The BRCA1ness signature is associated significantly with response to PARP inhibitor treatment versus control in the I-SPY 2 randomized neoadjuvant setting.


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Authors
Severson, Tesa M 
Wolf, Denise M 
Yau, Christina 
Peeters, Justine 
Wehkam, Diederik 
Abstract

BACKGROUND: Patients with BRCA1-like tumors correlate with improved response to DNA double-strand break-inducing therapy. A gene expression-based classifier was developed to distinguish between BRCA1-like and non-BRCA1-like tumors. We hypothesized that these tumors may also be more sensitive to PARP inhibitors than standard treatments. METHODS: A diagnostic gene expression signature (BRCA1ness) was developed using a centroid model with 128 triple-negative breast cancer samples from the EU FP7 RATHER project. This BRCA1ness signature was then tested in HER2-negative patients (n = 116) from the I-SPY 2 TRIAL who received an oral PARP inhibitor veliparib in combination with carboplatin (V-C), or standard chemotherapy alone. We assessed the association between BRCA1ness and pathologic complete response in the V-C and control arms alone using Fisher's exact test, and the relative performance between arms (biomarker × treatment interaction, likelihood ratio p < 0.05) using a logistic model and adjusting for hormone receptor status (HR). RESULTS: We developed a gene expression signature to identify BRCA1-like status. In the I-SPY 2 neoadjuvant setting the BRCA1ness signature associated significantly with response to V-C (p = 0.03), but not in the control arm (p = 0.45). We identified a significant interaction between BRCA1ness and V-C (p = 0.023) after correcting for HR. CONCLUSIONS: A genomic-based BRCA1-like signature was successfully translated to an expression-based signature (BRC1Aness). In the I-SPY 2 neoadjuvant setting, we determined that the BRCA1ness signature is capable of predicting benefit of V-C added to standard chemotherapy compared to standard chemotherapy alone. TRIAL REGISTRATION: I-SPY 2 TRIAL beginning December 31, 2009: Neoadjuvant and Personalized Adaptive Novel Agents to Treat Breast Cancer (I-SPY 2), NCT01042379 .

Description
Keywords
BRCAness, Breast cancer, Neoadjuvant, PARP inhibition, Triple-negative breast cancer, Antineoplastic Combined Chemotherapy Protocols, BRCA1 Protein, Biomarkers, Tumor, Breast Neoplasms, Chemotherapy, Adjuvant, Cluster Analysis, Female, Gene Expression Profiling, Gene Expression Regulation, Neoplastic, Gene Regulatory Networks, Humans, Neoadjuvant Therapy, Poly(ADP-ribose) Polymerase Inhibitors, Sensitivity and Specificity, Treatment Outcome, Triple Negative Breast Neoplasms
Journal Title
Breast Cancer Res
Conference Name
Journal ISSN
1465-5411
1465-542X
Volume Title
Publisher
Springer Science and Business Media LLC
Sponsorship
Department of Health (via National Institute for Health Research (NIHR)) (unknown)
European Commission FP7 Network of Excellence (NoE) (260791)
European Commission FP7 Collaborative projects (CP) (258967)
Department of Health (via National Institute for Health Research (NIHR)) (NF-SI-0515-10090)
European Commission (258967)