Nab-paclitaxel weekly versus dose-dense solvent-based paclitaxel followed by dose-dense epirubicin plus cyclophosphamide in high-risk HR+/HER2- early breast cancer: results from the neoadjuvant part of the WSG-ADAPT-HR+/HER2- trial

BACKGROUND

In high-risk hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) early breast cancer (EBC), nanoparticle albumin-bound (nab)-paclitaxel showed promising efficacy versus solvent-based (sb)-paclitaxel in neoadjuvant trials; however, optimal patient and therapy selection remains a topic of ongoing research. Here, we investigate the potential of Oncotype DX® recurrence score (RS) and endocrine therapy (ET) response (low post-endocrine Ki67) for therapy selection.

PATIENTS AND METHODS

Within the WSG-ADAPT trial (NCT01779206), high-risk HR+/HER2- EBC patients were randomized to (neo)adjuvant 4× sb-paclitaxel 175 mg/m2 q2w or 8× nab-paclitaxel 125 mg/m2 q1w, followed by 4× epirubicin + cyclophosphamide (90 mg + 600 mg) q2w; inclusion criteria: (i) cN0-1, RS 12-25, and post-ET Ki67 >10%; (ii) cN0-1 with RS >25. Patients with cN2-3 or (G3, baseline Ki67 ≥40%, and tumor size >1 cm) were allowed to be included without RS and/or ET response testing. Associations of key factors with pathological complete response (pCR) (primary) and survival (secondary) endpoints were analyzed using statistical mediation and moderation models.

RESULTS

Eight hundred and sixty-four patients received neoadjuvant nab-paclitaxel (n= 437) or sb-paclitaxel (n = 427); nab-paclitaxel was superior for pCR (20.8% versus 12.9%, P = 0.002). pCR was higher for RS >25 versus RS ≤25 (16.0% versus 8.4%, P = 0.021) and for ET non-response versus ET response (15.1% versus 6.0%, P = 0.027); no factors were predictive for the relative efficacy of nab-paclitaxel versus sb-paclitaxel. Patients with pCR had longer distant disease-free survival [dDFS; hazard ratio 0.42, 95% confidence interval (CI) 0.20-0.91, P = 0.024]. Despite favorable prognostic association of RS >25 versus RS ≤25 with pCR (odds ratio 3.11, 95% CI 1.71-5.63, P ≤ 0.001), higher RS was unfavorably associated with dDFS (hazard ratio 1.03, 95% CI 1.01-1.05, P = 0.010).

CONCLUSIONS

In high-risk HR+/HER2- EBC, neoadjuvant nab-paclitaxel q1w appears superior to sb-paclitaxel q2w regarding pCR. Combining RS and ET response assessment appears to select patients with highest pCR rates. The disadvantage of higher RS for dDFS is reduced in patients with pCR. These are the first results from a large neoadjuvant randomized trial supporting the use of RS to help select patients for neoadjuvant chemotherapy in high-risk HR+/HER2- EBC.

Prevalence of Pathogenic Germline Variants in Women with Non-Familial Unilateral Triple-Negative Breast Cancer

INTRODUCTION

International guidelines recommend genetic testing for women with familial breast cancer at an expected prevalence of pathogenic germline variants (PVs) of at least 10%. In a study sample of the German Consortium for Hereditary Breast and Ovarian Cancer (GC-HBOC), we have previously shown that women with TNBC diagnosed before the age of 50 years but without a family history of breast or ovarian cancer (sTNBC) meet this criterion. The present study investigates the PV prevalence in BRCA1, BRCA2, and nine additional cancer predisposition genes in an extended sTNBC study sample including a cohort of women with a later age at sTNBC diagnosis.

PATIENTS AND METHODS

In 1,600 women with sTNBC (median age at diagnosis: 41 years, range 19-78 years), we investigated the association between age at diagnosis and PV occurrence in cancer predisposition genes using logistic regression.

RESULTS

260 sTNBC patients (16.2%) were found to have a PV in cancer predisposition genes (BRCA1: n = 170 [10.6%]; BRCA2: n = 46 [2.9%], other: n = 44 [2.8%]). The PV prevalence in women diagnosed between 50 and 59 years (n = 194) was 11.3% (22/194). Logistic regression showed a significant increase in PV prevalence with decreasing age at diagnosis (OR 1.41 per 10 years younger age at diagnosis; 95% confidence interval: 1.21-1.65; p < 0.001). The PV prevalence predicted by the model was above 10% for diagnoses before the age of 56.8 years.

CONCLUSION

Based on the data presented, we recommend genetic testing by gene panel analysis for sTNBC patients diagnosed before the age of 60 years. Due to the still uncertain estimate for women with sTNBC diagnosed above the age of 60 years, further studies are needed.

Preservation of the mesureter to reduce urinary complications: analysis of data from the observational Leipzig School MMR study

OBJECTIVE

To evaluate the feasibility and effect of mesureteral preservation on urinary complications in the context of total mesometrial resection (TMMR), a surgical treatment for cervical cancer.

DESIGN

Retrospective cohort study with historic control.

SETTING

Single tertiary academic centre.

POPULATION

Women older than 18 with primary cervical cancer staged FIGO IB1-IIB enrolled in the prospective Leipzig School MMR study and underwent total mesometrial resection (TMMR) without adjuvant radiation.

METHOD

We retrospectively analysed 100 consecutive TMMR procedures which were performed for cancer of the uterine cervix and in which the mesureter was preserved (intervention group, 01/2014-06/2017). We compared this group with the previous 100 consecutive TMMRs, which were performed before the introduction of mesureteral preservation (control group, 09/2010-01/2014).

MAIN OUTCOME MEASURES

The occurrence of urological and specifically ureteral complications.

RESULTS

Mesureteral preservation was feasible and was associated with a significant decrease in ureteral complications (11% without mesureteral preservation versus 3% with mesureteral preservation, P = 0.049). Furthermore, we found a significant decrease in the number of postoperative percutaneous nephrostomies and re-operations (7% versus none, P = 0.014). There was also a trend towards a decrease in other urinary complications such as postoperative bladder atony and uretero-vaginal fistulas.

CONCLUSION

The mesureter constitutes a convenient dissection plane enabling the preservation of lateral ureteral blood supply during TMMR. In our study, maintenance of mesureteral integrity was associated with a significant reduction in ureteral complications. Mesureteral preservation might also be useful in other types of pelvic surgeries that carry a high risk of ureteral damage.

TWEETABLE ABSTRACT

Surgical preservation of the mesureter in cervical cancer patients was associated with a reduction in urinary complications.

Evaluating the addition of bevacizumab to endocrine therapy as first-line treatment for hormone receptor-positive metastatic breast cancer: a pooled analysis from the LEA (GEICAM/2006-11_GBG51) and CALGB 40503 (Alliance) trials

BACKGROUND

Randomised trials comparing the efficacy of standard endocrine therapy (ET) versus experimental ET + bevacizumab (Bev) in 1st line hormone receptor-positive patients with metastatic breast cancer have thus far shown conflicting results.

PATIENTS AND METHODS

We pooled data from two similar phase III randomised trials of ET ± Bev (LEA and Cancer and Leukemia Group B 40503) to increase precision in estimating treatment effect. Primary end-point was progression-free survival (PFS). Secondary end-points were overall survival (OS), objective response rate (ORR), clinical benefit rate (CBR) and safety. Exploratory analyses were performed within subgroups defined by patients with recurrent disease, de novo disease, prior endocrine sensitivity or resistance and reported grades III-IV hypertension and proteinuria.

RESULTS

The pooled sample consisted of 749 patients randomised to ET or ET + Bev. Median PFS was 14.3 months for ET versus 19 months for ET + Bev (unadjusted hazard ratio [HR] 0.77; 95% confidence interval [CI] 0.66-0.91; p < 0.01). ORR and CBR with ET and ET + Bev were 40 versus 61% (p < 0.01) and 64 versus 77% (p < 0.01), respectively. There was no difference in OS (HR 0.96; 95% CI 0.77-1.18; p = 0.68). PFS was superior for ET + Bev for endocrine-sensitive patients (HR 0.68; 95% CI 0.53-0.89; p = 0.004). Grade III-IV hypertension (2.2 versus 20.1%), proteinuria (0 versus 9.3%), cardiovascular (0.5 versus 4.2%) and liver events (0 versus 2.9%) were significantly higher for ET + Bev (all p < 0.01). Hypertension and proteinuria were not predictors of efficacy (interaction test p = 0.33).

CONCLUSION

The addition of Bev to ET increased PFS overall and in endocrine-sensitive patients but not OS at the expense of significant additional toxicity.

TRIALS REGISTRATION

ClinicalTrial.Gov NCT00545077 and NCT00601900.

Abstract GS5-06: No survival benefit of chemotherapy escalation in patients with pCR and “high-immune” triple-negative early breast cancer in the neoadjuvant WSG-ADAPT-TN trial

Background:Immune markers such as tumor infiltrating lymphocytes (TILs), CD8, PDL1, PD1 and other protein or mRNA-based genomic markers have been identified as prognostic / predictive in TNBC regarding survival / chemotherapy (CTx) efficacy.

In the adjuvant WSG-PlanB trial, patients with high TILs and/or CD8 by mRNA had excellent outcome, irrespective of anthracycline use; in the neoadjuvant ADAPT-TN trial, high PDL1, PD1 and CD8 and/or TILs were predictive for pCR. Still, optimal markers for potential treatment de-escalation have yet to be determined. Here, we analyse for the first time impact of immune mRNA-based markers and TIL's as prognostic and predictive survival markers.

Methods: TNBC patients (ER/PR&lt;1%, HER2-,) were randomized to neoadjuvant 4x nab-paclitaxel 125 mg/m2/gemcitabine 1000 mg/m2 d1/8 q3w (gem arm) or 4x nab-paclitaxel 125 mg/m2/carboplatin AUC2 day 1/8 3-weekly (q3w) (carbo arm). Primary endpoint of WSG-ADAPT-TN was pCR (ypT0/is/ypN0); secondary endpoints included translational analyses, e.g., TILs or expression of 119 genes by nCounter platform. Standard adjuvant chemotherapy (4xEC) was optional (not randomized) in patients achieving pCR after 12 weeks. According to protocol, 1st safety survival analysis was performed after 3y median follow-up.

Results: Present translational analysis included 306 of 336 TNBC patients (36 months median FU). pCR was associated with significantly better survival (3y EFS: 92% vs. 71%, p&lt;.001), but despite substantially higher pCR in the carbo arm (46% vs. 29%), no significant EFS advantage was seen (p=.6) (gem: 78%; carbo: 80%; 3y-EFS).

Bivariate Spearman correlations among CD8, PD1, and PDL1 were strongly positive; their correlations with TILs were moderately positive.

Preliminary Cox analysis of EFS was performed with clinical variables (cN, cT, menopausal status); neoadjuvant study arm; pCR; TILs; proliferation markers (baseline Ki67 by IHC, scores derived from PAM50); baseline immune markers; risk scores; and individual gene expression scores previously identified as prognostic for pCR in one or both neoadjuvant arms. Independent prognostic factors included pCR, cN, Ki67, PD1, and CD8; these were entered into (prognostic) interaction analysis. The resulting model contained cN, high Ki67 and low TILs as (unfavorable) main effects and the interaction of (higher) PD1*pCR (favorable).

Among pCR patients, the groups with/without additional adjuvant CTX were similar with respect to explanatory factors. Baseline TILs, Ki67, cN, and PD1 were entered into exploratory predictive analysis; the model retained only the interaction [adjuvant CTx * (fractionally ranked) PD1]. In patients with pCR, those with low PD1 benefited from standard anthracycline-containing adjuvant CTx, whereas patients high PD1 did not with an 98% 3y-EFS.

Conclusions: Our exploratory results suggest independent prognostic impact of mRNA markers and TIL's in early TNBC. Patients with both pCR (after 12 weeks) and “high-immune” signature (defined here by PD1) had excellent 3y-EFS and may be candidates for treatment de-escalation (e.g. omission of anthracyclines), whereas “low-immune” pCR patients may benefit from standard adjuvant poly-chemotherapy.

Citation Format: Gluz O, Nitz U, Liedtke C, Prat A, Christgen M, Feuerhake F, Garke M, Grischke E-M, Forstbauer H, Braun M, Warm M, Hackmann J, Uleer C, Aktas B, Schumacher C, Kuemmel S, Pelz E, Gebauer D, Paré L, Kates R, Wuerstlein R, Kreipe HH, Harbeck N. No survival benefit of chemotherapy escalation in patients with pCR and “high-immune” triple-negative early breast cancer in the neoadjuvant WSG-ADAPT-TN trial [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 GS5-06.

Abstract PD3-02: Comparison of HER2, estrogen and progesterone receptor expression profiles of primary tumor, synchronous axillary lymph node metastases and circulating tumor cells in early breast cancer patients

Background:Targeted systemic therapy in early breast cancer with synchronous lymph node metastasis is currently based on the expression of the hormone receptors (ER/PR ≥1%) and overexpression of HER2 in the primary tumor. However, the expression of these predictive markers on lymph node metastases as well as on circulating tumor cells (CTCs), the precursors of metastatic disease, has not yet been taken into account. The aim of the present study was to compare the HER2/ER/PR expression profiles of primary tumors, synchronous lymph node metastases and circulating tumor cells in early breast cancer patients and relate the results to 5-year overall (OS) and disease-free survival (DFS).

Patients and Methods:76 patients with early breast cancer diagnosed between 2006 and 2010 were enrolled in this study. Blood was obtained at the time of first diagnosis of disease and analyzed for CTCs using the AdnaTest BreastCancer (Qiagen Hannover GmbH) for the expression of EpCAM, MUC-1, HER2, ER and PR respectively.

Formalin-fixed and paraffin-embedded archival tissues of the primary tumors and the lymph node metastases were analyzed by two pathologists. ER, PR and HER2 expression was assessed by fully-automated immunohistochemistry (Ventana medical Systems, USA) and HER2/CEN17 dual chromogenic in situ hybridization (Zytomed Systems, Germany) according to modified ASCO/CAP guidelines (2010 and 2013).

The patients' cohort has been extended for the time period of 2010-2012.

Results: 2006-2010 the detection rate for CTCs was 22% (17/76 patients). In the primary tumors, the expression rate of HER2 was 16% (13/76 patients), 78% for ER (61/76 patients) and 75% for PR (57/76 patients) respectively. Changes in biomarker profiles between primary tumors, metastases and CTCs, as a whole, were observed in 89% of the cases (68/76). The discordance rates between primary tumors and lymph node metastases were 10% for HER2 (p&lt;0.001), 5% for ER (p=p&lt;0.001) and 11% for PR (p&lt;0.001). The intrinsic subtypes between primary tumors and lymph node metastases changed in 16% of all cases (12/76 patients; gain of HER2 in four, activation of HRs in three cases, loss of HER2 in three and loss of HRs in one case becoming triple negative). Of note, both OS and DFS of patients with subtype discordance were reduced to a median of 41 months (mean:39) vs 56 months (mean:51).

CTCs were either triple negative or HER2 positive. Discordance rates for HER2, ER and PR status compared to the primary tumors were 16% (12/76 patients), 83% (63/76 patients)and 72% (55/76 patients), respectively. Discordant rates between lymph node metastases and CTCs were 25% for HER2 (19/76 patients), 82% for ER (62/76 patients) and 72% for PR (55/76 patients).

Enlarged results including the cohort 2010-2012 will be available for SABCS 2017.

Conclusion: Our preliminarily results demonstrate, that changes in molecular profiles are the rule rather than the exception throughout tumor progression in breast cancer. In cases with discordant biomarker profiles, prognosis seems to follow the subtype of lymph node metastasis. Biomarker or subtype shift may be of essential therapeutic significance for individual patients.

Citation Format: Aktas B, Weydandt L, Westerwick D, Mairinger F, Kasimir-Bauer S, Kimmig R, Schmid K, Bankfalvi A. Comparison of HER2, estrogen and progesterone receptor expression profiles of primary tumor, synchronous axillary lymph node metastases and circulating tumor cells in early breast cancer patients [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 PD3-02.

Abstract P1-11-01: Effectiveness, safety and quality of life (QoL) results from the German multicenter AVANTI study of 1st-line bevacizumab (BEV)-containing therapy in &gt;2000 patients (pts) with advanced breast cancer (aBC)

Background: In Europe, BEV is approved with either paclitaxel (PAC) or capecitabine (CAP) as 1st-line therapy for HER2-negative aBC. These regimens are being evaluated in routine oncology practice in the German AVANTI (ML22452) observational study.

Methods: Eligible pts had received no prior chemotherapy (CT) for aBC and had no BEV contraindications. CT schedule, diagnostics and frequency of follow-up are at the physician's discretion. Data are collected for 1 y after starting BEV, with 6-monthly follow-up for 1.5 y thereafter. QoL is assessed using EORTC QLQ-C30. Data cutoff for the 3rd interim analysis was Dec 1, 2016.

Results: Between Oct 2009 and Feb 2015, 2056 eligible pts at &gt;300 centers began treatment with BEV+PAC (n=1658) or BEV+CAP (n=398). Median follow-up was 12.7 (range &lt;0.1–50.9) mo. Median treatment duration was 4.4 (95% CI 4.2–4.6) mo for CT and 6.0 (95% CI 5.8–6.5) mo for BEV. Table 1 summarizes PFS. In the overall population, grade 3/4 AEs were reported in 20% of pts (20% BEV+PAC; 22% BEV+CAP) and led to treatment discontinuation in 5% (5% and 5%, respectively). Mean QLQ-C30 scores were relatively stable over time both overall and in subgroups aged &lt;65 vs ≥65 y, indicating maintained QoL during therapy; no relevant QoL differences between age groups were seen (Table 2). To characterize 'long responders', we identified 459 pts with PFS ≥15 mo (410 BEV+PAC; 49 BEV+CAP). Of these, 33% were aged ≥65 y, 15% had triple-negative aBC (TNBC) and 25% had ≥3 metastatic sites. Median treatment duration was 5.1 mo for CT and 10.8 mo for BEV.

Table 1. PFS by subgroupPtsNo. of events/pts (%)Median PFS (95% CI), moAll1121/2042 (55)14.2 (13.5–15.3)BEV+PAC902/1646 (55)15.2 (14.0–16.2)BEV+CAP219/396 (55)10.9 (10.1–13.4)TNBC187/429 (44)12.6 (10.7–14.3)Non-TNBC677/1486 (46)14.7 (13.6–16.1)&lt;65 y577/1325 (44)15.1 (13.6–16.2)≥65 y344/717 (48)13.5 (12.5–14.9)&lt;3 metastatic sites678/1522 (45)14.4 (13.6–15.8)≥3 metastatic sites254/534 (48)13.5 (11.7–15.5)

Table 2. Mean QoL scores over time, selected scalesScaleTimepointAll pts&lt;65 y≥65 y  nMean scorenMean scorenMean scoreGlobal health statusaBL84046.555747.128345.4 Wk 986744.057044.229743.7 Wk 3352043.335543.716542.4 Wk 5434244.622845.111443.6Physical functioningaBL83668.555570.328164.7 Wk 986360.956864.329554.4 Wk 3351360.335263.316153.8 Wk 5434161.622862.411359.9Social functioningaBL82761.455559.727264.8 Wk 985654.456655.429052.5 Wk 3351455.435156.516353.2 Wk 5433758.122555.811262.8FatiguebBL83548.955548.128050.6 Wk 986059.156756.329364.6 Wk 3351656.135254.516459.7 Wk 5434055.822855.711255.9PainbBL83537.855638.027937.2 Wk 986438.556937.029541.3 Wk 3351746.935345.616449.8 Wk 5434046.922848.111244.5BL=baseline. aHigher score=better QoL/functioning. bHigher score=greater symptom burden.

Conclusions: More mature results from AVANTI show median PFS of 14.2 mo, favorable tolerability and maintained QoL, supporting 1st-line use of BEV for aBC. The subgroup with prolonged disease control (PFS &gt;15 mo) was heterogeneous; further analyses of these pts are ongoing.

Citation Format: Müller V, Jakob A, Aktas B, Grafe A, März W, Fett W, Bruch H-R, Klare P, Hoefflin S, Schneeweiss A. Effectiveness, safety and quality of life (QoL) results from the German multicenter AVANTI study of 1st-line bevacizumab (BEV)-containing therapy in &gt;2000 patients (pts) with advanced breast cancer (aBC) [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 P1-11-01.

Abstract P2-10-03: Genomic markers but not molecular subtypes provide prognostic impact and predict anthracycline efficacy in early triple-negative breast cancer: Results from the prospective WSG PlanB trial

Background: Optimal treatment, particularly use of anthracyclines in aggressive triple-negative breast cancer (TNBC), is still a controversial issue in early BC management. However, TNBC exhibits substantial molecular heterogeneity: for example, the immune phenotype seems to be associated with better outcome. An important clinical issue in early TNBC is to quantify the impact of subtypes as well as individual genes on survival and especially on anthracycline benefit.

Methods: In PlanB, patients with ER and PR&lt;1% (local or central lab), HER2- EBC were treated by TC (6 cycles Docetaxel/Cyclophosphamide) or EC-Doc (4xEpirubicin/Cyclophosphamideà4xDocetaxel) (overall n=2449, HER2-). RNA isolation was successfully performed in n=402/449 patients with available follow-up. Gene (n=119) expression data by Nanostring® platform were entered into univariate and multivariate Cox models for disease-free survival (DFS) to identify genes (and combinations) with potential prognostic and/or predictive impact. Median follow-up was 60 months.

Results: RNA expression results were available in n=394 (203 TC vs. 191 EC-Doc): PAM-50 subtype: basal-like 82%; HER2-enriched 7%; luminal (A or B) 3.5%; normal-like 7.4%. Median age was 54; 78% were node-negative. In patients with “discordant” tumors (HR positive by local or central assessment), 76% were still basal-like, compared to 86% in “concordant” TNBC. Of 27 patients with HER2-enriched subtype, HER2 status was positive by central assessment in only five cases (18%).

Within this TN cohort, 5y DFS was similar in TC (83%) and EC-Doc (79%) arms; positive nodal status and tumor size &gt;2 cm were (unfavorable) clinical-pathological prognostic markers. Prognostic or predictive impacts of molecular subtype, risk of recurrence subgroups, or proliferation indices were not seen.

Twelve genes (incl. CD8, EGFR, GPR160, SPINT2) showed potential multivariate prognostic impact by entering the “forwards stepwise” multivariate Cox model for DFS. The upper half of patients according to the resulting “twelve-gene signature” had well over 90% 5y-DFS, whereas the lowest quartile had under 60% 5-y DFS. Several genes (incl. ERBB2, FOXC1) showed potential for a predictive impact regarding TC vs. EC-Doc by interaction analysis. Further details and perspectives for testing the robustness of these potential impacts will be presented at the meeting.

Conclusions

To our knowledge, these are the first results from a prospective, adjuvant taxane-based trial regarding molecular predictors of anthracycline efficacy and PAM-50-based prognostic factors in early TNBC. ERBB2 expression, but not HER2-enriched subtype, was predictive for A-benefit in HER2-negative BC. Molecular heterogeneity of TNBC beyond basal-like vs. non-basal-like subtype is clinically relevant and should be considered for patient stratification in ongoing trials with combination therapy. The identified prognostic gene signature should be validated in the WSG-ADAPT-TN and other TNBC trials.

Citation Format: Gluz O, Liedtke C, Prat A, Christgen M, Gebauer D, Kates R, Pelz E, Clemens M, Warm M, Aktas B, Kuemmel S, Pare L, Krabisch P, Kreipe HH, Wuerstlein R, Nitz U, Harbeck N. Genomic markers but not molecular subtypes provide prognostic impact and predict anthracycline efficacy in early triple-negative breast cancer: Results from the prospective WSG PlanB trial [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-10-03.

Abstract P2-02-15: Elevated serum RAS p21 is an independent prognostic factor in metastatic breast cancer

Background

An important component of the RAS signalling pathway, the RAS p21 oncogene, is frequently hyperactivated in breast cancer. Its expression in tumor tissue has been linked to poor clinical outcome. This study was designed to evaluate the clinical relevance of RAS p21 levels in peripheral blood in a large cohort of metastatic breast cancer patients.

Methods

251 patients with metastatic breast cancer were enrolled in this prospective, multicentre, non-randomized study conducted on behalf of the DETECT Study Group (Current Controlled Trials ISRCTN59722891). Blood samples were collected before start of first-line or later-line treatment. RAS p21 was determined using a sandwich-type ELISA immunoassay. For the determination of the cutoff, blood samples from age-matched healthy controls were analyzed. A value above 452 pg/ml was regarded as elevated (mean + 2 x SD). In the univariate survival analysis, two other cutoffs were considered as well (50th and 75th percentile of patients, i.e. 229 pg/ml and 320 pg/ml). Circulating tumor cells (CTCs) were detected using the CellSearch system.

Results

29 of 251 (12%) patients had RAS p21 levels above the cut-off level of 452 pg/ml. Clinical-pathological parameters, such as hormone receptor and HER2 status, line of therapy and CTC status, did not correlate with RAS p21 levels.

Patients' characteristics. TotalRAS p21 elevated n (%)p-valueOverall25129 (12%) ER status  0.611Negative7610 (13%) Positive17419 (11%) PR status  0.358Negative10114 (14%) Positive14915 (10%) HER2 status  0.873Negative14318 (13%) Positive769 (12%) Metastatic site  0.482Visceral9813 (13%) Bone352 (6%) Both11814 (12%) Extent of metastatic disease  0.768One site849 (11%) Multiple sites16720 (12%) Therapeutic setting  0.2491st-line988 (8%) 2nd-line6611 (17%) 3rd-line or more8610 (12%) Grading  0.604G151 (20%) G212913 (10%) G310314 (14%) Circulating tumor cells  0.101&lt; 5 CTCs / 7.5 ml12217 (14%) ≥ 5 CTCs / 7.5 ml1219 (7%) 

Elevated RAS p21 was significantly associated with shorter progression-free and overall survival in the univariate analysis (median PFS: 3.9 months [95%-CI: 1.8-6.0] for patients with elevated RAS p21 levels versus 8.5 months [95%-CI: 7.4-9.5] with non-elevated levels [p = 0.01]; median OS: 7.1 months [95%-CI: 0.3-14.2] versus not reached [p = 0.002], respectively). When RAS p21 cutoffs other than 452 pg/ml were considered, elevated RAS p21 was significantly associated with OS (p = 0.019 in case of 229 pg/ml; p = 0.003 in case of 320 pg/ml), but not with PFS. Classical clinical-pathological factors were included into a multivariate Cox regression analysis. In addition, factors previously shown to influence survival in a univariate analysis, such as serum HER2, CAIX and TIMP1, were included as well. In the multivariate analysis, RAS p21, presence of ≥ 5 CTCs per 7.5 ml blood, higher grading and higher line of therapy remained independent predictors of shorter OS.

Conclusions

This is the first study to address the clinical relevance of circulating RAS p21 in a large group of metastatic breast cancer patients. Patients with elevated levels of circulating RAS p21 had significantly worse clinical outcome. Hypothetically, these patients might benefit from therapeutic strategies targeting RAS pathway.

Citation Format: Banys-Paluchowski M, Fehm T, Janni W, Aktas B, Fasching PA, Kasimir-Bauer S, Milde-Langosch K, Pantel K, Rack B, Riethdorf S, Solomayer E-F, Witzel I, Müller V. Elevated serum RAS p21 is an independent prognostic factor in metastatic breast cancer [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 P2-02-15.

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.

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 OT1-02-04: The DETECT V-study – Comparison of dual HER2-targeted therapy with trastuzumab plus pertuzumab in combination with chemo- or endocrine therapy in patients with HER2-positive and hormone-receptor positive metastatic breast cancer

Background: Maintenance of quality of life (QoL) is one of the main aims of treatment of incurable diseases such as metastatic breast cancer (MBC). In patients with HER2-positive MBC, taxan-based chemotherapy in combination with dual HER2 targeted therapy with trastuzumab and pertuzumab has shown promising efficacy results in terms of prolonged survival. However, cytostatic treatment is often accompanied by adverse events of grade 3 or higher, seriously impacting the patients' QoL. In patients with HER2-positive and hormone-receptor positive MBC, the combination of trastuzumab with aromatase inhibitors was shown to be a safe and effective treatment option. The synergistic combination of dual HER2-targeted therapy with trastuzumab and pertuzumab plus endocrine therapy might offer an even better treatment option for these patients. DETECT V is the first prospective randomized phase III clinical trial comparing the safety and efficacy of the dual HER2-targeted therapy in combination with either endocrine therapy or chemotherapy.

Trial design and eligibility criteria: Women with HER2-positive and hormone-receptor positive MBC with first to third line therapy are 1:1 randomized either to a dual HER2-targeted therapy with Pertuzumab and Trastuzumab plus endocrine therapy or to the dual HER2-targeted therapy plus chemotherapy.

Specific aims: The primary objective of this study is to compare the safety and QoL in both arms, as assessed by the occurrence of AEs during the treatment period. We developed a modified adverse event score - including all adverse events grade 3 or higher, except neutropenia, which is included only if rated grade 4, and alopecia, rash, hand-foot-syndrome and peripheral neuropathy which are included if rated grade 2 or higher – in order to better reflect the clinical, physiological and psychological impact of AEs on patients' QoL. Key secondary endpoint, besides the efficacy endpoints progression free survival (PFS) and overall survival, is to compare quality-adjusted survival (QAS), as measured using the quality-adjusted time without symptoms and toxicity (Q-TWiST) method, between both treatment arms. QAS as measured using the Q-TWiST method provides a single metric value that is a composite measure of quantity of survival time and quality of survival as assessed by the patients themselves. Q-TWiST analyses account for possible trade-offs between quantity and quality of life (e.g. prolonged time to progression at the cost of higher toxicity, which adversely affects QoL), and provide an excellent tool to evaluate whether two treatment options differ with regard to the overall perceived value to the patients.

Translational research projects focus on Circulating Tumor Cell(CTC)-enumeration (the presence of CTCs is not obligatory in DETECT V), prognostic role of CTC dynamics, and the assessment of marker expression on CTCs in order to calculate an endocrine responsiveness score which will be evaluated regarding its suitability to predict treatment success.

Contact: For further information on the DETECT V study please contact www.detect-studien.de or studienzentrale.ufk@uniklinik-ulm.de.

Citation Format: Polasik A, Schramm A, Friedl TWP, Rack B, Trapp E, Tzschaschel M, Fasching PA, Taran F-A, Hartkopf A, Schneeweiss A, Müller V, Aktas B, Pantel K, Meier-Stiegen F, Wimberger P, Janni W, Fehm T. The DETECT V-study – Comparison of dual HER2-targeted therapy with trastuzumab plus pertuzumab in combination with chemo- or endocrine therapy in patients with HER2-positive and hormone-receptor positive metastatic 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 OT1-02-04.

Abstract P2-03-09: Comparison of the mutational landscape of breast cancer during pregnancy and non-pregnant controls

Background:Currently, breast cancer during pregnancy (BCP) is not believed to be biologically different from breast cancer unrelated to pregnancy based on limited datasets mainly obtained by immunohistochemistry. However, some groups report that BCP patients have an inferior survival compared to young non-pregnant breast cancer patients. The largest analysis based on the BCP registry by the German Breast Group (GBG) revealed however, no difference between pregnant and non-pregnant breast cancer patients, indicating that treatment rather than biology might be the reason for the inferior survival reported by others.

Methods: The BCP study (GBG 29/BIG 03-02) is a multicentre observational study for breast cancer during pregnancy. In tumour tissue collected within this study from pregnant M0 patients we investigated the following genes: AKT1, ATM, BRAF, CBFB, CCND1, CDH1, CDKN2A, CTCF, EGFR, ERBB2, ESR1, FGFR2, GATA3, KRAS, MAP2K4, MAP3K1, MDM2, MED12, MYC, PIK3CA, PIK3R1, PTEN, RB1, RUNX1, and TP53 by massive parallel sequencing (MPS). This included patients with all molecular subtypes: HR+/-, HER2+/-. Sequencing was done on an IonTorrent Proton using a custom designed Breast Cancer Panel (BCPv2). This panel comprises 236 amplicons split into two primer pools and covers hotspot regions of 138 exons of the 25 genes.

To test the hypothesis that breast cancer diagnosed during pregnancy is biologically not different from breast cancer diagnosed in young non-pregnant women, we compared the molecular profiles obtained, with genetic data from M0 patients not known to be pregnant from TCGA with age &lt;= 45. TCGA data were pre-processed to be compatible to the targeted MPS datasets from pregnant patient.

Results: Material from 141 patients from the BCP study was available from which ultimately 109 fully evaluable MPS datasets could be obtained. In the TCGA data set 114 breast cancer patients &lt;= 45 years could be identified. Pregnant patients with breast cancer were significantly younger, had more often HR- tumours (59.6% vs 30.1%) but had less frequently grade 3 tumours (30.6% vs 48.2%). All other clinical variables showed no significant differences between pregnant and non-pregnant patients. In the BCP data, overall 106 mutations could be found. The most frequent mutations were detected in TP53 (62%) and in PIK3CA (11.1%). In non-pregnant patients the mutation rates were different with 32.5% in TP53 and 21.1% in PIK3CA.

Exact matching by variables age, HR, HER2 and grade yielded 40 patients from both datasets. In these subcohorts, still divergent mutational rates for TP53 and PIK3CA between pregnant and non-pregnant women were noted, however, the differences failed to reach statistical significance.

Conclusions: Overall the mutational landscapes do not seem to be overtly different between pregnant patients and no-pregnant controls, although slight imbalances in mutational rates occurred, which might be partly explained by a selection bias and a small sample size after matching. Further comparisons using other datasets, looking into survival and regarding copy number variation are currently conducted.

This research is been funded by the German Cancer Consortium-DKTK and the BANSS Foundation.

Citation Format: Loibl S, Pfarr N, Weber K, Neunhöffer T, Villegas S, Stenzinger A, Furlanetto J, Aktas B, Budczies J, Marmé F, Kahmann L, Denkert C, Weichert W. Comparison of the mutational landscape of breast cancer during pregnancy and non-pregnant controls [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 P2-03-09.

Abstract OT3-04-02: DETECT III and IV – Individualized CTC-based therapy of metastatic breast cancer

Background: Circulating tumor cells (CTCs) are found in patients with early and metastatic breast cancer (MBC), and both their prognostic and predictive value has been described already. There is growing evidence that CTC phenotype may differ from the primary tumor. However, CTC targeted therapy is not used in clinical routine, and treatment decisions often still are based on the primary tumor's phenotype without considering CTC-characteristics. The aim of the DETECT studies is to investigate and evaluate the role of presence and phenotype of CTC for guiding therapeutic decisions in women with HER2-negative MBC.

Trial design and eligibility criteria: In a joint screening for DETECT III and IV, women with HER2-negative MBC are tested for CTCs and their HER2-phenotype. CTC detection is performed by the FDA-approved CellSearch System® (Janssen Diagnostics, Raritan, USA).

Patients with HER2-positive CTCs are randomized in the multicenter Phase III study DETECT III to a physician's choice chemo- or endocrine therapy with or without additional HER2-targeted treatment with lapatinib.

Women with only HER2-negative CTCs are recruited to the multicenter open-label phase II study DETECT IV. Postmenopausal women with hormone-receptor positive MBC are treated with everolimus and a physician's choice endocrine therapy in DETECT IVa. Patients with hormone-receptor positive MBC and an indication for chemotherapy and patients with triple-negative MBC receive mono-chemotherapy with eribulin in DETECT IVb.

Treatment efficacy will be evaluated based on the early available CTC clearance rate (in DETECT III and DETECT IVa) and progression-free survival (in DETECT IVb) respectively, as the primary endpoint; secondary objectives will be to estimate disease control rate, progression-free (DETECT III and IVa) and overall survival, toxicity and tolerability of treatments with lapatinib, everolimus and eribulin, and quality of life.

Specific aims: Changes in CTC-dynamics during therapy and their HER2-phenotype may influence following therapy decisions. The DETECT studies evaluate the prognostic and predictive role of CTCs as well as the efficacy of CTC based therapy to enable the establishment of a more personalized therapy for patients with MBC that might lead to prolonged progressive free survival and/or improved quality of life. The accompanying translational research programs investigate various markers for molecular characterization of CTCs and prediction of therapy response.

Present accrual and target accrual: More than 1550 patients with HER2-negative MBC have already been screened within the DETECT study program. Thus, it is the worldwide largest study concept with therapy decisions resulting from CTC-testing and CTC-phenotypization.

Contact: For further information on the DETECT study program please contact www.detect-studien.de or studienzentrale.ufk@uniklinik-ulm.de.

Citation Format: Polasik A, Schramm A, Friedl TWP, Rack B, Trapp E, Fasching PA, Taran F-A, Hartkopf A, Schneeweiss A, Müller V, Aktas B, Pantel K, Meier-Stiegen F, Wimberger P, Janni W, Fehm T. DETECT III and IV – Individualized CTC-based therapy of metastatic 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 OT3-04-02.

Abstract P5-16-03: Peripheral sensory neuropathy occurrence and resolution: Results from the neoadjuvant randomized GeparSepto study (GBG 69)

Background: The GeparSepto (NCT01583426) study showed that nab-paclitaxel (nP) increases the pathological complete response (ypT0 ypN0) rate when it replaces paclitaxel (P) as part of a sequential taxane followed by epirubicin/cyclophosphamide (EC) neoadjuvant chemotherapy for pts with early breast cancer (BC) (Untch Lancet Oncol 2016). After a safety analysis showed a higher rate of dose reductions, treatment discontinuations as well as peripheral sensory neuropathy (PSN) with nP 150 mg/m2 w (nP150) compared to P 80mg/m2 w, dose of nP was reduced to 125 mg/m2 w (nP125). The risk-benefit ratio of nP125 was improved over nP150 (von Minckwitz SABCS 2015). We reported follow-up (FU) data on PSN occurrence and resolution.

Methods: Pts with untreated BC received P 80mg/m2 w or nP 150/125mg/m2 w followed by four cycles of E 90 mg/m2 plus C 600 mg/m2 q3w, with trastuzumab 6 mg/kg (loading (LD) dose 8 mg/kg) and pertuzumab 420 mg (LD 840 mg) q3w if HER2+. After the end of the study the protocol was amended in order to collect long-term data on PSN outcome as well as on treatment modalities. PSN will be reported according treatment and dose received on day 1.

Results: Overall 601 pts received P80; 220 pts nP150 and 385 pts nP125 on day 1. PSN grade 2-4 was observed in 18.8% (n=113/601) of pts treated with P80 and in 41.8% (n=92/220) vs 39.2% (n=151/385) with nP150 and nP125 respectively (p=0.547). Grade 3-4 PSN was reported for 2.7% (n=16/601) of pts in the P80 group and 14.5% (n=32/220) vs 8.1% (n=31/385) in the nP150 vs nP125 group respectively (p=0.018). In 31.8% (36/113), 35.9% (33/92) and 27.2% (41/151), PSN was not resolved at the end of the treatment (EOT); PSN grade 3-4 was not resolved in 37.5% (6/16), 56.3% (18/32) and 58.1% (18/31). After a median FU of 110 weeks after EOT, data on PSN status for pts with unresolved PSN grade 2-4 were available from 30, 22 and 32 pts; 26 pts did not provide update information (n=7 died, n=5 data not yet available, n=14 status unknown). For 63.3% (n=19), 40.9% (n=9) and 56.2% (n=18) of pts, PSN grade 2-4 was resolved to grade 1. Time to resolve (TTR) of PSN grade 2-4 was significantly different between nP150 and nP125 (p&lt;0.001); no significant difference was seen between P and nP (p=0.405) [Tab.1]. After a median FU of 103 weeks after EOT, data on PSN status of pts with unresolved PSN grade 3-4 were available for 6, 14 and 14 pts. For 66.6% (n=4), 42.8% (n=6) and 50.0% (n=7) of pts PSN grade 3-4 was resolved to grade 1. TTR of PSN grade 3-4 was not significantly different neither for nP150 vs nP125 (p=0.103) nor for P vs nP (p=0.120) ) [Tab.1].

Conclusions: nP125 is associated with a lower occurrence of PSN compared to nP150 but higher PSN than P80. If PSN occurred nP125 is associated with a more rapid resolution compared to nP150. Nearly 10.7% had no resolution of PSN so far. Further FU and markers for selecting pts at risk are needed.

The trial is supported by Celgene.

Table 1. Median time to resolution (mTTR) of PSN to grade 1comparison groupsmTTR n (weeks); [95% CI]P vs nPPnP150nP125grade 2-47 [6-9]8 [6-10]grade 3-49 [4-15]17 [5-123]nP150 vs nP125 grade 2-4 13 [9-15]6 [4-9]grade 3-4 56 [11-170]17 [10-nr]abbreviations: nP, nab-paclitaxel; P, paclitaxel; nr, not reached

Citation Format: Furlanetto J, von Minckwitz G, Jackisch C, Schneeweiss A, Aktas B, Denkert C, Wiebringhaus H, Kuemmel S, Warm M, Paepke S, Just M, Hanusch C, Hackmann J, Blohmer J-U, Clemens M, Costa SD, Gerber B, Nekljudova V, Untch M, Loibl S. Peripheral sensory neuropathy occurrence and resolution: Results from the neoadjuvant randomized GeparSepto study (GBG 69) [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 P5-16-03.

Abstract P2-09-15: A multi-institutional, prospective study of incorporating the genomic platform breast cancer index as a tool for decision-making regarding extension of adjuvant endocrine therapy

Background: Extending adjuvant endocrine therapy (AET) for hormone responsive breast cancer (HRBC) from 5 to 10 years is beneficial for many in preventing late relapse. Current decision-making regarding extension relies on a decision-making process that weighs non-personalized recurrence risks against risks and benefits of extended AET. The Breast Cancer Index (BCI, BioTheranostics Inc) has been validated to quantify the risk of late recurrence and to predict likelihood of benefit from AET extension based on an individual's tumor genomic profile. The purpose of this study was to conduct a multi-institutional study to prospectively assess the impact of BCI i) on provider's recommendation using the BCI results; 2) the confidence with decision-making; and 3) patient's satisfaction regarding extension of AET.

Methods: Patients with stage I-III HRBC treated at Yale Cancer Center and University of Pittsburgh Medical Center (UPMC), who had completed at least 3.5 years of AET were eligible. BCI was performed on FFPE samples from the original tumor sample (bioTheranostics Inc.). Patients and physicians completed pre- and post-test questionnaires examining preferences for extending AET, patients also completed anxiety and decision-conflict surveys.

Results: 140 patients [mean age 61, 80% postmenopausal, 73% stage I] were included. No extended AET was recommended for 35.3% patients' pre-testing. Reasons physicians did not recommend extended AET were perceived low risk of recurrence (87%), risk of osteoporosis (25%) and side effects (13%). Extended therapy was recommended for 65.7% patients pre-testing. Integration of BCI resulted in a change in physician treatment recommendation in 29% of patients. The recommendation for no extended AET rose to 48% and recommendation for extended AET dropped to 52% (OR=1.76 95% CI 1.08-2.85; p=.003). Of the recommendations that changed (N=41), the majority (73%) was for not extending endocrine therapy. However, 27% of recommendations were to extend endocrine therapy because of high risk or high likelihood of benefit results. More physicians felt strongly confident in their recommendation after the test result (26.4%) than before (9.3%) (OR= 3.5 95% CI 1.77-6.95; p&lt;.0001). Satisfaction of decision increased in 23% of patients (OR=2.72 95% CI 1.66-4.46; p&lt;.0001). Patient reported concerns including the cost, safety and benefit of extended AET decreased from pre- to post-testing (p=.025; p&lt;.0001; p=.0012 respectively)

Conclusions: Overall, incorporation of BCI into clinical practice resulted in significant changes in physician recommendations regarding AET duration, with the majority of recommendations for no extended AET. Physicians reported increased confidence for their recommendation when incorporating the test result. There was also a significant increase in patient satisfaction and decrease in patient reported concerns regarding cost, safety and benefit of extended AET. The BCI is a tool that could be incorporated into decision-making algorithms to enhance physician confidence and patient satisfaction with recommendations for extending AET.

Citation Format: Sanft T, Berkowitz A, Schroeder B, Hatzis C, Schnabel C, Aktas B, Brufsky A, Pusztai L, vanLonden GJ. A multi-institutional, prospective study of incorporating the genomic platform breast cancer index as a tool for decision-making regarding extension of adjuvant endocrine therapy [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 P2-09-15.

Abstract P1-01-09: Comparison of HER2, estrogen and progesterone receptor expression profiles of primary tumor, synchronous axillary lymph node metastases and circulating tumor cells in early breast cancer patients

Background:Targeted systemic therapy in early breast cancer with synchronous lymph node metastasis is currently based on the expression of the hormone receptors (ER/PR ≥1%) and overexpression of HER2 in the primary tumor. However, the expression of these predictive markers on lymph node metastases as well as on circulating tumor cells (CTCs), the precursors of metastatic disease, has not yet been taken into account. The aim of the present study was to compare the HER2/ER/PR expression profiles of primary tumors, synchronous lymph node metastases and circulating tumor cells in early breast cancer patients and relate the results to 5-year overall (OS) and disease-free survival (DFS).

Patients and Methods:76 patients with early breast cancer diagnosed between 2006 and 2010 were enrolled in this study. Blood was obtained at the time of first diagnosis of disease and analyzed for CTCs using the AdnaTest BreastCancer (Qiagen Hannover GmbH) for the expression of EpCAM, MUC-1, HER2, ER and PR respectively.

Formalin-fixed and paraffin-embedded archival tissues of the primary tumors and the lymph node metastases were analyzed by two pathologists. ER, PR and HER2 expression was assessed by fully-automated immunohistochemistry (Ventana medical Systems, Tucson, AZ, USA) and HER2/CEN17 dual chromogenic in situ hybridization (Zytomed Systems, Berlin, Germany) according to modified ASCO/CAP guidelines (2010 and 2013, respectively).

Results: The detection rate for CTCs was 22% (17/76 patients). In the primary tumors, the expression rate of HER2 was 16% (13/76 patients), 78% for ER (61/76 patients) and 75% for PR (57/76 patients) respectively. Changes in biomarker profiles between primary tumors, metastases and CTCs, as a whole, were observed in 89% of the cases (68/76). The discordance rates between primary tumors and lymph node metastases were 10% for HER2 (p&lt;0.001), 5% for ER (p= p&lt;0.001) and 11% for PR (p&lt;0.001). The intrinsic subtypes between primary tumors and lymph node metastases changed in 16% of all cases (12/76 patients; gain of HER2 in four, activation of HRs in three cases, loss of HER2 in three and loss of HRs in one case becoming triple negative). Of note, both OS and DFS of patients with subtype discordance were reduced to a median of 41 months (mean: 39) vs 56 months (mean: 51).

CTCs were either triple negative or HER2 positive. Discordance rates for HER2, ER and PR status compared to the primary tumors were 16% (12/76 patients), 83% (63/76 patients)and 72% (55/76 patients), respectively. Discordant rates between lymph node metastases and CTCs were 25% for HER2 (19/76 patients), 82% for ER (62/76 patients) and 72% for PR (55/76 patients).

Conclusion: Our preliminarily results demonstrate, that changes in molecular profiles are the rule rather than the exception throughout tumour progression in breast cancer. In cases with discordant biomarker profiles, prognosis seems to follow the subtype of lymph node metastasis. Biomarker or subtype shift may be of essential therapeutic significance for individual patients.

Citation Format: Aktas B, Westerwick D, Mairinger F, Kasimir-Bauer S, Kimmig R, Schmid K, Bankfalvi A. Comparison of HER2, estrogen and progesterone receptor expression profiles of primary tumor, synchronous axillary lymph node metastases and circulating tumor cells in early breast cancer patients [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 P1-01-09.

Abstract P6-13-02: Efficacy of first-line bevacizumab (BEV)-containing therapy for poor-prognosis advanced breast cancer (aBC): Subgroup analyses of the German AVANTI observational study

Background: The multicenter AVANTI observational study is evaluating the safety and effectiveness of EU-approved BEV-containing regimens (BEV + paclitaxel [PAC] or BEV + capecitabine [CAP]) as first-line therapy for HER2-negative aBC in German routine oncology practice.

Methods: Eligible patients (pts) had received no prior chemotherapy (CT) for aBC and had no BEV contraindications. CT schedule, diagnostics, and frequency of follow-up visits are at the physician's discretion. Data are collected for 1 year after starting BEV, with 6-monthly follow-up for 1.5 years thereafter. We explored treatment outcomes in pts with triple-negative aBC (TNBC), pts considered at high risk according to a simple prognostic index for OS in BEV-treated pts [Llombart, 2014], and subgroups defined by timing of BEV+CT initiation.

Results: Between Oct 2009 and Feb 2015, 2168 pts treated at 331 centers received BEV+PAC (n=1774) or BEV+CAP (n=394). Of these, 445 (21%) had TNBC and 306 (14%) met the high-risk criteria. Within the hormone receptor-positive (HR+) subgroup, pts receiving endocrine therapy (ET) before BEV+CT were older than pts starting BEV+CT immediately (median age 65 vs 60 years, respectively) and included a smaller proportion with ECOG performance status 0 (39% vs 47%), visceral metastases (70% vs 77%), or prior (neo)adjuvant CT exposure (46% vs 57%). In all subgroups, median BEV treatment duration was longer than median CT duration. At the data cutoff for this interim analysis (Mar 1, 2015), median duration of observation was 10.8 (range &lt;0.1–47.5) months. The table shows treatment exposure and efficacy overall and in selected subgroups.

table 1 All pts (n=2168)TNBC (n=445)aHR+ with immediate BEV+CT (n=1260)a,bHR+ with ET before BEV+CT (n=309)a,bHigh riskc (n=306)bBEV+PAC, n (%)1774 (82)352 (79)b1062 (84)238 (77)229 (75)Treated until PD, n (%)b,d640 (30)180 (40)314 (25)104 (34)125 (41)BEV+CT until PD449 (21)143 (32)210 (17)61 (20)99 (32)Single-agent BEV until PD191 (9)37 (8)104 (8)43 (14)26 (8)Median BEV duration, months (95% CI)5.9 (5.6–6.3)5.1 (4.9–5.6)6.4 (5.9–7.0)5.6 (5.1–6.5)5.1 (4.6–5.6)Median CT duration, months4.6 (4.4–4.9)3.9 (3.5–4.2)4.9 (4.6–5.1)4.6 (4.2–5.1)3.9 (3.3–4.4)No. of PFS events/pts (%)e1238/2154 (57)302/441 (68)667/1255 (53)187/307 (61)210/306 (69)Median PFS, months (95% CI)10.1 (9.7–10.7)7.2 (6.2–8.0)11.5 (10.8–12.3)9.0 (8.3–10.0)6.4 (5.9–7.4)a154 pts could not be classified as TNBC or HR+ because of missing HR status information. bPost hoc analysis. c≥3 of the 5 risk factors (disease-free interval ≤24 months; ECOG performance status ≥2; liver metastases and/or ≥3 metastatic organ sites; TNBC; prior (neo)adjuvant anthracycline and/or taxane). dData available only in pts with documented end of treatment. ePFS data missing in 14 pts.

Conclusions: Interim results from this large observational study indicate that first-line BEV+CT is an effective therapy in all risk subgroups of a general population of pts with HER2-negative aBC treated in routine oncology practice, including pts with a particularly poor prognosis. Results of these exploratory subgroup analyses suggest that BEV+CT could be considered irrespective of HR status.

Citation Format: Mueller V, Jakob A, Aktas B, Pott D, Grafe A, Jungberg P, Maerz W, Fett W, Bruch H-R, Klare P, Boller E, Hoefflin S, Schneeweiss A. Efficacy of first-line bevacizumab (BEV)-containing therapy for poor-prognosis advanced breast cancer (aBC): Subgroup analyses of the German AVANTI observational study [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 P6-13-02.

Abstract P4-21-06: 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

Our recent randomized, multicenter phase III GeparSepto study (Untch M et al. Lancet Oncol 2016) found that substituting nab-paclitaxel for standard solvent-based paclitaxel significantly improved the pathologic complete response (pCR) rate in patients receiving a sequential regimen of taxane, epirubicin and cyclophosphamide as neoadjuvant treatment for high-risk primary breast cancer. Patients with HER2-positive tumors (32.8%; n=396) also received a combination of pertuzumab and trastuzumab: the present analysis focuses on efficacy and safety data from these HER2+ patients treated with the dual-blockade.

Methods

Patients with histologically confirmed early breast cancer (n = 1206) received either weekly paclitaxel 80mg/m2 or weekly nab-paclitaxel 150/125mg/m2, according to randomization), followed by four cycles of epirubicin 90 mg/m2 plus cyclophosphamide 600 mg/m2 q3w, with concurrent trastuzumab 6 mg/kg (loading (LD) dose 8 mg/kg) and pertuzumab 420 mg (LD 840 mg) q3w for those with HER2-positive tumors. The primary endpoint was pathologic complete response (pCR), defined as ypT0 ypN0.

Results

The GeparSEPTO trial included 396/1206 (32.8%) HER2+ primary breast cancer patients. 27.0% in the HER2-positive and 34.1% in the HER2-negative group had HR-negative disease. Baseline characteristics were otherwise comparable between HER2+ and HER2- patients. Higher rates of pCR were seen in HER2+, compared to HER2- tumors (57.8% vs 22.0%). The highest overall pCR rate was observed in the HER2+/HR- cohort with 71.0%; 66.7% with Pac and 74.6% with nab-Pac. In HER2+/HR+ pCR rate was 52.9% ; 49.4% with Pac and 56.4% with nab-Pac. Using the definition ypT0/is ypN0 for pCR; pCR rates were generally higher especially in the HER2+ cohort (66.2% (ypT0/is ypN0) vs 57.8% (ypT0 ypN0)) compared to 25.2% (ypT0/is ypN0) vs 22% (ypT0 ypN0)) in patients with HER2-negative tumors. The HER2+ patients experienced a significantly higher incidence of grade 3-4 adverse events 85.4% vs 78.0% in the HER2-cohort, p=0.003); grade 3-4 hematologic AEs 74.0% (HER2+) vs 69.5% (HER2-); p=0.120 with grade 3-4 anaemia 2.5% vs 0.9%; p=0.034); any grade thrombopenia 28.5% vs 21.8%; p=0.012) and febrile neutropenia 6.3 vs 3.3%; p=0.023. Any grade 3-4 non-haematological toxicities occurred in 38.4% vs 30.1%; p=0.005), with grade 3-4 diarrhea occurring in 7.6% vs 0.9%; p&lt;0.001 of the patients. This had no impact on compliance. LVEF decreases from baseline were uncommon (7.6%) with 2.0% (HER2+) versus 0.4% (HER2-) of patients showing decreases to &lt;50% along with a ≥10% decrease from baseline.

Conclusion

This is the largest cohort of patients with HER2-positive early breast cancer receiving a dual HER2-targeted neoadjuvant therapy of pertuzumab and trastuzumab, together with nab-paclitaxel or paclitaxel followed by epirubicin and cyclophosphamide. HER2+ patients experienced more noteworthy toxicity. The pCR rate were higher in the HER2+ cohort receiving the dual blockade and was highest in patients with in HER+/HR- particularly if nab-paclitaxel was substituted for paclitaxel.

The trial is financially supported by Celgene and Roche.

Citation Format: Loibl S, Jackisch J, Schneeweiss A, Schmatloch S, Aktas B, Denkert C, Schem C, Wiebringhaus H, Kuemmel S, Luebbe K, Warm M, Just M, Hanusch C, Hackmann J, Blohmer J-U, Clemens M, Engels K, Nekljudova V, von Minckwitz G, Untch M. Dual HER2-blockade with pertuzumab and trastuzumab in HER2-positive early breast cancer: A subanalysis of data from the randomized phase III GeparSepto 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 P4-21-06.