Influence of HER2 expression on prognosis in metastatic triple-negative breast cancer-results from an international, multicenter analysis coordinated by the AGMT Study Group

BACKGROUND

Triple-negative breast cancer (TNBC) is associated with poor prognosis, and new treatment options are urgently needed. About 34%-39% of primary TNBCs show a low expression of human epidermal growth factor receptor 2 (HER2-low), which is a target for new anti-HER2 drugs. However, little is known about the frequency and the prognostic value of HER2-low in metastatic TNBC.

PATIENTS AND METHODS

We retrospectively included patients with TNBC from five European countries for this international, multicenter analysis. Triple-negativity had to be shown in a metastatic site or in the primary breast tumor diagnosed simultaneously or within 3 years before metastatic disease. HER2-low was defined as immunohistochemically (IHC) 1+ or 2+ without ERBB2 gene amplification. Survival probabilities were calculated by the Kaplan-Meier method, and multivariable hazard ratios (HRs) were estimated by Cox regression models.

RESULTS

In total, 691 patients, diagnosed between January 2006 and February 2021, were assessable. The incidence of HER2-low was 32.0% [95% confidence interval (CI) 28.5% to 35.5%], with similar proportions in metastases (n = 265; 29.8%) and primary tumors (n = 425; 33.4%; P = 0.324). The median overall survival (OS) in HER2-low and HER2-0 TNBC was 18.6 and 16.1 months, respectively (HR 1.00; 95% CI 0.83-1.19; P = 0.969). Similarly, in multivariable analysis, HER2-low had no significant impact on OS (HR 0.95; 95% CI 0.79-1.13; P = 0.545). No difference in prognosis was observed between HER2 IHC 0/1+ and IHC 2+ tumors (HR 0.89; 95% CI 0.69-1.17; P = 0.414).

CONCLUSIONS

In this large international dataset of metastatic TNBC, the frequency of HER2-low was 32.0%. Neither in univariable nor in multivariable analysis HER2-low showed any influence on OS.

Austrian treatment algorithms in HER2-positive metastatic breast cancer: a 2022 update

In the past 12 months a plethora of relevant novel data for the treatment of metastatic HER2 positive breast cancer were published. To bring this new evidence into a clinical perspective, a group of Austrian breast cancer specialists updated their previously published treatment algorithm for those patients. For this consensus paper a total of eight scenarios were developed in which treatment strategies appropriate for specific patient profiles were evaluated. Consensus was established by detailed discussions of each scenario and by reaching full consensus.

Abstract P1-21-08: Brain metastases (BM) from breast cancer: Real-word data from the Austrian AGMT_MBC-registry

Background: BM are generally associated with poor prognosis and with neurological impairments making BM a major limitation of life expectancy and quality of life in MBC. Real-world data are needed in order to quantify and better characterize this special clinical situation. Here, we present data from the MBC registry of the Austrian Study Group for Medical Tumor Therapy (AGMT-MBC-Registry). Methods: The AGMT-MBC-Registry is an ongoing multicenter registry for MBC patients in Austria. Patients with available hormone receptor and HER2 status and sufficient outcome data were included in this analysis. Unadjusted, univariate overall survival (OS) probabilities were calculated by the Kaplan-Meier method and compared by the log-rank test; multivariable adjusted hazard ratios (HR) were estimated by Cox regression models. HR were estimated with diagnosis of BM as time-dependent variable. Logistic regression was performed to investigate the probability of developing BM. Multivariable analyses included the following parameters: breast cancer subtype (luminal-like vs. HER2+ vs. TNBC), age at diagnosis of metastatic disease (continuous, in Cox regression as interaction with menopausal status), DFS (de novo metastatic or ≥ 24 months vs. < 24 months), visceral disease (yes vs. no) and number of metastatic sites (1 vs 2-3 vs. ≥4) at diagnosis of metastatic disease. Results: As of 15/04/2021, 2024 patients were included in the registry. Out of 1691 evaluable patients, 306 (18.1%) had documented BM. The incidence at diagnosis of metastatic disease and the overall incidence during the course of disease was significantly higher in HER2+ (9.5% [13/137] and 36.5% [50/137]) and triple-negative tumors (11.9% [38/318] and 27.7% [88/318]) compared to luminal-like tumors (3.3% [41/1236] and 13.6% [168/1236]) (both P<0.001). Besides subtype, ≥4 metastatic sites at diagnosis of metastatic disease and age were statistically significant associated with BM in logistic regression analysis.Median time to BM calculated from the date of diagnosis of metastatic disease was 11.3 months (95%CI 9.3-13.3) in the total population with BM, 12.7 months (95%CI 7.3-16.0) in HER2+, 5.2 months (95%CI 1.8-10.3) in triple-negative and 15.4 months (95%CI 8.4-19.5) in luminal disease, respectively. Interestingly, 13.7% of patients (42/306) had BM as first metastatic site without extracranial disease. The median number of systemic therapy-lines before and after diagnosis of BM was 1 (range 0-8) and 1 (range 0-10), respectively. Most of the patients with BM (80.1%) received radiotherapy; 12.7% focal radiotherapy, 69.8% whole brain irradiation and 9.0% both types of radiotherapy (8.5% unknown). After a median follow-up of 72.3 months (95%-CI 68.6-80.0), patients with BM had a significantly shorter median OS (7.5 months) compared to patients without BM (38.4 months) both in univariate (HR 3.58; 95%CI 3.11-4.11; P<.001) and multivariable analysis (HR 3.70; 95%CI 3.18-4.32; P<.001). OS in patients with BM differed significantly between the three breast cancer subtypes with a median OS of 36.3 months (95%CI 30.5-47.9), 33.5 months (95%CI 22.9-45.5) and 13.2 months (95%CI 11.1-18.4) in luminal, HER2+ and TNBC, respectively (overall log-rank P<0.001). Similarly, the time from diagnosis of BM and death was significantly shorter in TNBC (4.1 months; 95%CI 3.4-6.3) compared to luminal (9.7 months; 95%CI 6.8-13.7) and HER2+ breast cancer (10.7 months; 95%CI 9.1-26.2) (overall log-rank P<0.001). Conclusion: Almost 20% of patients with MBC develop BM during their course of disease, with a higher incidence in HER2+ and triple-negative disease. Besides effective prevention strategies improved systemic and local therapies are needed to minimize morbidity and improve outcome in these patients.

Citation Format: Simon Peter Gampenrieder, Gabriel Rinnerthaler, Christoph Tinchon, Andreas Petzer, Marij Balic, Sonja Heibl, August F Zabernigg, Daniel Egle, Margit Sandholzer, Florian Roitner, Johannes Andel, Petra Pichler, Christopher Hager, Michael Knauer, Michael Hubalek, Christian F Singer, Richard Greil. Brain metastases (BM) from breast cancer: Real-word data from the Austrian AGMT_MBC-registry [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-21-08.

Updated Austrian treatment algorithm in HER2+ metastatic breast cancer

A group of Austrian breast cancer specialists met in December 2020 to establish a comprehensive clinical benefit-risk profile of available HER2-targeted therapies based on recent data and to develop an updated treatment algorithm by consensus over several months in 2021. A total of four scenarios were developed in which treatment strategies appropriate for specific patient profiles were evaluated. Consensus was established by detailed discussions of each scenario and by reaching full consensus.

Landscape of HER2-low metastatic breast cancer (MBC): results from the Austrian AGMT_MBC-Registry

Background

About 50% of all primary breast cancers show a low-level expression of HER2 (HER2-low), defined as immunohistochemically 1+ or 2+ and lack of HER2 gene amplification measured by in situ hybridization. This low HER2 expression is a promising new target for antibody–drug conjugates (ADCs) currently under investigation. Until now, little is known about the frequency and the prognostic value of low HER2-expression in metastatic breast cancer (MBC).

Patients and methods

The MBC-Registry of the Austrian Study Group of Medical Tumor Therapy (AGMT) is a multicenter nationwide ongoing registry for MBC patients in Austria. Unadjusted, univariate survival probabilities of progression-free survival (PFS) and overall survival (OS) were calculated by the Kaplan–Meier method and compared by the log-rank test. Multivariable adjusted hazard ratios were estimated by Cox regression models. In this analysis, only patients with known HER2 status and available survival data were included.

Results

As of 11/15/2020, 1,973 patients were included in the AGMT-MBC-Registry. Out of 1,729 evaluable patients, 351 (20.3%) were HER2-positive, 608 (35.2%) were HER2-low and 770 (44.5%) were completely HER2-negative (HER2-0). Low HER2-expression was markedly more frequent in the hormone-receptor(HR)+ subgroup compared to the triple-negative subgroup (40% vs. 23%). In multivariable analysis, low HER2 expression did not significantly influence OS neither in the HR+ (HR 0.89; 95% CI 0.74–1.05; P = 0.171) nor in the triple-negative subgroup (HR 0.92; 95% CI 0.68–1.25; P = 0.585), when compared to completely HER2-negative disease. Similar results were observed when HER2 IHC 2+ patients were compared to IHC 1+ or 0 patients.

Conclusion

Low-HER2 expression did not have any impact on prognosis of metastatic breast cancer in this real-world population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-021-01492-x.

Capecitabine in combination with bendamustine in pretreated women with HER2-negative metastatic breast cancer: results of a phase II trial (AGMT MBC-6)

Background:

Bendamustine, a medication approved for the treatment of indolent non-Hodgkin lymphoma, has already shown anticancer activity in metastatic breast cancer (MBC). Here, we present the results of a phase II trial of bendamustine in combination with capecitabine in pre-treated patients with MBC.

Patients and methods:

AGMT MBC-6 is a multicentre, open-label, single-arm phase II study in HER2-negative MBC. All patients were pre-treated with anthracyclines and/or taxans and had measurable disease. Patients received per os 1000 mg/m² capecitabine twice daily on days 1 to 14 in combination with 80 mg/m² bendamustine intravenously on days 1 and 8 of a 3-week cycle for a maximum of eight cycles, followed by a capecitabine maintenance therapy. The primary endpoint was overall response rate (ORR).

Results:

From September 2013 to May 2015, 40 patients were recruited in eight Austrian centres. The median age was 60 years (range 29–77). Twenty-five per cent of patients had triple-negative breast cancer (TNBC) and 93% showed visceral involvement. With 17 partial and one complete remission, ORR was 46%. Median progression-free survival (PFS) was 7.5 months [95% confidence interval (CI) 6.1–10.7]. The most common non-haematological adverse events (AEs) of grade 3 were hand-foot syndrome (13%), fatigue (10%), nausea (8%), and dyspnoea (8%). One grade 4 non-haematological AE (hepatic failure) and three grade 4 haematological AEs (neutropenia) were observed. One patient died of restrictive cardiomyopathy, in which a relationship to capecitabine cannot be excluded, but seems unlikely.

Conclusion:

The combination of capecitabine and bendamustine shows promising efficacy and moderate toxicity. Further evaluation of this drug combination is warranted.

The clinical trial AGMT MBC-6 was registered at ClinicalTrials.gov, (https://clinicaltrials.gov/; identifier: NCT01891227).

Abstract PS1-41: Does complete surgical removal of metastases in oligometastatic breast cancer improve survival? A matched-pair analysis of the AGMT_MBC-registry

Background: Metastatic breast cancer (MBC) is generally thought to be a systemic and incurable disease requiring systemic therapy. However, surgical resection of oligometastatic disease might be of benefit similar to other malignant diseases. Here, we present the results from a matched analysis of patients undergoing radical surgery of metastases.

Methods: The MBC registry of the Austrian Study Group for Medical Tumor Therapy (AGMT) is an ongoing multicenter registry for MBC patients in Austria. Patients undergoing surgical removal of all metastatic sites (+/- primary tumor and lymph node dissection) were identified and matched 1:1 according to disease-free survival (de novo metastatic vs. < 24 vs. ≥ 24 months), location of metastases, subtype (HR+/HER2- vs. HR+/HER2+ vs. HR-/HER2+ vs. triple-negative) and age (≥ 60 vs. < 60). OS was defined as time from diagnosis of metastatic disease until death. Only patients with available matching parameters and sufficient outcome data were included in this analysis.

Results: As of 24/06/2020, 1904 patients were enrolled into the AGMT_MBC-Registry; 24 of them received surgery of metastases and 23 had a complete match with patients without surgery. In the surgery group, five patients (21.7%) received immediate postperative chemotherapy and 80.0% received further chemotherapy after surgery. Out of patients with HR+ disease (n=15), 86.7% received endocrine therapy prior and/or after surgery. We found a numerically but not statistically significant longer overall OS in patients undergoing surgery (47.4 vs. 29.6 months, HR 0.61; 95%CI 0.30-1.24; P=0.171). Two, five and ten year survival estimates were 82.6% (95%CI 68.5-99.6), 31.3% (95%CI 15.7-62.5) and 31.3% (95%CI 15.7-62.5) in the surgery group and 59.1% (95%CI 41.7-83.7), 24.8% (95%CI 11.7-52.6) and 13.2% (95%CI 4.0-43.1) in the non-surgery group, respectively. The largest benefit for surgery was found in the luminal and HER2-positive subtypes, while no benefit was observed in the triple-negative subgroup.

Conclusion: Radical surgery of all metastases seems to improve survival, especially in luminal and HER2-positive subtypes, however, the analysis did not reach statistical significance, most probably due to the low patient number. Furthermore, because of the retrospective and non-randomized design, a systematic bias cannot be totally excluded.

Citation Format: Simon Peter Gampenrieder, Gabriel Rinnerthaler, Christoph Tinchon, Andreas Leo Petzer, Christoph Suppan, MD, Sonja Heibl, Daniela Voskova, August F Zabernigg, MD, Daniel Egle, MD, Margit Sandholzer, MD, Christian F Singer, Florian Roitner, Johannes Andel, Michael Hubalek, Michael Knauer, Richard Greil. Does complete surgical removal of metastases in oligometastatic breast cancer improve survival? A matched-pair analysis of the AGMT_MBC-registry [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS1-41.

Overcoming negative predictions of microRNA expressions to gemcitabine response with FOLFIRINOX in advanced pancreatic cancer patients

FOLFIRINOX is superior to gemcitabine in patients with pancreatic cancer, but this regimen is associated with toxicity and biomarkers for response are warranted. MicroRNAs can mediate drug resistance and could provide predictive information. Altered expressions of several microRNAs including miR-21-5p, miR-10b-5p and miR-34a-5p have been previously linked to a worse response to gemcitabine. We investigated the influence of expression levels in tumor tissue of those three microRNAs on outcome to FOLFIRINOX. Twenty-nine patients with sufficient formalin-fixed paraffin-embedded tumor tissue were identified. There was no significant association between high and low expression groups for these three microRNA. We conclude that polychemotherapy combination can overcome intrinsic negative prognostic factors.

Treatment Landscape for Patients with HER2-Positive Metastatic Breast Cancer: A Review on Emerging Treatment Options

The prognosis of HER2-positive metastatic breast cancer (MBC) has radically changed in recent years and continues to improve due to the broad application of effective therapies like monoclonal antibodies and small molecules targeting HER2. Persistent dependency of tumor cells on the oncogene HER2, on one hand, as well as low expression levels in healthy tissue, on the other hand, make this protein an ideal target for anti-cancer therapy. New HER2 targeting strategies including targeted delivery of cytotoxic drugs via HER2 receptor have been developed. Recently, the US Food and Drug Administration (FDA) approved three new drugs for the treatment of HER2-positive MBC: the antibody–drug conjugate trastuzumab deruxtecan and the two tyrosine kinase inhibitors neratinib and tucatinib. Here, we summarize recent publications and developments of novel anti-HER2 therapies like monoclonal antibodies with improved properties compared to trastuzumab and bispecific antibodies, which bind two different HER-epitopes or bring T cells closer to tumor cells. Furthermore, novel antibody-drug conjugates and small molecules against HER2 are discussed. These developments coupled with new combination strategies (eg, with CDK4/6 inhibitors or immunotherapy) will change the treatment landscape for patients with HER2-positive MBC very soon and will hopefully further improve clinical outcomes.

Abstract P3-08-29: Landscape of HER2-low metastatic breast cancer (MBC): Results from the AGMT-MBC-Registry

Background: About 50% of all primary breast cancers show a low-level expression of HER2 (HER2-low), defined as immunohistochemically 1+ or 2+ and lack of HER2 gene amplification measured by in-situ hybridization. This low HER2 expression is a promising new target for antibody-drug conjugates (ADCs) currently under development. Until now, little is known about the frequency and the prognostic value of low HER2-expression in metastatic breast cancer (MBC). Patients and methods: The MBC-Registry of the Austrian Study Group of Medical Tumor Therapy (AGMT) is a multicenter nationwide ongoing retrospective and prospective registry for MBC patients in Austria. Unadjusted, univariate survival probabilities of PFS and OS were calculated by the Kaplan-Meier method and compared by the log-rank test, multivariate hazard ratios (HR) were estimated by Cox regression models. In this analysis patients with known HER2 status and available survival data were included. Results: As of 31/01/2019, 1,253 patients were included in the AGMT-MBC-Registry. Out of 1,079 evaluable patients, 262 (24.3%) were HER2-positive, 372 (34.5%) were HER2-low and 445 (41.2%) were completely HER2-negative (HER2-0). The distribution of hormone receptor (HR) expression is shown in Table 1. Median OS and median first-line PFS for these three subgroups in dependency of HR expression is presented in Table 2. Neither in univariate (p=0.821) nor in multivariate analysis including HR status, disease-free survival (DFS), age and visceral disease (p=0.590, HR 1.06), low HER2 expression had a significant impact on prognosis compared to completely HER2-negative disease. Overall 13/372 (3.5%) of the HER2-low and 11/445 (2.5%) of the HER2-0 patients received anti-HER2 treatment. In the HER2+ cohort 200/262 (76.3%) were treated with trastuzumab, 106 (40.5%) with pertuzumab and 49 (18.7%) with T-DM1. In the HR+ subgroup, 11/162 (6.8%), 78/302 (25.8%) and 89/323 (27.6%) patients were treated with a CDK4/6 inhibitor in the HER2+, HER2-low and HER2-0 subgroup, respectively. Conclusion: Low-HER2 expression did not have any impact on prognosis or choice of treatment in metastatic breast cancer in this real-world population.

Table 1HER2-positive (IHC 3+ or ISH+)HER2-low (IHC1+ or 2+ and ISH-)completely HER2-negative (IHC 0)All (n=1,079)262 (24.3%)372 (34.5%)445 (41.2%)HR+ (n=787)162 (20.6%)302 (38.4%)323 (41.0%)HR- (n=292)100 (34.2%)70 (24.0%)122 (41.8%)

Table 2HER2+ months (95%CI)HER2-low months (95%CI)HER2-0 months (95%CI)Log-rankPMedian OSAll (n=1,079)42.7 (32.5-52.9)32.2 (27.3-37.1)30.8 (26.0-35.7)0.007HR+ (n=787)49.6 (40.1-59.1)35.8 (31.4-40.2)40.5 (35.4-45.5)0.120HR- (n=292)26.4 (19.9-33.0)16.8 (12.9-20.7)14.3 (10.0-18.6)< 0.001Median 1st-line PFS All (n=913)*12.4 (10.1-14.8)11.0 (9.3-12.7)11.3 (9.6-12.9)0.123HR+ (n=684)*14.6 (10.8-18.4)12.4 (10.3-14.5)14.7 (12.1-17.4)0.348HR- (n=229)*11.0 (8.2-13.9)5.6 (3.9-7.2)6.0 (4.4-7.5)< 0.001* only patients with at least one line of therapy for metastatic disease and sufficiently documented medical records allowing calculation of PFS were included.

Citation Format: Simon Peter Gampenrieder, Gabriel Rinnerthaler, Andreas Petzer, Christoph Tinchon, David Fuchs, Marija Balic, Sonja Heibl, Holger Rumpold, Daniel Egle, August Felix Zabernigg, Christian Fridolin Singer, Johannes Andel, Michael Hubalek, Michael Knauer, Richard Greil. Landscape of HER2-low metastatic breast cancer (MBC): Results from the AGMT-MBC-Registry [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-08-29.

"I was seen by a radiologist, but unfortunately I can't remember the name and I still have questions. What should I do?" Radiologists should give thoughts to improve service professionalism and patient esteem

Background

The aim of the study is to investigate how well patients remember the radiologist’s name after a radiological examination, and whether giving the patient a business card improves the patient’s perception of the radiologist’s professionalism and esteem.

Methods

In this prospective and randomized two-centre study, a total of 141 patients with BI-RADS 1 and 2 scores were included. After screening examination comprising mammography and ultrasound by a radiologist, 71 patients received a business card (group 1), while 70 received no business card (group 2). Following the examination, patients were questioned about their experiences.

Results

The patients in group 1 could remember the name of the radiologist in 85% of cases. The patients in group 2, in contrast, could only remember the name in 7% of cases (p < 0.001). 90% of the patients in group 1 believed it was very important that they are able to contact the radiologist at a later time, whereas only 76% of patients in group 2 felt that this was a very important service (p < 0.025). A total of 87% of the patients in group 1 indicated that they would contact the radiologist if they had any questions whereas 73% of the patients in group 2 would like to contact the radiologist but were not able to do so, because they could not remember the name (p < 0.001).

All questions were analysed with a Cochran-Mantel-Haenszel (CMH) test that took study centre as stratification into account. In some cases, two categories were collapsed to avoid zero cell counts.

Conclusions

Using business cards significantly increased the recall of the radiologist’s name and could be an important tool in improving the relationships between patients and radiologists and enhancing service professionalism.

Trial registration

We have a general approval from our ethics committee. The patients have given their consent to this study.

Transcatheter aortic valve implantation in a patient with suspected hereditary von Willebrand disease and severe gastrointestinal bleeding - a case report

INTRODUCTION

von Willebrand disease is the most common hereditary coagulopathy and is characterised by a deficiency in the quantity or quality of the von Willebrand factor. Heyde Syndrome, in contrast, is an acquired form of von Willebrand syndrome (AVWS) due to calcific aortic valve stenosis, characterised by gastrointestinal bleeding from angiodysplasia.

CASE PRESENTATION

A 73-year-old patient presented with severe gastrointestinal bleeding and stated that she suffered from hereditary von Willebrand disease. Upon echocardiography, a severe aortic valve stenosis was found, and hence the suspicion of additional AVWS was raised. Since endoscopic interventions and conservative therapeutic approaches did not result in a cessation of the bleeding, transcatheter aortic valve implantation (TAVI) was performed to stop the additional shear stress on von Willebrand factor. This resulted in cessation of the bleeding.

CONCLUSION

Retrospectively, this life-threatening gastrointestinal bleeding was a result of severe Heyde Syndrome, which could be alleviated by TAVI. Whether the patient had suffered from inherited von Willebrand disease in the past, remains uncertain. AVWS should be considered in patients with suspected inherited von Willebrand disease and concomitant severe aortic valve stenosis, since it constitutes a treatable cause of a potentially severe bleeding disorder.

Baseline Absolute Lymphocyte Count and ECOG Performance Score Are Associated with Survival in Advanced Non-Small Cell Lung Cancer Undergoing PD-1/PD-L1 Blockade

Immune-checkpoint blockade in front-line or second-line treatment improves survival in advanced non-small cell lung cancer (aNSCLC) when compared with chemotherapy alone. However, easily applicable predictive parameters are necessary to guide immune-checkpoint inhibition in clinical practice. In this retrospective bi-centric analysis, we investigated the impact of baseline patient and tumor characteristics on clinical outcome in aNSCLC patients treated with programmed cell death protein 1(PD-1)/programmed cell death ligand 1 (PD-L1) inhibitors. Between May 2015 and January 2018, 142 unselected consecutive NSCLC patients received PD-1/PD-L1 inhibitors during the course of disease. In multivariate analysis, we identified the Eastern Cooperative Oncology Group (ECOG) performance status (ECOG > 1 versus ECOG ≤ 1, HR: 3.23, 95%CI: 1.58-6.60, P = 0.001), baseline absolute lymphocyte count (ALC; high: >0.93 × 109/L versus low: ≤ 0.93 × 109/L, HR: 0.38, 95%CI: 0.23-0.62, P < 0.001), prior or concomitant anti-vascular endothelial growth factor (VEGF) targeting therapy (yes versus no, HR: 2.18, 95%CI: 1.15-4.14, P = 0.017) and TNM stage (IV versus III, HR: 4.18, 95%CI: 1.01-17.36, P = 0.049) as the most relevant parameters for survival. Neither antibiotic exposure (antibiotic-positive versus antibiotic-negative, HR: 0.90, 95%CI: 0.56-1.45, P = 0.675), nor PD-L1 expression on tumor cells (≥1% versus <1%, HR: 0.68, 95%CI: 0.41-1.13, P = 0.140) was associated with survival. Baseline ECOG performance status and ALC were associated with survival in aNSCLC patients treated with PD-1/PD-L1 inhibitors and assessment of these parameters could be suitable in clinical practice.

HER2 Directed Antibody-Drug-Conjugates beyond T-DM1 in Breast Cancer

Since the discovery of the human epidermal growth factor receptor 2 (HER2) as an oncogenic driver in a subset of breast cancers and the development of HER2 directed therapies, the prognosis of HER2 amplified breast cancers has improved meaningfully. Next to monoclonal anti-HER2 antibodies and tyrosine kinase inhibitors, the antibody-drug conjugate T-DM1 is a pillar of targeted treatment of advanced HER2-positive breast cancers. Currently, several HER2 directed antibody-drug conjugates are under clinical investigation for HER2 amplified but also HER2 expressing but not amplified breast tumors. In this article, we review the current preclinical and clinical evidence of the investigational drugs A166, ALT-P7, ARX788, DHES0815A, DS-8201a, RC48, SYD985, MEDI4276 and XMT-1522.

Abstract P3-10-07: A 3-gene DNA methylation signature fails to predict response to bevacizumab in metastatic breast cancer patients treated within the TANIA phase III trial

Background: Biomarkers predicting response to bevacizumab containing therapy in metastatic breast cancer (MBC) are of urgent need. In a retrospective single-institution analysis we have previously shown that a 3-gene methylation signature (MLH1,POLKand TMBIM6) could discriminate between responders and non-responders to a bevacizumab-based therapy in two independent cohorts of patients with MBC with an AUC of 0.94 and 0.86, respectively (Gampenrieder SP et al. Theranostics. 2018. 8(8):2278-2288). Here, we present the validation of these findings within the prospective phase III trial TANIA (Vrdoljak E et al. Ann Oncol. 2016. 27(11):2046-52) randomizing 494 patients with HER2-negative MBC to chemotherapy plus bevacizumab or chemotherapy alone for two consecutive treatment lines (second- and third-line). All patients had already received bevacizumab-containing therapy in the first-line setting.

Patients and methods: DNA isolated from archival FFPE tumor samples was available from 200 patients consenting to optional translational research within the TANIA trial. Out of these, 176 samples were collected prior to first-line bevacizumab therapy and were analyzed retrospectively. Sufficient DNA for methylation analysis was available from 124 patients: 64 treated with chemotherapy plus bevacizumab and 60 treated with chemotherapy alone. All samples were isolated from the primary tumor. Quantitative methylation analysis was performed by pyrosequencing on the PyroMark Q24 Advanced System (Qiagen). PFS and OS analyses were performed in both study arms comparing “predicted responders” (PRED_R) versus “predicted non-responders” (PRED_NR) based either on median dichotomization or according to the cutoffs for individual CpG and the combined 3-CpG methylation logistic regression model.

Results:Out of the 124 evaluable patients, 32 (25.8%) were classified as PRED_R and 92 as RED_NR by the 3-gene methylation signature. PRED_R did not have a significantly different second-line PFS (HR 0.95, 95%CI 0.57-1.57; P = 0.84) or OS (HR 0.91, 95%CI 0.51-1.60; P = 0.73) when treated in the bevacizumab-containing study arm compared to PRED_NR. In addition, PRED_R did not show a longer PFS when treated with bevacizumab compared to PRED_R treated with chemotherapy alone (HR 0.95, 95%CI 0.59-1.54; P = 0.83). Furthermore, there was no difference in third-line PFS and the combination of second- and third-line PFS between PRED_R and PRED-NR in the bevacizumab arm. In the control arm, PRED_NR showed a statistically significant shorter PFS compared to PRED_R (HR 0.50, 95%CI 0.22-0.77; P = 0.006), but not OS (HR 0.95, 95%CI 0.51-1.77; P = 0.86).

Conclusion: Our 3-gene methylation signature was not confirmed as predictive biomarker for bevacizumab efficacy in metastatic breast cancer.

(This research project was partially supported by ROCHE Austria GmbH)

Citation Format: Gampenrieder SP, Angela R, Rinnerthaler G, Hackl H, Steiner M, Pulverer W, Weinhaeusel A, Klinglmayr E, Karl T, Ilic S, Hufnagl C, Hauser-Kronberger C, Egle A, Greil R. A 3-gene DNA methylation signature fails to predict response to bevacizumab in metastatic breast cancer patients treated within the TANIA phase III 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 P3-10-07.

Abstract OT3-07-01: Ixazomib in combination with carboplatin in pretreated women with advanced triple negative breast cancer, an ongoing phase I/II trial (AGMT MBC-10 trial)

Background:Triple-negative breast cancer (TNBC) comprises a heterogeneous group of diseases which are generally associated with poor prognosis. Recently, the PARP inhibitor olaparib was approved as first targeted treatment beyond antiVEGF therapy for the BRCA1/2 mutated subgroup of TNBC. However, cytotoxic agents still remain the mainstay of treatment for this breast cancer subtype. Ixazomib is a selective and reversible inhibitor of the proteasome, which has been mainly investigated as treatment of multiple myeloma. In a preclinical cell line model for TNBC the first-generation proteasome inhibitor bortezomib showed synergistic efficacy with cisplatin. Clinical data are available for carboplatin plus bortezomib in metastatic ovarian and lung cancers showing remarkable antitumor activity (47% and 38% response rate, respectively) and good tolerability. In solid tumors cytotoxic effect of proteasome inhibitors is thought to be mediated through different mechanisms: (1) Inhibition of the Fanconi Anemia and BRCA1 DNA repair mechanism (2) Inhibition of p53 degradation (3) Inhibition of NF-kappa B signaling cascade. Based on this evidence, the phase I/II MBC-10 trial will evaluate the toxicity profile and efficacy of the oral second-generation proteasome inhibitor ixazomib in combination with carboplatin in patients with advanced TNBC. Trial Design: Patients with metastatic TNBC pretreated with at least one prior line of chemotherapy for advanced disease with a confirmed disease progression and measurable disease are eligible for this study.Patients will receive ixazomib in combination with carboplatin on days 1, 8, and 15 in a 28-day cycle. The phase I part of this study uses an alternate dose escalation accelerated titration design. After establishing the maximum tolerated dose (MTD), accrual continues to evaluate the efficacy and safety of the combination (phase II, including 41 evaluable patients). All patients will continue on study drugs until disease progression, unacceptable toxicity or discontinuation for any other reason. Primary endpoint of the phase II is overall response rate, secondary endpoints include safety profile, progression-free survival and quality of life. The MBC-10 trial is accompanied by a broad biomarker program investigating predictive biomarkers for treatment response and potential resistance mechanisms to the investigational drug combination. This trial is open for patient enrollment since November 2016 in six Austrian cancer centers. Accrual is planned to be completed within two years. ClinicalTrials.gov Identifier: NCT02993094

Citation Format: Rinnerthaler G, Gampenrieder SP, Petzer A, Burgstaller S, Voskova D, Rossmann D, Balic M, Egle D, Rumpold H, Singer CF, Petru E, Melchardt T, Ulmer H, Mlineritsch B, Greil R. Ixazomib in combination with carboplatin in pretreated women with advanced triple negative breast cancer, an ongoing phase I/II trial (AGMT MBC-10 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 OT3-07-01.

Radiologic complete response (rCR) in contrast-enhanced magnetic resonance imaging (CE-MRI) after neoadjuvant chemotherapy for early breast cancer predicts recurrence-free survival but not pathologic complete response (pCR)

Background

Patients with early breast cancer (EBC) achieving pathologic complete response (pCR) after neoadjuvant chemotherapy (NACT) have a favorable prognosis. Breast surgery might be avoided in patients in whom the presence of residual tumor can be ruled out with high confidence. Here, we investigated the diagnostic accuracy of contrast-enhanced MRI (CE-MRI) in predicting pCR and long-term outcome after NACT.

Methods

Patients with EBC, including patients with locally advanced disease, who had undergone CE-MRI after NACT, were retrospectively analyzed (n = 246). Three radiologists, blinded to clinicopathologic data, reevaluated all MRI scans regarding to the absence (radiologic complete remission; rCR) or presence (no-rCR) of residual contrast enhancement. Clinical and pathologic responses were compared categorically using Cohen’s kappa statistic. The Kaplan-Meier method was used to estimate recurrence-free survival (RFS) and overall survival (OS).

Results

Overall rCR and pCR (no invasive tumor in the breast and axilla (ypT0/is N0)) rates were 45% (111/246) and 29% (71/246), respectively. Only 48% (53/111; 95% CI 38–57%) of rCR corresponded to a pCR (= positive predictive value - PPV). Conversely, in 87% (117/135; 95% CI 79–92%) of patients, residual tumor observed on MRI was pathologically confirmed (= negative predictive value - NPV). Sensitivity to detect a pCR was 75% (53/71; 95% CI 63–84%), while specificity to detect residual tumor and accuracy were 67% (117/175; 95% CI 59–74%) and 69% (170/246; 95% CI 63–75%), respectively. The PPV was significantly lower in hormone-receptor (HR)-positive compared to HR-negative tumors (17/52 = 33% vs. 36/59 = 61%; P = 0.004). The concordance between rCR and pCR was low (Cohen’s kappa − 0.1), however in multivariate analysis both assessments were significantly associated with RFS (rCR P = 0.037; pCR P = 0.033) and OS (rCR P = 0.033; pCR P = 0.043).

Conclusion

Preoperative CE-MRI did not accurately predict pCR after NACT for EBC, especially not in HR-positive tumors. However, rCR was strongly associated with favorable RFS and OS.

Electronic supplementary material

The online version of this article (10.1186/s13058-018-1091-y) contains supplementary material, which is available to authorized users.

ASCO 2018 highlights: metastatic breast cancer

This article reviews the clinically most relevant presentations at the American Society of Clinical Oncology (ASCO) annual meeting 2018 on the topic of metastatic breast cancer. In the randomized placebo-controlled phase 3 trial MONALEESA-3, testing ribociclib vs. placebo in combination with fulvestrant in postmenopausal women or men with hormone receptor-positive (HR+) and HER2-negative (HER2−) advanced breast cancer (ABC), an increase of median progression-free survival (PFS) from 12.8 months to 20.5 months by the addition of the CDK4/6 inhibitor was reported (HR 0.59; P > 0.01). Taselisib, an alpha specific PI3K inhibitor, was tested in combination with fulvestrant in pretreated HR+/HER2− ABC patients with PIK3CA mutations in the placebo-controlled phase 3 trial SANDPIPER. PFS was significantly longer (7.4 months vs 5.4 months; HR 0.70, P < 0.01) but severe adverse events were more frequent (32% and 9%) in the taselisib group. In triple-negative breast cancer, the AKT inhibitor capivasertib (AZD5363) was combined with paclitaxel as first-line treatment in the placebo-controlled phase 2 trial PAKT. In patients with altered PIK3CA, AKT1 or PTEN, median PFS increased from 3.7 months to 9.3 months (HR 0.30; two-sided P = 0.01). No treatment effect was shown in the non-altered group. The most common adverse events attributed to capivasertib were diarrhea, fatigue and stomatitis. Results of two phase I trials of trastuzumab antibody-drug conjugates (ADCs) indicated HER2 as a non-oncogenic surface target in breast cancer patients expressing HER2.

Supervised versus autonomous exercise training in breast cancer patients: A multicenter randomized clinical trial

Background

There is a well‐known correlation between obesity, sedentary lifestyle, and breast cancer incidence and outcome. The Arbeitsgemeinschaft Medikamentöse Tumortherapie (AGMT) exercise study was a multicenter, randomized clinical trial and assessed the feasibility and efficacy of physical training in 50 breast cancer patients undergoing aromatase inhibitor treatment.

Methods

Postmenopausal, estrogen receptor‐positive breast cancer patients under aromatase inhibitor treatment were randomized 1:1 to counseling and unsupervised training for 48 weeks (unsupervised arm) or counseling and a sequential training (supervised arm) with a supervised phase (24 weeks) followed by unsupervised physical training (further 24 weeks). Primary endpoint was the individual maximum power output on a cycle ergometer after 24 weeks of exercise. A key secondary endpoint was the feasibility of achieving 12 METh/week (metabolic equivalent of task hours per week).

Results

Twenty‐three patients (92%) in the unsupervised arm and 19 patients (76%) in the supervised arm with early‐stage breast cancer completed the study. After 24 weeks, the supervised arm achieved a significantly higher maximum output in watt (mean 132 ±  standard deviation [SD] 34; 95% confidence interval [CI] 117‐147) compared to baseline (107 ± 25; 95%CI 97‐117; P = 0.012) with a numerically higher output than the unsupervised arm (week 24 115 ± 25; 95%CI 105‐125; P = 0.059). Significantly higher METh/week was reported in the supervised arm compared to the unsupervised arm during the whole study period (week 1‐24 unsupervised: 18.3 (7.6‐58.3); supervised: 28.5 (6.7‐40.1); P = 0.043; week 25‐48; P = 0.041)).

Conclusion

This trial indicates that patients in an exercise program achieve higher fitness levels during supervised than unsupervised training.

Ixazomib in combination with carboplatin in pretreated women with advanced triple-negative breast cancer, a phase I/II trial of the AGMT (AGMT MBC-10 trial)

Background

Triple-negative breast cancer (TNBC) comprises a heterogeneous group of diseases which are generally associated with poor prognosis. Up to now, no targeted treatment beyond anti-VEGF therapy has been approved for TNBC and cytotoxic agents remain the mainstay of treatment. Ixazomib is a selective and reversible inhibitor of the proteasome, which has been mainly investigated in the treatment of multiple myeloma. In a preclinical study TNBC cells were treated with the first-generation proteasome inhibitor bortezomib in combination with cisplatin and synergistic efficacy was demonstrated. Clinical data are available for carboplatin plus bortezomib in metastatic ovarian and lung cancers showing remarkable antitumor activity and good tolerability (Mol Cancer 11:26 2012, J Thorac Oncol 4:87–92 2009, J Thorac Oncol 7:1032–1040, 2012). Based on this evidence, the phase I/II MBC-10 trial will evaluate the toxicity profile and efficacy of the second-generation proteasome inhibitor ixazomib in combination with carboplatin in patients with advanced TNBC.

Methods

Patients with metastatic TNBC pretreated with at least one prior line of chemotherapy for advanced disease with a confirmed disease progression and measurable disease according to RECIST criteria 1.1 are eligible for this study. Patients will receive ixazomib in combination with carboplatin on days 1, 8, and 15 in a 28-day cycle. The phase I part of this study utilizes an alternate dose escalation accelerated titration design. After establishing the maximum tolerated dose (MTD), the efficacy and safety of the combination will be further evaluated (phase II, including 41 evaluable patients). All patients will continue on study drugs until disease progression, unacceptable toxicity or discontinuation for any other reason. Primary endpoint of the phase II is overall response rate, secondary endpoints include progression-free survival, safety, and quality of life. This trial is open for patient enrollment since November 2016 in six Austrian cancer centers. Accrual is planned to be completed within 2 years.

Discussion

Based on preclinical and clinical findings an ixazomib and carboplatin combination is thought to be effective in metastatic TNBC patients. The MBC-10 trial is accompanied by a broad biomarker program investigating predictive biomarkers for treatment response and potential resistance mechanisms to the investigational drug combination.

Trial registration

EudraCT Number: 2016–001421-13 received on March 31, 2016, ClinicalTrials.gov Identifier: NCT02993094 first posted on December 15, 2016. This trial was registered prospectively.

Cure in metastatic breast cancer

Oligometastatic disease characterizes a distinct subgroup of metastatic breast cancer patients that might benefit from different treatment strategies to achieve long-lasting remission and potentially cure. Those long-lasting remissions are reported after locoregional treatment of the primary tumor and all metastatic sites in several case series; however, unlike other tumor entities, prospective data are lacking. Furthermore, tumor eradication by excellent systemic anticancer therapy with novel chemotherapies and targeted agents can lead to long-term survival. In addition, reactivation of the host immune defense by immuno-oncologic drugs can achieve long-lasting tumor control. So far, unfortunately, checkpoint inhibitors as monotherapy have led to responses only in a small percentage of patients with metastatic breast cancer. This short review summarizes available data on long-lasting remissions and potential cure in metastatic breast cancers. It describes and discusses data on locoregional treatment, chemo-, antibody- and immunotherapy and tries to select individual patients for whom a multidisciplinary treatment approach with curative intention might be an option to achieve long-term survival.

DNA Methylation Signatures Predicting Bevacizumab Efficacy in Metastatic Breast Cancer

Background: Biomarkers predicting response to bevacizumab in breast cancer are still missing. Since epigenetic modifications can contribute to an aberrant regulation of angiogenesis and treatment resistance, we investigated the influence of DNA methylation patterns on bevacizumab efficacy. Methods: Genome-wide methylation profiling using the Illumina Infinium HumanMethylation450 BeadChip was performed in archival FFPE specimens of 36 patients with HER2-negative metastatic breast cancer treated with chemotherapy in combination with bevacizumab as first-line therapy (learning set). Based on objective response and progression-free survival (PFS) and considering ER expression, patients were divided in responders (R) and non-responders (NR). Significantly differentially methylated gene loci (CpGs) with a strong change in methylation levels (Δβ>0.15 or Δβ<-0.15) between R and NR were identified and further investigated in 80 bevacizumab-treated breast cancer patients (optimization set) and in 15 patients treated with chemotherapy alone (control set) using targeted deep amplicon bisulfite sequencing. Methylated gene loci were considered predictive if there was a significant association with outcome (PFS) in the optimization set but not in the control set using Spearman rank correlation, Cox regression, and logrank test. Results: Differentially methylated loci in 48 genes were identified, allowing a good separation between R and NR (odds ratio (OR) 101, p<0.0001). Methylation of at least one cytosine in 26 gene-regions was significantly associated with progression-free survival (PFS) in the optimization set, but not in the control set. Using information from the optimization set, the panel was reduced to a 9-gene signature, which could divide patients from the learning set into 2 clusters, thereby predicting response with an OR of 40 (p<0.001) and an AUC of 0.91 (LOOCV). A further restricted 3-gene methylation model showed a significant association of predicted responders with longer PFS in the learning and optimization set even in multivariate analysis with an excellent and good separation of R and NR with AUC=0.94 and AUC=0.86, respectively. Conclusion: Both a 9-gene and 3-gene methylation signature can discriminate between R and NR to a bevacizumab-based therapy in MBC and could help identify patients deriving greater benefit from bevacizumab.

Abstract OT2-07-11: Ixazomib in combination with carboplatin in pretreated women with advanced triple negative breast cancer, a phase I/II trial (AGMT MBC-10 trial)

Background: Triple-negative breast cancer (TNBC) comprises a heterogeneous group of diseases which are generally associated with a poor prognosis. Up to now, no targeted treatment beyond anti-VEGF therapy is approved for TNBC so far and cytotoxic agents are the mainstay for the treatment of advanced tumor stages. Ixazomib is a selective, and reversible inhibitor of the proteasome, which has been mainly investigated in the treatment of multiple myeloma. In a preclinical study triple-negative breast cancer cells were treated with bortezomib, a first generation proteaseome inhibitor, alone and in combination with cisplatin, which had a synergistic effect. Clinical data are available for carboplatin plus bortezomib in metastatic ovarian and lung cancers showing remarkable antitumor activity and good tolerability. Based on this rational, the MBC-10 trial will evaluate the toxicity profile and efficacy of ixazomib in combination with carboplatin in patients with advanced TNBC.

Trial Design: Patients with metastatic TNBC pretreated with at least one prior line of chemotherapy for advanced disease with a confirmed disease progression and measurable disease are eligible for this study. Patients will receive ixazomib in combination with carboplatin on days 1, 8, and 15 in a 28-day cycle. The phase I part of this study uses an alternate dose escalation accelerated titration design. After establishing the maximum tolerated dose (MTD), accrual continues to evaluate the efficacy and safety of the combination (phase II, including 41 evaluable patients). All patients will continue on study drugs until disease progression, unacceptable toxicity or discontinuation for any other reason. Primary endpoint of the phase II is overall response rate, secondary endpoints include safety profile, progression-free survival and quality of life. This trial is open for patient enrollment since November 2016 in six Austrian cancer centers. Accrual is planned to be completed within two years. ClinicalTrials.gov Identifier: NCT02993094

Citation Format: Rinnerthaler G, Gampenrieder SP, Petzer A, Pusch R, Fridrik M, Rossmann D, Balic M, Egle D, Rumpold H, Singer C, Bartsch R, Melchardt T, Ulmer H, Mlineritsch B, Greil R. Ixazomib in combination with carboplatin in pretreated women with advanced triple negative breast cancer, a phase I/II trial (AGMT MBC-10 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 OT2-07-11.

Abstract P4-02-02: Contrast-enhanced MRI does not accurately predict pathologic complete response (pCR) after neoadjuvant chemotherapy in early or locally advanced breast cancer

Background: Patients with early or locally advanced breast cancer achieving a pathologic complete response (pCR) after neoadjuvant chemotherapy have a lower risk for recurrence or death compared to patients with residual invasive cancer. In the future, breast surgery might be avoided in patients in whom the presence of residual tumor after neoadjuvant therapy can be ruled out with very high confidence. Magnetic resonance imaging (MRI) has been shown to be the most accurate radiologic tool in breast cancer diagnostics and follow-up care. Therefore, we investigated the diagnostic accuracy of contrast-enhanced MRI to predict a pathological complete remission after neoadjuvant chemotherapy.

Methods: This retrospective study included all non-metastatic breast cancer patients treated with neoadjuvant chemotherapy followed by a contrast-enhanced MRI and breast cancer surgery at our institution between 09/2006 and 05/2016. Three specialized breast radiologists, blinded to the clinical and pathological data, reevaluated all preoperative MRI scans and recorded the presence or absence of contrast enhancement as indicator for residual cancer. pCR was defined as no invasive tumor in breast and axilla (ypT0/is N0), however 3 alternative definitions were investigated as well (ypT0 N0, ypT0/is and ypT). Cross tables were used to calculate sensitivity, specificity, pCR-predictive value (PPV), non-pCR-predictive value (NPV) and accuracy. P-values reflecting PPV and NPV differences between various patient subgroups were calculated with Fisher's exact test. The Kaplan-Meier method was used for estimates of distant-recurrence-free survival (DRFS) and overall survival (OS).

Results: In total, 246 patients fulfilled the inclusion criteria and were evaluated. Overall pCR and radiologic complete remission (rCR) rate were 29% and 45%, respectively. Only 48% of rCR corresponded to a pCR (PPV). Conversely, in 87% of cases, residual tumor in the MRI was pathologically confirmed (NPV). The sensitivity to detect a pCR was 75%, while specificity and accuracy were 67% and 69%, respectively. The diagnostic performance of MRI to predict treatment response varied between different histologic and molecular tumor subtypes, however there were little differences between the 4 pCR definitions. The PPV was significantly lower in the hormone-receptor(HR)-positive subgroup compared with the HR-negative subgroup (33% vs. 61%; P = 0.004), especially in luminal-A-like (7%) and lobular carcinomas (0%), respectively. Despite the low concordance (Kohens kappa -0.1), the prognostic value for distant recurrence-free survival was similar between rCR (HR 0.29) and pCR (HR 0.27), respectively. The median pathologic tumor size of residual disease in false-positive cases (rCR but no pCR) was 0.7 cm (SD 0.98 cm).

Conclusion: Contrast-enhanced MRI does not accurately predict pCR after neoadjuvant chemotherapy in early or locally advanced breast cancer, especially in HR-positive tumors. However, in case of false rCR the dimension of residual disease is generally small. Since residual tumor tissue can be detected with high precision, preoperative breast MRI is still of value for operation planning.

Citation Format: Gampenrieder SP, Peer A, Weismann C, Meissnitzer M, Rinnerthaler G, Webhofer J, Westphal T, Popovscaia M, Meissnitzer T, Reitsamer R, Hauser-Kronberger C, Egger H, Hergan K, Mlineritsch B, Greil R. Contrast-enhanced MRI does not accurately predict pathologic complete response (pCR) after neoadjuvant chemotherapy in early or locally advanced 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 P4-02-02.

Antiangiogenic therapy in breast cancer

Based on a strong rationale for anti-VEGF (vascular endothelial growth factor) treatment in breast cancer and promising preclinical data, great hopes have been placed on the anti-VEGF antibody bevacizumab. Clinical trials, however, reported conflicting results. In metastatic human epidermal growth factor receptor 2(HER2)-negative breast cancer, the addition of bevacizumab to standard chemotherapy improved consistently progression-free survival (PFS), however, without effect on overall survival (OS). In early breast cancer bevacizumab increased the pathologic complete response rate (pCR) after neoadjuvant therapy, but adjuvant trials did not demonstrate an effect on long-term survival. Unfortunately, despite extensive research, there is still no biomarker for bevacizumab efficacy available, making patient selection difficult. This review summarizes all phase III trials investigating efficacy and toxicity of bevacizumab in early, locally advanced and metastatic breast cancer. It recapitulates the main toxicities, gives an overview on biomarker studies and discusses the role and future aspects of antiangiogenic therapy in breast cancer.

SABCS 2016: systemic therapy for metastatic breast cancer

At the 2016 San Antonio Breast Cancer Symposium, several interesting phase II and phase III studies investigating systemic therapies for metastatic breast cancer were presented. The PrEGOC 0102 trial demonstrated that the combination of fulvestrant plus everolimus is safe and effective and could be an alternative to exemestane plus everolimus for selected patients with hormone-receptor positive, HER2-negative disease. The pan-PI3K inhibitor buparlisib showed some activity in combination with fulvestrant after failure of everolimus in the BELLE-3 trial. PIK3CA mutation detected in circulating tumor DNA (ctDNA) was predictive for a buparlisib efficacy. Unfortunately, the unfavorable toxicity profile precludes further development of this drug. Nonetheless, PI3K seems to be a valid target in tumors resistant to mTOR inhibition. The BROCADE phase II trial failed to show a statistically significant benefit by the addition of the PARP inhibitor veliparib to carboplatin and paclitaxel in patients with BRCA1/2 germline mutation. The overall response rate, however, was statistically significant higher in the veliparib arm compared to the placebo arm. Data from the phase III trial BROCADE-3 are awaited. Finally, the TNT trial did not identify further biomarkers, in addition to BRCA1/2 germline mutation, for carboplatin benefit in patients with metastatic triple-negative breast cancer.

Abstract P6-07-10: DNA methylation signature predicting bevacizumab efficacy in metastatic breast cancer

Background: Biomarkers predicting response to bevacizumab containing therapy in breast cancer are still missing. Since epigenetic modifications can contribute to an aberrant regulation of angiogenesis and to treatment resistance, we investigated the influence of DNA methylation on bevacizumab efficacy.

Patients and methods: A genome-wide methylation profiling using the Illumina Infinium HumanMethylation450 BeadChip was performed in archival FFPE specimen of 36 patients with HER2-negative metastatic breast cancer treated with chemotherapy in combination with bevacizumab as first-line therapy (learning set). Based on objective response and progression-free survival (PFS) and considering ER expression, patients were divided in responders (R) and non-responders (NR). Differentially methylated gene loci (methylation variable position = MVP) and differentially methylated regions (DMR) between R and NR were identified. Only significant sites with a strong change in methylation levels (Δβ&gt;0.15 or Δβ&lt;-0.15), an area under the curve of at least 0.85 by logistic regression analysis, and/or sites in proximity to genes functionally involved in angiogenesis and carcinogenesis were selected and further validated. Validation was performed in 81 bevacizumab treated breast cancer patients (validation set) and in 15 patients treated with chemotherapy only (control set) using targeted bisulfite sequencing. Methylated gene loci were considered predictive if there was a significant association with outcome (PFS) in the validation set but not in the control set using Spearman rank correlation, Cox regression, and logrank test.

Results: In the learning set 435 MVPs (p&lt;0.001) and 144 DMRs (adjusted combined p&lt;0.0001 with at least 3 significant MVPs p&lt;0.05 in the same region) showed significantly different methylation between R and NR. In R 152 sites were hypermethylated with a median change of methylation (Δβ) of 0.13; 283 sites were hypomethylated with a median Δβ of -0.09. A methylation signature of 48 genes was specified allowing a good separation between responders and non-responders (odds ratio=101, p&lt;0.0001; data presented at the 38th SABCS 2015, P3-07-43). At least one methylated cytosine in close proximity to 24 of these genes showed a significant association with PFS in the validation set but was not (or in the other direction) in the control set. Based on these data the methylation signature predicting long lasting response to bevacizumab could be reduced to 24 genes including several genes involved in angiogenesis and carcinogenesis, respectively (FLT1 also known as VEGFR-1, MLH1, GNAS, APC, DKK3, WNT2B and COL4A1).

Conclusion: A 24-gene methylation signature can reproducible discriminate between responders and non-responders to a bevacizumab-based therapy in breast cancer and could help to identify patients deriving greater benefit from anti-VEGF agents.

Citation Format: Gampenrieder SP, Rinnerthaler G, Pulverer W, Weinhäusel A, Hufnagl C, Hackl H, Hauser-Kronberger C, Mlineritsch B, Greil R. DNA methylation signature predicting bevacizumab efficacy in 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 P6-07-10.

Abstract P5-15-13: Capecitabine in combination with bendamustine in pretreated women with HER2-negative metastatic breast cancer: Final PFS results of a phase II trial (AGMT MBC-6)

Background: Capecitabine is a well-established treatment option in HER2-negative advanced breast cancer (ABC) patients. Bendamustine is a generally well tolerated cytotoxic drug. Since bendamustine has already shown anticancer activity in ABC we evaluated the efficacy and tolerability of bendamustine in combination with capecitabine in pretreated patients with ABC. Here we present the final PFS results of this phase II trial.

Patients and methods: MBC-6 is a non-randomized, multicenter, open-label, single-arm phase II study in patients with HER2-negative ABC (ClinicalTrials.gov: NCT01891227). All patients were pretreated with anthracyclines and/or taxans and had measurable disease according to RECIST 1.1. Patients received 1000 mg/m2 capecitabine twice daily on days 1 to 14 in combination with 80 mg/m2 bendamustine on day 1 and 8 of a 3-week cycle for a maximum of 6 cycles. Afterwards capecitabine was continued as monotherapy. The primary endpoint was overall response rate (ORR). Secondary endpoints were progression-free survival (PFS), clinical benefit rate (CBR), safety and quality of life.

Results: From September 2013 to May 2015, 40 patients were recruited in eight Austrian centers. Median age was 60 years (range 29-77). Twenty-five percent of patients had triple-negative disease (TNBC) and 93% showed visceral involvement. Sixty-five percent had received prior chemotherapy in the (neo)adjuvant setting and 63% for ABC (43% one line, 15% two lines, 5% three lines). All patients with ER-positive disease had received prior endocrine therapy.At data cut-off on 06/08/16 overall 39 of 40 patients had discontinued treatment with a median PFS of 7.0 months (95% CI 4.6-9.5), 7.4 months in ER-positive and 4.0 months in triple negative disease (TNBC), respectively. Twelve patients (30%) experienced at least one drug related non-hematological AE ≥ grade 3 during combination treatment and further 6 patients (15%) during capecitabine maintenance. Three grade 4 hematological AEs (neutropenia) were observed. One patient died as a result of restrictive cardiomyopathy, where a relationship to capecitabine cannot be excluded, but seems unlikely.

Conclusion: The combination of capecitabine and bendamustine shows promising efficacy and a moderate toxicity profile. Further evaluation of this drug combination is warranted.Background: Capecitabine is a well-established treatment option in HER2-negative advanced breast cancer (ABC) patients. Bendamustine is a generally well tolerated cytotoxic drug. Since bendamustine has already shown anticancer activity in ABC we evaluated the efficacy and tolerability of bendamustine in combination with capecitabine in pretreated patients with ABC. Here we present the final PFS results of this phase II trial.

Patients and methods: MBC-6 is a non-randomized, multicenter, open-label, single-arm phase II study in patients with HER2-negative ABC (ClinicalTrials.gov: NCT01891227). All patients were pretreated with anthracyclines and/or taxans and had measurable disease according to RECIST 1.1. Patients received 1000 mg/m2 capecitabine twice daily on days 1 to 14 in combination with 80 mg/m2 bendamustine on day 1 and 8 of a 3-week cycle for a maximum of 6 cycles. Afterwards capecitabine was continued as monotherapy. The primary endpoint was overall response rate (ORR). Secondary endpoints were progression-free survival (PFS), clinical benefit rate (CBR), safety and quality of life.

Results: From September 2013 to May 2015, 40 patients were recruited in eight Austrian centers. Median age was 60 years (range 29-77). Twenty-five percent of patients had triple-negative disease (TNBC) and 93% showed visceral involvement. Sixty-five percent had received prior chemotherapy in the (neo)adjuvant setting and 63% for ABC (43% one line, 15% two lines, 5% three lines). All patients with ER-positive disease had received prior endocrine therapy.At data cut-off on 06/08/16 overall 39 of 40 patients had discontinued treatment with a median PFS of 7.0 months (95% CI 4.6-9.5), 7.4 months in ER-positive and 4.0 months in triple negative disease (TNBC), respectively. Twelve patients (30%) experienced at least one drug related non-hematological AE ≥ grade 3 during combination treatment and further 6 patients (15%) during capecitabine maintenance. Three grade 4 hematological AEs (neutropenia) were observed. One patient died as a result of restrictive cardiomyopathy, where a relationship to capecitabine cannot be excluded, but seems unlikely.

Conclusion: The combination of capecitabine and bendamustine shows promising efficacy and a moderate toxicity profile. Further evaluation of this drug combination is warranted.

Citation Format: Rinnerthaler G, Gampenrieder SP, Voskova D, Petzer A, Hubalek M, Petru E, Hartmann B, Andel J, Balic M, Melchardt T, Ulmer H, Mlineritsch B, Greil R. Capecitabine in combination with bendamustine in pretreated women with HER2-negative metastatic breast cancer: Final PFS results of a phase II trial (AGMT MBC-6) [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 P5-15-13.

CDK4/6 inhibition in luminal breast cancer

Endocrine therapy represents the basis for the treatment of estrogen receptor-positive breast cancer, but several tumors harbor intrinsic resistance and acquired resistance to endocrine therapy is inevitable in metastatic disease. Combination strategies of endocrine therapy with targeted agents are aimed to overcome endocrine resistance. The selective CDK4/6 inhibitor palbociclib has shown promising results in metastatic luminal breast cancer when used in combination with endocrine therapy both in the first-line setting as in pretreated women. The drug showed a manageable safety profile with uncomplicated neutropenia as the most frequent side effect. Approval was already granted in the US and is also awaited during 2016 for Europe.

Abstract P1-13-10: Capecitabine in combination with bendamustine in pretreated women with HER2-negative metastatic breast cancer: Stage 1 results of a phase II trial (AGMT MBC-6)

Background: Although there is no single accepted standard of care after failure of anthracycline and taxane therapy in HER2-negative metastatic breast cancer, capecitabine is a well-established treatment option. Bendamustine is a hybrid cytotoxic drug because of its structural similarity to alkylating agents and purine and it is generally well tolerated. Since bendamustine has already shown anticancer activity in breast cancer we evaluated the efficacy and tolerability of bendamustine in combination with capecitabine in 40 patients with advanced breast cancer after anthracycline and/or taxane pretreatment.

Patients and methods: MBC-6 is a non-randomized, multicenter, open-label, single-arm phase II study in patients with HER2-negative advanced breast cancer (ClinicalTrials.gov identifier: NCT01891227). All patients were pretreated with anthracyclines and/or taxans in the (neo-)adjuvant and/or metastatic setting and measurable disease according to RECIST 1.1. had to be present at baseline. Following a two-stage Green-Dahlberg design, 20 subjects were accrued and treated within stage 1 of the study. The trial was planned to enroll further 20 patients if there were at least four subjects (20%) with a complete (CR) or partial response (PR). Eligible patients received 1000 mg/m2 capecitabine twice daily on days 1 to 14 in combination with 80 mg/m2 bendamustine on day 1 and 8 of a 3-week cycle. After a maximum of eight cycles capecitabine was continued as single drug therapy until disease progression or unacceptable toxicity. The primary endpoint was overall response rate (ORR). Secondary endpoints were progression free survival (PFS), clinical benefit rate (CBR), safety profile and quality of life. Here we report the efficacy and safety analysis of stage 1 patients.

Results: From September 2013 to May 2015, 40 patients were recruited in eight Austrian centers. Median age of the stage 1 cohort was 59 years (range 29-77), 80% and 20% of patients had an ECOG performance score of 0 and 1, respectively. Thirty-three percent had triple-negative disease, 85% had had (neo-)adjuvant treatment and 65% patients were pretreated with at least one chemotherapy line for metastatic disease (15% one line, 50% two lines, 40% three lines). In stage 1, ORR was 50% with 9 confirmed PR and 1 confirmed CR, and ORR was comparable between hormone receptor-positive and triple-negative disease (54% vs. 43%). CBR was 55%. At data cut-off on 05/28/15 overall 15 of 20 patients had discontinued treatment: 10 patients (50%) due to progressive disease, 3 (15%) because of adverse events (AEs) and 2 patients on their own decision (10%). Five patients (25%) experienced at least one drug related non-hematological AE ≥ grade 3: 2 diarrhea, 2 fatigue, 3 respiratory or viral infections, 1 dyspnea, 1 thromboembolic event (each grade 3). One grade 4 hematological AE (neutropenia) was observed. One patient died as a result of restrictive cardiomyopathy, where a relationship to capecitabine cannot be excluded, but seems unlikely.

Conclusion: The combination of capecitabine and bendamustine has a moderate toxicity profile and the response data of the stage 1 are promising. Final study results are awaited in the first half of 2016.

Citation Format: Rinnerthaler G, Gampenrieder SP, Fridrik M, Petzer A, Hubalek M, Petru E, Jäger T, Andel J, Balic M, Ulmer H, Mlineritsch B, Greil R. Capecitabine in combination with bendamustine in pretreated women with HER2-negative metastatic breast cancer: Stage 1 results of a phase II trial (AGMT MBC-6). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-13-10.

Abstract P3-07-43: DNA methylation patterns correlating with outcome in patients treated with first-line bevacizumab for metastatic breast cancer

Background: Biomarkers predicting response to bevacizumab containing therapy in breast cancer are of urgent need for a personalized treatment approach. DNA methylation is involved in regulation of angiogenesis and development of treatment resistance and could therefore provide predictive information for bevacizumab efficacy.

Patients and methods: A genome-wide methylation profiling using the Illumina Infinium HumanMethylation450 BeadChip was performed in FFPE specimen of 36 patients with HER2-negative metastatic breast cancer treated with chemotherapy in combination with bevacizumab as first-line therapy (discovery set). Twenty-eight (78%) samples came from primary tumor and 8 (22%) from metastasis (2 lung mets., 1 pleural met., 1 liver met., 2 soft tissue mets., 1 ovarial met, 1 bone marrow infiltration). Based on progression-free survival (PFS) and breast cancer subtype (ER+ vs. triple-negative) patients were divided in responder (R) and non-responder (NR). By biostatistical methods differences in the methylation pattern between R and NR were detected. The 48 most interesting genes (e.g. because of there involvement in angiogenesis or carcinogenesis) showing a differential methylation status between R and NR are currently validated in two further metastatic breast cancer cohorts treated with (main set) and without bevacizumab (validation set), respectively. These validated results will be presented at the meeting.

Citation Format: Gampenrieder SP, Rinnerthaler G, Weinhäusel A, Pulverer W, Hugnagl C, Hackl H, Romeder F, Monzo Fuentes C, Hauser-Kronberger C, Mlineritsch B, Greil R. DNA methylation patterns correlating with outcome in patients treated with first-line bevacizumab for metastatic breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-07-43.

Lapatinib-plus-pegylated liposomal doxorubicin in advanced HER2-positive breast cancer following trastuzumab: a phase II trial

BACKGROUND

Trastuzumab, one important treatment option for HER2-positive metastatic breast cancer (MBC) is limited by its cardiotoxic potential. Lapatinib and pegylated liposomal doxorubicin (PLD) represent a cardiosparing alternative that can cross the blood brain barrier. This is important, because one third of breast cancer patients develop brain metastases.

PATIENTS AND METHODS

We included 24 patients with HER2-positive MBC progressing under trastuzumab. They received 1,250 mg lapatinib daily until progression plus PLD (40 mg/m(2)) every 4 weeks for maximal 6 cycles. The primary end-point was the overall response rate (ORR). Secondary end-points were progression-free survival (PFS), overall survival (OS), 1-year PFS and 1-year OS rates.

RESULTS

ORR was 54%. Median PFS was 5.8 and median OS 23.3 months. The one-year PFS rate was 27% and 1-year OS rate 76%.

CONCLUSION

Lapatinib-plus-PLD is active and safe in HER2-positive MBC, especially suitable for patients with cardiological risk or brain metastases.

Hypertension as a predictive marker for bevacizumab in metastatic breast cancer: results from a retrospective matched-pair analysis

BACKGROUND

Several phase-III studies have shown improvements in terms of progression-free survival (PFS) with bevacizumab when added to chemotherapy in advanced breast cancer. However, the extent of improvement varied and none of the trials showed benefit in terms of overall survival (OS).

PATIENTS AND METHODS

All patients with metastatic breast cancer treated with bevacizumab at our Institution between 2005 and 2011 were retrospectively analyzed. A control group was matched according to the following variables: receptor status, treatment line, type of chemotherapy, presence of visceral disease and age.

RESULTS

All 212 patients were evaluable for toxicity, and 198 for response; 430 controls allowed a complete matching for 85 bevacizumab-treated patients. The addition of bevacizumab to chemotherapy significantly prolonged PFS (9.3 vs. 7.6 months, hazard ratio [HR]=0.70, 95% confidence interval [CI]=0.51-0.97, p=0.031) and OS (28.9 vs. 22.6 months, HR=0.67, 95% CI=0.45-0.99, p=0.043). Clinical benefit rate (overall response rate + stable disease for at least six months) was significantly better in the bevacizumab group (75% vs. 59%, p=0.002), while ORR did not differ significantly (48% vs. 35%, p=0.21). Patients developing hypertension during treatment had a more favourable outcome (PFS 13.7 vs. 6.6 months, HR=0.34, 95% CI=0.23-0.49 p<0.001; 2-year OS 78% vs. 30%, HR=0.20, 95% CI=0.12-0.35, p<0.001).

CONCLUSION

Bevacizumab in addition to chemotherapy prolonged PFS and OS in a non-selected, partly intensively pre-treated breast cancer population. Hypertension induced by bevacizumab predicted therapy efficacy.

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

BACKGROUND

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

CLINICAL TRIAL NUMBER

NCT00309556, www.clinicaltrials.gov.

Abstract P5-20-11: Bevacizumab in metastatic breast cancer: a retrospective matched-pair analysis

Background: In November 2011 the FDA withdrew accelerated approval of the breast cancer indication for bevacizumab, because “the drug has not been shown to be safe and effective for this use” (FDA Commissioner M. A. Hamburg, MD). The objective of this analysis was to evaluate efficacy and safety of bevacizumab in non-selected patients with stage IV breast cancer.

Patients and methods: All patients with metastatic breast cancer treated with bevacizumab in combination with chemotherapy in our institution between 2005 and 2011 were retrospectively analysed. At least 1 cycle of bevacizumab was required for safety analysis, 3 applications for efficacy evaluation. A control group was matched according to the following criteria: receptor status, line of treatment, chemotherapy backbone, visceral or non-visceral disease and age.

Results: A total of 213 patients fulfilled the inclusion criteria. All of them were evaluable for toxicity, 199 for response. 503 potential controls allowed a complete matching for 103 patients. Fifty-eight percent of patients received first-line, 15% second-line and 27% of patients beyond second-line treatment. Visceral metastases were present in 69% of patients in both groups. The most common chemotherapy backbones were paclitaxel, capecitabine and docetaxel with 44%, 32% and 19%, respectively.