poor response to neoadjuvant chemotherapy (NACT). New treatment targets like the Cyclin D1-CDK4/CDK6 complex are promising adjuvant/post-neoadjuvant therapeutic strategies. Evaluating Cyclin D1 overexpression in residual tumor could recognize those patients that benefit most from such post-neoadjuvant treatment. In this study, we determined Cyclin D1 expression in residual BC after NACT. Secondary aims were to correlate Cyclin D1 expression levels with clinicopathological parameters and to assess its prognostic value after NACT.

METHODS

We retrospectively assessed the nuclear expression of Cyclin D1 on tissue microarrays with residual tumor from 284 patients treated in the neoadjuvant GeparTrio (n = 186) and GeparQuattro (n = 98) trials. Evaluation was performed with a standardized immunoreactive score (IRS) after selecting a cut-off value.

RESULTS

A high expression level (IRS ≥ 6) of Cyclin D1 was found in 37.3% of the assessed specimens. An increased Cyclin D1 expression was observed in HR-positive tumors, compared to HR-negative tumors (p = 0.02). Low Cyclin D1 levels correlated with clinical tumor stage 1-3 (p = 0.03). Among patients with HR-positive/Her2-negative tumors and high Cyclin D1 expression, a better disease-free survival (DFS) was graphically suggested, but not significant (p = 0.21).

CONCLUSION

Our study demonstrates a measurable nuclear expression of Cyclin D1 in post-neoadjuvant residual tumor tissue of HR-positive BC. Cyclin D1 expression was not prognostic for DFS after NACT. Our results and defined cut-off suggest that the marker can be used to stratify tumors according to protein expression levels. Based on this, a prospective evaluation is currently performed in the ongoing Penelope-B trial.

Budget impact analysis of gene expression tests to aid therapy decisions for breast cancer patients in Germany

OBJECTIVES

Many women with early-stage, hormone receptor-positive breast cancer may not benefit from adjuvant chemotherapy. Gene expression tests can reduce chemotherapy over- and undertreatment by providing prognostic information on the likelihood of recurrence and, with Oncotype DX, predictive information on chemotherapy benefit. These tests are currently not reimbursed by German healthcare payers. An analysis was conducted to evaluate the budget impact of gene expression tests in Germany.

MATERIALS AND METHODS

Costs of gene expression tests and medical and non-medical costs associated with treatment were assessed from healthcare payer and societal perspectives. Costs were estimated from data collected at a university hospital and were combined with decision impact data for Oncotype DX, MammaPrint, Prosigna and EndoPredict (EPclin). Changes in chemotherapy use and budget impact were evaluated over 1 year for 20,000 women.

RESULTS

Chemotherapy was associated with substantial annual costs of EUR 19,003 and EUR 84,412 per therapy from the healthcare payer and societal perspective, respectively. Compared with standard care, only Oncotype DX was associated with cost savings to healthcare payers and society (EUR 5.9 million and EUR 253 million, respectively). Scenario analysis showed that both women at high clinical but low genomic risk and low clinical but high genomic risk were important contributors to costs.

CONCLUSIONS

Oncotype DX was the only gene expression test that was estimated to reduce costs versus standard care in Germany. The reimbursement of Oncotype DX testing in standard clinical practice in Germany should be considered.

Abstract P1-09-05: The role of immune and apoptosis markers for prediction of pCR in the WSG-ADAPT HER2+/HR+ phase II trial evaluating 12-weeks of neoadjuvant TDM1 ± endocrine therapy (ET) versus T + ET in HER2-positive hormone-receptor-positive early breast cancer (EBC)

Background: Immune and apoptosis biomarkers are potential prognostic/predictive markers in HER2+ EBC. High PD-L1 expression was shown to be predictive for lower pCR after chemotherapy+trastuzumab+/-pertuzumab, particularly in HER2+, ER- disease. Yet, HER2+ EBC co-expressing hormone receptors is a distinct entity.

The ADAPT HER2+/HR+ phase II trial (n=376) compared 12 weeks of neoadjuvant T-DM1 + ET vs. trastuzumab (T)+ET and demonstrated pCR rates of about 41% in both (well tolerated) T-DM1 arms.

Methods: In order to identify potential early predictors for pCR (i.e. no invasive tumor in breast and lymph nodes), immune markers (PDL1 on infiltrating immune cells (IIC) and on tumor cells (TC); CD8 in invasive margin and in tumor center) and apoptosis markers (bcl-2; mcl-2) were determined by immunohistochemistry (IHC; H-scores) in core biopsy sections obtained at primary diagnosis and at cycle 2. For multivariate logistic regression, each biomarker (separately), clinical factors (Ki-67, cT, cN) and therapy were entered. All analyses were exploratory.

Results:Biomarkers were available in up to 326 patients (pts) at baseline and up to 170 pts at 3 weeks (due to low tumor content in 2nd core biopsy).

Baseline IIC-PDL1 was associated with pCR in the T-DM1 arm (OR 2.89; 95%CI: 1.11-7.51); IIC-PDL1 at cycle 2 was not associated with pCR.

PD-L1 expression in TC was rare (2%); cycle-2 TC-PD-L1 was associated with pCR in all pts and in the pooled TDM-1 arms.

High baseline CD8 in tumor center was associated with pCR in the whole cohort (OR 2.4; CI: 1.04 – 5.5) and in the T+ET arm (OR=10.1; CI: 1.12 - 91.6) and at cycle 2 in all pts (OR=9.52; CI: 2.17 – 41), in pooled TDM-1 arms (OR=15.7; CI: 2.49 – 99), and in TDM-1+ET (OR=25.05; CI: 2.12 – 295). Increases in this marker also predicted pCR in all pts, pooled TDM-1, and in TDM-1+ET. Association of cycle-2 CD8 in tumor center with pCR persisted in multivariate models.

Lower baseline CD8 in invasive margin was associated with pCR in the T-DM1 arm (OR=0.09; CI: 0.01-0.69), but at cycle 2 in all pts (OR=18.1; CI: 1.60 – 204) and in pooled TDM-1 arms (OR=23.5; CI: 1.1 - 500). This positive impact persisted in multivariate models.

Bcl-2 expression at baseline was associated with non-pCR in all pts (OR=0.28, CI: 0.12 - 0.66), in the pooled T-DM1 arms (OR=0.216, CI: 0.08 - 0.61), and particularly in the T-DM1+ET arm (OR=0.14; CI: 0.03 - 0.71). This association persisted in multivariate analysis. At cycle 2, lower bcl-2 had OR=0.16 (CI: 0.03 - 0.96) in the pooled T-DM1 arms. No association with efficacy was seen for mcl-1.

Conclusions: The WSG-ADAPT HER2+/HR+ phase II trial is the first international trial to focus on HER2+/HR+ EBC alone and the first to show substantial pCR rates of &gt; 40% after only 12 weeks of T-DM1 -- without standard chemotherapy.

Expression of bcl-2 may affect resistance to T-DM1. High immune activity at baseline and/or cycle 2 seems to be associated with pCR. The association of CD8 expression and its changes with therapy efficacy is complex and could depend on ET.

Further biomarker analyses are ongoing and will be presented at the meeting.

Citation Format: Harbeck N, Nitz UA, Matthias C, Kates R, Braun M, Kümmel S, Schumacher C, Potenberg J, Kraemer S, Kleine-Tebbe A, Augustin D, Aktas B, Forstbauer H, Tio J, Liedtke C, Grischke E-M, de Haas SL, Deurloo R, Schumacher J, Wuerstlein R, Kreipe HH, Gluz O. The role of immune and apoptosis markers for prediction of pCR in the WSG-ADAPT HER2+/HR+ phase II trial evaluating 12-weeks of neoadjuvant TDM1 ± endocrine therapy (ET) versus T + ET in HER2-positive hormone-receptor-positive early breast cancer (EBC) [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 P1-09-05.

Abstract P1-09-11: Outcome after neoadjuvant chemotherapy in progesterone receptor negative breast cancer patients – A pooled analysis of individual patient data from ten prospectively randomized controlled neoadjuvant trials

Background

The estrogen receptor (ER) as a nuclear transcription factor alters the transcription of estrogen sensitive genes to which the progesterone receptor gene belongs. The ER has also been described to exert non genomic effects by interacting with several cell signalling pathways that do not initially involve increases in gene transcription. These different patterns of action of the ER lead to the assumption that in tumors that utilize the non-genomic ER activity in order to stimulate tumorigenesis and proliferation progesterone receptor (PgR) expression would be decreased or absent. Therefore lack of PgR expression could be a surrogate marker of altered growth factor signalling. The aim of this study was to investigate if PgR expression may act as a predictive factor for response to neoadjuvant chemotherapy and long-term outcome in breast cancer patients.

Methods

5613 patients with primary breast cancer, follow-up, positive ER expression; HER2+ and HER2- from overall 10 (n=9785) German neoadjuvant trials receiving an anthracycline and taxane based chemotherapy were included. The pathologic complete response (pCR)(ypT0, ypN0), long term survival data (disease free survival (DFS), distant disease free survival (DDFS), overall survival (OS) and local recurrence free survival (LRFS)) and early relapse, defined as DFS &lt;37 months, were compared according to their PgR expression, overall and in subgroups defined by HER2.

Results

Tumors lacking PgR expression (1172 patients) were more often of grade 3 (38.4% v 26.3%; p&lt;0.001), tended to have an advanced clinical nodal involvement (6.8% v 4.7%; p=0.004) and were more likely to demonstrate HER2 positivity (36.2% v 22.3%; p&lt;0.001).

pCR rates were significantly higher in PgR negative patients in the entire cohort (13.8% v 7.5%; p&lt;0.001) as well as in the HER2 negative subgroup (11.2% v 5.8%; p&lt;0.001) whereas there was no significant difference in the HER2 positive (22.1% v 18%; p=0.117). After adjusting for known predictive factors in the multivariable logistic regression analysis PgR negativity was an independent predictive factor for pCR overall (OR 1.76; p&lt;0.001) and in the HER2 negative patients (OR 1.99; p&lt;0.001).

PgR negativity was also significantly associated with an early relapse overall (32.8% v 25.7%; p&lt;0.001) and in the subgroups defined by HER2 (HER2- 32.2% v 24.9%; p&lt;0.001 and HER2+ 39.9%v 30.5%; p=0.002).

Patients with PgR negative disease had a significantly worse DFS, OS, DDFS and LRFS (p&lt;0.001, respectively). Multivariable Cox regression analysis revealed that PgR was an independent prognostic factor. This was also observed in the HER2+ and- subgroups. Interestingly, in the PgR negative tumors HER2 status did not influence long-term outcome.

Conclusion

This analysis demonstrates that ER positive and PgR negative tumors represent a specific subset in primary breast cancer patients associated with higher response but also worse long term outcome after neoadjuvant chemotherapy. Interestingly, PgR negativity served as an independent predictive factor for achieving a pCR after neoadjuvant chemotherapy and therefore its status should be considered when deciding on systemic treatment.

Citation Format: van Mackelenberg M, Denkert C, Nekljudova V, Karn T, Schem C, Marme F, Stickeler E, Jackisch C, Hanusch C, Huober J, Fasching P, Blohmer J-U, Kümmel S, Müller V, Schneeweiss A, Untch M, von Minckwitz G, Weber K, Loibl S. Outcome after neoadjuvant chemotherapy in progesterone receptor negative breast cancer patients – A pooled analysis of individual patient data from ten prospectively randomized controlled neoadjuvant trials [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 P1-09-11.

Abstract P5-16-01: A randomised phase III trial comparing two dose-dense, dose-intensified approaches (ETC and PM(Cb)) for neoadjuvant treatment of patients with high-risk early breast cancer (GeparOcto)

This abstract was withdrawn by the authors.

Abstract P1-09-02: Homologous repair deficiency (HRD) as measure to predict the effect of carboplatin on survival in the neoadjuvant phase II trial GeparSixto in triple-negative early breast cancer

Introduction

Addition of carboplatin to anthracycline/taxane-based neoadjuvant chemotherapy has shown to improve pathological complete response (pCR; ypT0 ypN0) rates in patients with triple-negative breast cancer (TNBC) in two large phase II studies (GeparSixto: von Minckwitz et al, Lancet Oncol 2014, CALGB 40603: Sikov WM, J Clin Oncol 2015). Participants of the GeparSixto study showed an improvement of pCR rate from 36.9 to 53.2% (p=0.005) and DFS by absolute 9% (HR 0.56 95% CI 0.33-0.96] p=0.035) with the addition of carboplatin in the TNBC subgroup. No effect was observed in the HER2-positive subgroup. We here report results on homologous repair deficiency (HRD) status in relation to pCR and DFS in the TNBC subgroup.

Patients and Methods

In the GeparSixto trial (NCT01426880), patients were treated for 18 weeks with paclitaxel 80mg/m2 q1w and non-pegylated-liposomal doxorubicin (NPLD) 20mg/m2 q1w. Patients with TNBC (N=315) received concurrently bevacizumab 15mg/kg i.v. q2w until surgery. All patients were randomized 1:1 to receive concurrently carboplatin AUC 1.5-2 q1w vs no carboplatin. Carboplatin dose was reduced from AUC 2.0 to 1.5 by an amendment after 330 patients. Primary objective is pCR rate (ypT0 ypN0). Event free survival (EFS), and overall survival (OS) were secondary objectives. HR Deficiency status was assessed on FFPE material from pretherapeutic core biopsies. HR Deficiency was defined as either HRD score high or a BRCA mutation.

Results

HRD status was measurable in 193 of 315 TNBC patients. 101 patients of them were randomly assigned to receive carboplatin and 92 to no additional carboplatin. After median follow-up of 34.3 months 43 event free survival (EFS) events have been reported.

HR deficiency was detected in 136 (70.5%) tumors of which 79 (58.1%) showed high HRD score with intact tBRCA. HR deficiency independently predicted pCR (ypT0is ypN0) (odds ratio (OR) 2.506, CI 1.243-5.051, p=0.009). Adding carboplatin to PM significantly increased the pCR rate from 36.6% to 63.2% in HR deficient tumors with intact tBRCA (p=0.018), only marginally from 61.9% to 72.7% in BRCA mutated tumors (p=0.406), and moderately from 20.0% to 40.7% in HR non-deficient tumors (p=0.086). In general, patients with HRD deficient tumors had a better ESF than non HRD deficient ones (HR 1.805 (0.985-3.309); p=0.0526). Patients with high HRD score had an insignificant trend towards an improved EFS compared to those with low HRD score (HR 1.546 (0.764-3.127) p=0.2223). HRD deficiency did not predict carboplatin effect in patients without BRCA mutation (HR 0.8617). In multivariable analysis, only therapy, clinical nodal status before treatment, and lymphocyte predominant breast cancer were significant prognostic on EFS.

Conclusion

Within the GeparSixto study HR deficiency (either HRD score high or BRCA mutation) was associated with a higher pCR in general and an improved EFS. The effect of carboplatin could not be predicted by HR deficiency in this relatively small study. However, the results will help to understand the role of HR deficiency and the value of the HRD score in TNBC especially in patients without BRCA mutation.

Citation Format: von Minckwitz G, Timms K, Untch M, Elkin EP, Hahnen E, Fasching PA, Schneeweiss A, Salat CT, Rezai M, Blohmer J-U, Zahm D-M, Jackisch C, Gerber B, Klare P, Kümmel S, Paepke S, Schmutzler R, Chau S, Reid J, Hartman A-R, Nekljudova V, Weber KE, Loibl S. Homologous repair deficiency (HRD) as measure to predict the effect of carboplatin on survival in the neoadjuvant phase II trial GeparSixto in triple-negative 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 P1-09-02.

Perpendicular Emission, Dichroism, and Energy Dependence in Angle-Resolved Photoemission: The Importance of The Final State

Angle-resolved photoemission spectroscopy has been developed to a very high accuracy. However, effects that depend sensitively on the state of the emitted photoelectron were so far hard to compute for real molecules. We here show that the real-time propagation approach to time-dependent density functional theory allows us to obtain final-state effects consistently from first principles and with an accuracy that allows for the interpretation of experimental data. In a combined theoretical and experimental study we demonstrate that the approach captures three hallmark effects that are beyond the final-state plane-wave approximation: emission perpendicular to the light polarization, circular dichroism in the photoelectron angular distribution, and a pronounced energy dependence of the photoemission intensity.