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This abstract was withdrawn by the authors.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 P1-01-03: Dynamics of circulating tumor cells during the course of chemotherapy and prognostic relevance across molecular subtypes in high-risk early breast cancer patients – Results from the adjuvant SUCCESS A trial

Background: The presence of circulating tumor cells (CTCs) before chemotherapy is known to be associated with reduced disease free survival (DFS) and overall survival (OS) in early breast cancer (EBC). In addition, recent findings suggest that CTCs persisting after adjuvant chemotherapy indicate poor prognosis. In an explorative analysis of the SUCCESS A trial, we evaluated the prognostic relevance of changes in CTC counts during the course of adjuvant chemotherapy across molecular subtypes to assess whether the prognostic role of persisting CTCs varies according to tumor biology.

Methods: The SUCCESS A trial is a phase III study, where patients with high-risk EBC (stage pN1-3 or pT2-4 or grade 3 or age ≤ 35 or hormone-receptor negative) were randomized to adjuvant chemotherapy with 3 cycles of epirubicin-fluorouracil-cyclophosphamide followed by either 3 cycles of docetaxel or 3 cycles of gemcitabine-docetaxel. CTC enumeration was performed before and after chemotherapy using the FDA-approved CellSearch® System (Janssen Diagnostics, LLC), and CTC positivity was defined as ≥ 1 CTC in 23 ml blood. Molecular subtypes were defined as luminal A like (hormone-receptor positive, grading 1 or 2), luminal B like (hormone-receptor positive, grading 3), triple-negative or HER2-positive. Patient outcome in terms of DFS and OS was analyzed using univariate log-rank tests and Cox regression models (median follow-up time 65.2 months).

Results: Data on both molecular subtypes and CTC status before and after chemotherapy were available for 1485 (39.6%) of 3754 patients randomized. This cohort contained 577 (38.9%) luminal A like, 236 (15.9%) luminal B like, 379 (25.5%) HER2-positive and 293 (19.7%) triple negative tumors. Overall, 917 (61.8%) patients were CTC negative before and after chemotherapy (neg/neg), 260 (17.5%) patients had a negative CTC status before and a positive CTC status after chemotherapy (neg/pos), 229 (15.4%) patients converted from positive to negative CTC status (pos/neg), and 79 (5.3%) patients were positive for CTCs at both time points (pos/pos). There were significant differences in DFS and OS among these four groups in patients with luminal A like tumors (log rank test, both p < 0.003) and patients with luminal B like tumors (log rank test, both p < 0.001). In both patients with luminal A like or luminal B like tumors, persistently CTC positive patients had the worst outcome (relative to persistently CTC-negative patients) in terms of DFS and OS. In contrast to luminal-like tumors, no significant differences with regard to DFS or OS were found among the four groups (neg/neg, neg/pos, pos/neg, pos/pos) in patients with HER2-positive or triple-negative tumors (log rank test, all p > 0.13).

Conclusion: The presence of CTCs both before and after adjuvant chemotherapy was associated with poor survival in luminal A like and luminal B like tumors, but not in HER2-positive or triple-negative tumors. Further research is needed to evaluate the effect of chemotherapy on CTC prevalence in different molecular subtypes of EBC.

Citation Format: Tzschaschel MLJ, Rack B, Andergassen U, Friedl TWP, Schneeweiss A, Mueller V, Tanja F, Pantel K, Gade J, Lorenz R, Rezai M, Tesch H, Soeling U, Polasik A, Alunni-Fabbroni M, Trapp EK, Mahner S, Schindlbeck C, Lichtenegger W, Beckmann MW, Fasching PA, Janni W. Dynamics of circulating tumor cells during the course of chemotherapy and prognostic relevance across molecular subtypes in high-risk early breast cancer patients – Results from the adjuvant SUCCESS A trial [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 P1-01-03.

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.

Toxicity Assessment of a Phase III Study Evaluating FEC-Doc and FEC-Doc Combined with Gemcitabine as an Adjuvant Treatment for High-Risk Early Breast Cancer: the SUCCESS-A Trial

Introduction: This paper aims to evaluate the toxicity profile of additive gemcitabine to adjuvant taxane-based chemotherapy in breast cancer patients. Methods: Patients enrolled in this open-label randomized controlled Phase III study were treated with 3 cycles of epirubicin-fluorouracil-cyclophosphamide (FEC) chemotherapy followed by 3 cycles of docetaxel with those receiving 3 cycles of FEC followed by 3 cycles of gemcitabine-docetaxel (FEC-DG). 3690 patients were evaluated according to National Cancer Institute (NCI) toxicity criteria (CTCAE). The study medications were assessed by the occurrence of grade 3-4 adverse events, dose reductions, postponements of treatment cycles and granulocyte colony-stimulating factor (G-CSF) support. Results: No differences in neutropenia or febrile neutropenia were demonstrated. However, thrombocytopenia was significantly increased with FEC-DG treatment (2.0 vs. 0.5 %, p < 0.001), as was leukopenia (64.1 vs. 58.5 %, p < 0.001). With FEC-DG significantly more G-CSF support in cycles 4 to 6 (FEC-DG: 57.8 %, FEC-D: 36.3 %, p < 0.001) was provided. Transaminase elevation was significantly more common with FEC-DG (SGPT: 6.3 %, SGOT: 2 %), whereas neuropathy (1.2 %), arthralgia (1.6 %) and bone pain (2.6 %) were more common using FEC-D. Dose reductions > 20 % (4 vs. 2.4 %) and postponement of treatment cycles (0.9 vs. 0.4 %) were significantly more frequent in the FEC-DG arm. Eight deaths occurred during treatment in the FEC-DG arm and four in the FEC-D arm. Conclusion: The addition of gemcitabine increased hematological toxicity and was associated with more dose reductions and postponements of treatment cycles.

Impact of Age, Obesity and Smoking on Patient Satisfaction with Breast Implant Surgery - A Unicentric Analysis of 318 Implant Reconstructions after Mastectomy

Aim: Breast reconstruction has become increasingly important for the body image of women with breast cancer. We conducted a study to investigate how patient characteristics correlate with surgical outcome after breast reconstruction with implant after mastectomy and to identify risk factors which could facilitate patient selection for reconstruction. Patients and Methods: For this case cohort analysis (n = 257 patients with 318 heterologous reconstructions), we analyzed BMI, smoking, pre-existing disease, chemotherapy and radiotherapy, one-stage/two-stage reconstruction, immediate/delayed reconstruction, antibiotic therapy and complications, partner interaction and adherence to the decision for reconstruction using a customized questionnaire. Results: 257 patients with 318 implant reconstructions (196 unilateral, 61 bilateral) were eligible for inclusion in the study. Median follow-up time was 3.1 years (range: 1 month to 10 years). Response rate to the questionnaire was 71.8 %. Median age was 49 years (range 24-79 years), median BMI was 22.44 (range 16.33-40.09). A BMI > 30 was inversely correlated with positive self-image (p = 0.004), and implant loss/rotation was more frequent in this group (p < 0.05). Smoking > 10 cigarettes/day had a negative impact on surgical outcome. A positive self-image had a positive impact on partner interaction (p < 0.001) and was correlated with a lower perception of pain. Aesthetic results did not vary with age (p = 0.054). Titanized polypropylene meshes were used to protect against implant rotation (p = 0.034). Rates of capsular fibrosis were low in our cohort (< 10 %), and implant loss rate was less than 2 %. Conclusions: This study offers a differentiated approach for the pre-surgical counselling of patients and shows that patients up to 80 years of age are highly satisfied with implant reconstruction. A high BMI and smoking > 10 cigarettes/day are unfavorable preconditions for implant reconstruction. The use of prophylactic antibiotics was confirmed as beneficial for surgical outcome. A positive self-image after reconstruction strongly influences partner interaction.

Translating the concept of intrinsic subtypes into an oncoplastic cohort of more than 1000 patients - predictors of recurrence and survival

INTRODUCTION

A paradigm shift in breast cancer was introduced by Sørlie's concept of intrinsic subtypes [1]. We validated this concept - which was originally based on 84 individuals - in a large cohort study of 1035 patients with oncoplastic surgery and analyzed if early and late recurrences are linked to a specific intrinsic tumor subtype or resection margins.

MATERIALS AND METHODS

1035 patients with oncoplastic surgery (2004-2009) were analyzed with regard to treatment characteristics and patterns of early (<5 years) and late recurrence (>5 years) and survival related to the intrinsic subtypes. Data was retrieved from patient's charts, customized patients questionnaires and cancer registries.

RESULTS

944 patients with primary, unilateral breast cancer, median age 58 years, were eligible for analysis. At a median FU of 5.2 years, LRR was 4.0%, 5-year-OS 94.5% and DFS 90.9%. Intrinsic subtypes, but not T-size, nodal-status, resections margins nor histopathology, governed local control and survival. There was no signal for prevelance of unclear margins in any of intrinsic subgroups and no preference of any oncoplastic technique attributed to them. TNBC and Her2 non-luminal breast cancer had highest recurrence and lowest survival rates. Although sentinel involvement (SLN+) was prevailing in the Luminal-B-Her 2 negative subtype at 34.3%, this did not translate into a higher axillary dissection rate.

CONCLUSION

This study confirmed the intrinsic subtype concept on a large clinical basis and describes the patterns of early and late recurrence in oncoplastic surgery, concluding that bigger risk may not be overcome by bigger surgery.

Evaluation of Therapy Management and Patient Compliance in Postmenopausal Patients with Hormone Receptor-positive Breast Cancer Receiving Letrozole Treatment: The EvaluateTM Study

Introduction: The EvaluateTM study (Evaluation of therapy management and patient compliance in postmenopausal hormone receptor-positive breast cancer patients receiving letrozole treatment) is a prospective, non-interventional study for the assessment of therapy management and compliance in the routine care of postmenopausal women with invasive hormone receptor-positive breast cancer receiving letrozole. The parameters for inclusion in the study are presented and discussed here. Material and Methods: Between January 2008 and December 2009 a total of 5045 patients in 310 study centers were recruited to the EvaluateTM study. Inclusion criteria were hormone receptor-positive breast cancer and adjuvant treatment or metastasis. 373 patients were excluded from the analysis for various reasons. Results: A total of 4420 patients receiving adjuvant treatment and 252 patients with metastasis receiving palliative treatment were included in the study. For 4181 patients receiving adjuvant treatment, treatment with the aromatase inhibitor letrozole commenced immediately after surgery (upfront). Two hundred patients had initially received tamoxifen and started aromatase inhibitor treatment with letrozole at 1-5 years after diagnosis (switch), und 39 patients only commenced letrozole treatment 5-10 years after diagnosis (extended endocrine therapy). Patient and tumor characteristics were within expected ranges, as were comorbidities and concurrent medication. Conclusion: The data from the EvaluateTM study will offer a good overview of therapy management in the routine care of postmenopausal women with hormone receptor-positive breast cancer. Planned analyses will look at therapy compliance and patient satisfaction with how information is conveyed and the contents of the conveyed information.

Survival after neoadjuvant chemotherapy with or without bevacizumab or everolimus for HER2-negative primary breast cancer (GBG 44-GeparQuinto)†

BACKGROUND

The GeparQuinto study showed that adding bevacizumab to 24 weeks of anthracycline-taxane-based neoadjuvant chemotherapy increases pathological complete response (pCR) rates overall and specifically in patients with triple-negative breast cancer (TNBC). No difference in pCR rate was observed for adding everolimus to paclitaxel in nonearly responding patients. Here, we present disease-free (DFS) and overall survival (OS) analyses.

PATIENTS AND METHODS

Patients (n = 1948) with HER2-negative tumors of a median tumor size of 4 cm were randomly assigned to neoadjuvant treatment with epirubicin/cyclophosphamide followed by docetaxel (EC-T) with or without eight infusions of bevacizumab every 3 weeks before surgery. Patients without clinical response to EC ± Bevacizumab were randomized to 12 weekly cycles paclitaxel with or without everolimus 5 mg/day. To detect a hazard ratio (HR) of 0.75 (α = 0.05, β = 0.8) 379 events had to be observed in the bevacizumab arms.

RESULTS

With a median follow-up of 3.8 years, 3-year DFS was 80.8% and 3-year OS was 89.7%. Outcome was not different for patients receiving bevacizumab (HR 1.03; P = 0.784 for DFS and HR 0.974; P = 0.842 for OS) compared with patients receiving chemotherapy alone. Patients with TNBC similarly showed no improvement in DFS (HR = 0.99; P = 0.941) and OS (HR = 1.02; P = 0.891) when treated with bevacizumab. No other predefined subgroup (HR+/HER2-; locally advanced (cT4 or cN3) or not; cT1-3 or cT4; pCR or not) showed a significant benefit. No difference in DFS (HR 0.997; P = 0.987) and OS (HR 1.11; P = 0.658) was observed for nonearly responding patients receiving paclitaxel with or without everolimus overall as well as in subgroups.

CONCLUSIONS

Long-term results, in opposite to the results of pCR, do not support the neoadjuvant use of bevacizumab in addition to an anthracycline-taxane-based chemotherapy or everolimus in addition to paclitaxel for nonearly responding patients.

CLINICAL TRIAL NUMBER

NCT 00567554, www.clinicaltrials.gov.

Abstract S5-05: Postneoadjuvant treatment with zoledronate in patients with tumor residuals after anthracyclines-taxane-based chemotherapy for primary breast cancer – The phase III NATAN study (GBG 36/ABCSG XX)

Background: Patients with residual disease after neoadjuvant chemotherapy (NACT) are considered to have chemoresistant breast cancer. Adjuvant treatment with bisphosphonates is considered to reduce the relapse risk predominantly in estrogen-deprivated patients.

Methods: Patients who had invasive tumor residuals (ypT1-4 or ypN+) after a minimum of 4 cycles of anthracycline-taxane-containing NACT were eligible to the NATAN study. Patients were randomized within 3 years after surgery to receive zoledronate 4 mg i.v. (plus 1000 mg Ca2+ and 880 I.U. vitamin D daily) for 5 years vs. observation. Zoledronate was given q 4 weeks for the first 6 months, q 3 months the following 2 years, and q 6 months for the last 2.5 years. Patients with hormone receptor (HR)-positive disease received letrozole for 5 years if postmenopausal, or tamoxifen, if premenopausal. Adjuvant trastuzumab for HER2-positive disease was allowed since an amendment in 2007. Stratification factors were HR, time since surgery, age, and center. Primary objective was event-free survival (EFS). 654 patients and 316 events were required to observe an increase of 5yr EFS from 58% to 67.2% (hazard ratio 0.73). Secondary objectives were to determine overall survival, EFS with respect to the interval between surgery and randomization, bone-metastasis-free-survival, toxicity of and compliance to zoledronate, the predictive value of breast tumor response to NACT on the effect of postoperative treatment and the prognostic impact of chemotherapy induced amenorrhea in premenopausal patients. An interim analysis for high efficacy at 158 observed events was planned in the protocol; in agreement with study IDMC a Bayesian analysis for futility with futility boundary of 15% will be performed at the same time.

Results: Between 2/2005 and 5/2009 693 patients were enrolled. Time between surgery and randomization was &lt;4 months in 48.4%, 4-12 months in 34.5%, and 13-36 months in 17.1% of patients. The median age was 50.9 yrs (range 33.7-88.2), 72.3% of patients were postmenopausal. 82% had HR-positive and 19% HER2-positive disease. During a median follow up of 48 months 154 events were observed so far.

Conclusion: This is the first post-neoadjuvant phase III study. Analysis of the primary endpoint will be presented in case the IDMC will release of the results of the futility analysis.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr S5-05.

Abstract P6-06-23: Glycogen-rich, clear cell breast cancer - An underestimated histopathological risk factor?

Introduction:

Glycogen-rich clear cell carcinoma (GRCCC) is a rare tumour and there is only few data on the prognosis of this subtype, the largest cases series ever published in literature comprising of 21 cases only. (1)

Patients and methods:

In a case-control study of 56 GRCCC early breast cancer cases with matched pairs we analyzed the features of this subtype and survival data regarding DFS and OS.

56 patients with GRCCC have been identified from the period 1992 until 2010 in a multicenter retrospective case cohort trial. To determine the incidence of glycogen-rich clear cell carcinoma in various age groups were stratified in 3 age groups: &lt; 45 years, &lt; 65 years and &gt; 65 years. This was compared to incidence of all breast cancer subtypes due to epidemiological data of Robert-Koch-Institute of the German Ministry of Health.

Results:

Patients were in a range of 33-87 years, median 59,5 years, distributed to the following age groups: 14% (n = 8) of patients were &lt; 45 years, 71,4% (n = 40) &lt; 65 years and 28,6% (n = 16) &gt; 65 years. In the epidemiological data set 10% were &lt; 45 years, 50% &lt; 65 years and 50% &gt; 65 years. Thus patients with glycogen-rich clear cell carcinoma were younger compared to the epidemiological data of all breast cancers registered nationally (&lt; 65 years: 71,4% vs. 50%; p &lt; 0,002).

Stage distribution was as follows: Stage T1 a: no cases, T1b: 2, T1c: 19, T2: 20, T3: 4, T4: 4, unknown T-stage in 7 cases.

Nodal status was in 22 nodal-positive, 23 nodal-negative and 11 with unknown nodal status. The Grading was in G1 none, G2 24 and G3 29 and unknown in 3 cases. Approximated intrinsic tumour subtype was: Luminal A: 10, Luminal B 3, Luminal Her2 positive 16, non-luminal Her2 negative: 14, Triple-Negative Breast Cancer: 7; not further specified: 6.

Chemotherapy was applied in 35 out of 56 patients (62,5%) in our study cohort.

5-years-(OS) was 84% and 5-years (DFS) was 80%. Recurrence rates at a mean time of follow-up of 8,5 years were significantly higher (11 recurrences out of 56 cases) in this specific subtype than in the matched control group (p&lt;0,005).

OS was significantly lower in the group with a local recurrence, dropping down from a 5-years OS-rate of 92% in the recurrence-free group to 48% in the group with a loco-regional recurrence.

Conclusion:

GRCCC of the breast is associated with a highly proliferative and aggressive receptor profile and unfavourable course of disease with significantly higher risk of recurrence (p&lt; 0,005).

This is - to our best knowledge - the largest cohort published in literature on this rare histological subtype of human early breast cancer. Evidence derived from this analysis suggests effective chemotherapy treatment to reduce the risk of recurrence and mortality from this aggressive tumour subtype.

The poor prognosis of 48% in 5-years-overall-survival in case of a loco-regional recurrences of glycogen-rich clear cell carcinom also endorses a role of chemo-therapy in case of recurrence, with regards to the fact that survival rates in this tumor subtype of our cohort were even lower than in the cohort of the CALOR trial.(2)

Literature:

1) Hayes MMM, Am J Surg Pathol. 1995;19:904-911.

2)Aebi S, S3-2. San Antonio Breast Cancer Symposium 2012.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-06-23.

Abstract P3-14-01: Features of neoadjuvant and adjuvant chemotherapy in breast cancer – A population-based study on 39404 patients

Background: Neoadjuvant chemotherapy (NACT) is increasingly used globally in clinical trials for breast cancer patients. In Germany, NACT has been implemented as a standard option of care for almost a decade. In a population-based benchmark cohort study, the West German Breast Center (WBC) recorded approximately 50% of all breast cancer cases diagnosed in Germany between 2007 and 2010. We compare baseline and treatment pattern of patients treated either with adjuvant (ACT) or NACT.

Methods: Approx. 200 accredited breast centers treated 115169 primary breast cancer patients of whom 32609 received ACT and 6795 NACT. Pathological complete response (pCR) was stated if no invasive and no non-invasive tumor residues (ypT0 ypN0) were detected. Follow up information was available for 55% of patients.

Results: Use of NACT increased from 16.4% in 2007 to 19.1% in 2010 (p&lt;.0001). Patients treated with NACT were younger, had higher clinical nodal involvement, fewer lobular-invasive cancers, more undifferentiated, hormone-receptor-negative, and HER2-positive cancers, and more multicentric tumors compared to patients treated with ACT (all p&lt;0.002). 34% of patients in the NACT group had cT3/4 tumors compared to 7.7% of pT3/4 tumors in the ACT group. cN0 status was twice as frequent (70.6% vs 37.7%, p&lt;.0001) whereas pN0 status was reported less frequently (47.4% vs 51.4%, p&lt;0.0001) in the ACT and NACT group, respectively. Time between diagnosis and start of systemic treatment or surgery was in median 12 (range 1-902) and 22 (range 1-721) days in the ACT and NACT group, respectively (p&lt;.0001). 66.2% and 91.4% of patients received ACT and NACT with a taxane, respectively (p&lt;.0001). 9.7% and 37.5% of patients receiving treatment for &gt; = 18 weeks, respectively. 35.2% and 69.9% of patients with HER2-positive tumors received adjuvant or neoadjuvant trastuzumab, respectively (p&lt;.0001). 21.7% and 31.4% of patients were treated in ACT or NACT clinical trials, respectively (p&lt;.0001). Breast conservation was possible in 69.4% and 55.2% in the ACT and NACT group, respectively (p&lt;.0001). 30.5% and 37.5% needed two or more surgical interventions in the ACT and NACT group, respectively (p&lt;.0001).

Multivariable logistic regression analysis confirmed taxane- and trastuzumab-based treatment, study participation, age, histologic type, grading, and hormone-receptor status as independent predictors of pCR. pCR rate was not dependent on the time between diagnosis and start of treatment or the time between end of chemotherapy and surgery.

In univariate analysis patients receiving NACT showed a 4-year overall survival rate of 78%, compared to 92% in patients receiving ACT (p&lt;.0001). However, patients with a pCR after NACT showed a comparable survival to patients in the ACT group, whereas patients without a pCR showed a 4-year overall survival rate of 76%. In the hormone-receptor-positive/HER2-positive and even more in the triple-negative subgroup, survival of patients with a pCR appeared better than in patients with ACT.

Conclusion: In this population-based study, NACT was used in patients with unfavorable risk factors and was more intense than ACT. Outcome of patients with pCR after NACT was similar and in aggressive tumor subtypes even better than after ACT.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-14-01.

Abstract P3-14-04: The choice of the indicator lesion impacts on the pCR rate – An analysis of 114 bilateral breast cancer patients treated within neoadjuvant trials

Background: Patients with bilateral breast cancer are usually excluded from participating in clinical trials. The German Breast Group has traditionally included these patients into their neoadjuvant trials. However, little is known about the outcome of the non-indicator lesion.

Methods: We prospectively captured the information on bilateral breast cancer in our database and collected retrospectively the information from the original histological and surgical reports on tumor size, nodal status, histology, grading, hormone receptor and HER2 status as well as type of surgery and pathological complete response defined as ypT0 ypN0 and ypT0/is ypN0 because both definitions have been used in our clinical studies. The treating physician decided on clinical presentation, which side to be the indicator lesion on which response was assessed for the purpose of the study. The synchronous carcinoma in the contralateral breast is considered as the non-indicator lesion.

Results: From the 6727 patients treated within the Gepartrio, Geparquattro, Geparquinto, and Geparsixto study 157 (2.3%) patients have been identified with the diagnosis of bilateral carcinoma. From the 114 bilateral patients with any information on the non indicator lesion 104 with information on pCR on both sides were used for further analysis. The median age was 51 (range 29-74) years. There were more cT1 (48.5% vs 9.6%, p&lt;0.001) and cN0 (60.0% vs 38.4%, p = 0.004) tumors in the group of the non-indicator lesion compared to the indicator lesion group. In 56% the molecular subtype was identical 86% had a luminal A like tumor of indicator as well as the non-indicator lesion, none of the luminal B-like indicator lesions were identical, 27% of the HER2+/ HR +, 58% in the HER2+/ HR- group and 66% of the triple negative indicator lesions had an identical non indicator lesion. In general the tumor tended to be of lower malignant potential in the non- indicator lesion. Lobular carcinomas (23.4% vs 16.7%, p = 0.205); grade 3 (26% vs 36.7%, p = 0.101), ER positive (72% vs 67%, p = 0.427), HER2-positive (23.9 vs. 35.7%, p = 0.068). Overall the pCR rate (ypT0 ypN) was 20.2% in the non-indicator lesion group vs 13.9% the indicator lesion group (p = 0.276) and ypT0/is ypN0 was 30.8% and 17.6%, respectively (p = 0.0388). 64.4% had no pCR in the indicator as well as the non-indicator lesion, 11.5% had a pCR in the indicator as well as the non-indicator lesion, 4.8% in the indicator alone and 19.2% in the non-indicator alone. Breast conserving surgery was performed more often for non-indicator lesions than for indicator lesions (59% vs 44.4%, p = 0.144).

Conclusion: In general the selection for the indicator lesion was based on tumor size, nodal status and inclusion criteria. Probably, some of the indicator lesions would not have qualified for trial participation. The pCR rate including non-invasive residuals was significantly higher for the non-indicator lesions probably due to smaller tumors and less nodal involvement at baseline. However, based on our data bilateral breast carcinomas should not be excluded from neoadjuvant clinical trials.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-14-04.

Abstract P6-05-11: Run-in phase of prospective WSG-ADAPT HR+/HER2- trial demonstrates feasibility of early endocrine sensitivity prediction by recurrence score and conventional parameters in clinical routine

Background: Despite promising evidence regarding outcome prediction, endocrine sensitivity, as determined by proliferation response to short-term preoperative endocrine therapy, is currently not included in adjuvant chemotherapy decisions in early HR+/HER2- breast cancer (BC).

Methods: The prospective WSG-ADAPT HR+/HER2- trial includes early BC patients with 0-3 positive LN who are candidates for adjuvant chemotherapy based on clinical-pathological criteria alone; it aims to spare chemotherapy in a substantial proportion utilizing a combination of genomic assessment by Oncotype DX and endocrine sensitivity testing. All patients received 3-week preoperative endocrine induction therapy (ET): aromatase inhibitors (AI) if postmenopausal, tamoxifen if premenopausal. Patients with low (0-11) Recurrence Score (RS) or intermediate RS (12-25) and ET response (centrally tested, post-therapy Ki-67 &lt;10%) are recommended to forego adjuvant chemotherapy (“low-risk” patients). Distribution of RS, responder percentages in each group, and impacts of RS, ET regimen, and initial Ki-67 on post-therapy Ki-67 are reported here.

Results: As of 6/2013, 380 patients from 30 study centers had been enrolled in the ADAPT HR+/HER2- trial. Median age was 54 years. At first pre-planned analysis (5/2013), paired Ki-67 measurements (pre-/post-therapy) were available in 241 patients; RS was available in 208 cases (201 with paired Ki-67). RS was low in 21.6%, intermediate in 57.7%, and high in 20.7%; the respective risk group responder percentages (post-treatment Ki 67 &lt;10%) were 84.1%, 73.9%, and 40.0% (p&lt;0.001 when comparing low/intermediate vs. high, chi-square). In particular, these percentages support the pre-trial estimate of &gt;70% endocrine responders in the intermediate genomic risk group, who could potentially be spared adjuvant chemotherapy. Median Ki 67 level decreases (as percentage of pre-treatment value) were 25% in premenopausal patients (tamoxifen, n = 101) vs. 75% in postmenopausal patients (AI, n = 115) (p&lt;0.001, Mann-Whitney); median decreases by RS group were similar, 61% (low), 53% (intermediate) and 56% (high), respectively (p = 0.81, Kruskal-Wallis). In linear regression, pre-treatment Ki-67, endocrine regimen/menopausal status, and RS were all independent predictors for post-treatment Ki 67. Final run-in-phase analysis and validation will be presented after completion of endocrine induction therapy in 400 patients.

Conclusions: The Run-In Phase of the WSG ADAPT HR+/HER2- trial confirms trial design estimates of RS and proliferation response to induction ET. It indicates that the multicenter prospective ADAPT concept combining static and dynamic biomarker assessment for individualized therapy decisions in early BC is feasible. Proliferation response was strongly associated with therapy group (AI/post-menopausal vs. tamoxifen/pre-menopausal). Survival non-inferiority of intermediate Recurrence Score proliferation responders vs. low Recurrence Score patients (active control) will be tested in the ADAPT main phase to determine if adjuvant chemotherapy can be spared in 70% of patients with 0-3 positive LN classified as “intermediate risk” by conventional factors.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-05-11.

Survival after adding capecitabine and trastuzumab to neoadjuvant anthracycline-taxane-based chemotherapy for primary breast cancer (GBG 40--GeparQuattro)

BACKGROUND

The GeparQuattro study showed that adding capecitabine or prolonging the duration of anthracycline-taxane-based neoadjuvant chemotherapy from 24 to 36 weeks did not increase pathological complete response (pCR) rates. Trastuzumab-treated patients with HER2-positive disease showed a higher pCR rate than patients with HER2-negative disease treated with chemotherapy alone. We here present disease-free (DFS) and overall survival (OS) analyses.

PATIENTS AND METHODS

Patients (n = 1495) with cT ≥ 3 tumors, or negative hormone-receptor status, or positive hormone-receptor and clinically node-positive disease received four times epirubicin/cyclophosphamide and were thereafter randomly assigned to four times docetaxel (Taxotere), or four times docetaxel/capecitabine over 24 weeks, or four times docetaxel followed by capecitabine over 36 weeks. Patients with HER2-positive tumors received 1 year of trastuzumab, starting with the first chemotherapy cycle. Follow-up was available for a median of 5.4 years.

RESULTS

Outcome was not improved for patients receiving capecitabine (HR 0.92; P = 0.463 for DFS and HR 93; P = 0.618 for OS) as well as for patients receiving 36 weeks of chemotherapy (HR 0.97; P = 0.818 for DFS and HR 0.97; P = 0.825 for OS). Trastuzumab-treated patients with HER2-positive disease showed similar DFS (P = 0.305) but a significantly better adjusted OS (P = 0.040) when compared with patients with HER2-negative disease treated with chemotherapy alone. Recorded long-term cardiac toxicity was low.

CONCLUSIONS

Long-term results, similar to the results of pCR, do not support the use of capecitabine in the neoadjuvant setting in addition to an anthracycline-taxane-based chemotherapy. However, the results support previous data showing a benefit of trastuzumab as predicted by higher pCR rates.

Neoadjuvant bevacizumab and anthracycline-taxane-based chemotherapy in 678 triple-negative primary breast cancers; results from the geparquinto study (GBG 44)

BACKGROUND

We evaluated the pathological complete response (pCR) rate after neoadjuvant epirubicin, (E) cyclophosphamide (C) and docetaxel containing chemotherapy with and without the addition of bevacizumab in patients with triple-negative breast cancer (TNBC).

PATIENTS AND METHODS

Patients with untreated cT1c-4d TNBC represented a stratified subset of the 1948 participants of the HER2-negative part of the GeparQuinto trial. Patients were randomized to receive four cycles EC (90/600 mg/m(2); q3w) followed by four cycles docetaxel (100 mg/m(2); q3w) each with or without bevacizumab (15 mg/kg; q3w) added to chemotherapy.

RESULTS

TNBC patients were randomized to chemotherapy without (n = 340) or with bevacizumab (n = 323). pCR (ypT0 ypN0, primary end point) rates were 27.9% without and 39.3% with bevacizumab (P = 0.003). According to other pCR definitions, the addition of bevacizumab increased the pCR rate from 30.9% to 41.8% (ypT0 ypN0/+; P = 0.004), 36.2% to 46.4% (ypT0/is ypN0/+; P = 0.009) and 32.9% to 43.3% (ypT0/is ypN0; P = 0.007). Bevacizumab treatment [OR 1.73, 95% confidence interval (CI) 1.23-2.42; P = 0.002], lower tumor stage (OR 2.38, 95% CI 1.24-4.54; P = 0.009) and grade 3 tumors (OR 1.68, 95% CI 1.14-2.48; P = 0.009) were confirmed as independent predictors of higher pCR in multivariate logistic regression analysis.

CONCLUSIONS

The addition of bevacizumab to chemotherapy in TNBC significantly increases pCR rates.