284P - Real-life study of BRCA genetic screening in metastatic breast cancer

Date 11 September 2017
Event ESMO 2017 Congress
Session Poster display session
Topics Breast Cancer, Metastatic
Breast Cancer
Personalised Medicine
Presenter Guillaume Meynard
Citation Annals of Oncology (2017) 28 (suppl_5): v74-v108. 10.1093/annonc/mdx365
Authors G. Meynard1, C. Villanueva1, A. Thiery-Vuillemin1, L. Mansi1, P. Montcuquet1, N. Meneveau1, L. Chaigneau1, F. Bazan1, H. Almotlak1, E. Dobi1, T. Nguyen Tan Hon1, E. Klajer1, C. Fagnoni-Legat2, S. Paget-Bailly3, A. Meurisse3, M. Collonge-Rame4, C. Populaire-Ventron4, X. Pivot1, E. Curtit1
  • 1Medical Oncology, CHU Besançon, Hôpital Jean Minjoz, 25030 - Besançon/FR
  • 2Pharmacology Unit, CHU Besançon, Hôpital Jean Minjoz, 25030 - Besançon/FR
  • 3Methodological And Quality Of Life Unit In Oncology, University Hospital Jean Minjoz, 25000 - Besançon/FR
  • 4Genetic Unit, CHU Besançon, Hôpital Jean Minjoz, 25030 - Besançon/FR

Abstract

Background

Genomic instability is a hallmark of cancers and mutations in the DNA repair BRCA1 and BRCA2 genes predispose to breast and other cancers. Prevalence of BRCA1/2 mutations is known in general population, but the frequency of these mutations in patients with metastatic breast cancer has not been established.

Methods

Prospective BRCA1 and BRCA2 genetic testing was proposed to all patients with metastatic breast cancer treated in 7 centers (in Franche-Comte, France) between February 19th 2015 and November 30th. BRCA TrueTM test (Pathway Genomics®, San Diego CA, USA) was used to analyze the coding and flanking regions of BRCA1 and BRCA2 genes associated with hereditary breast and ovarian cancer by next-generation sequencing-base and Sanger sequencing.

Results

Of the 407 metastatic breast cancer patients, 11 (2.7%) had pathogenic germline BRCA1/2 mutations. BRCA2 (n = 8) mutations were the most frequent. Five of 11 patients (45%) would not have been candidate for BRCA1/2 mutation screening according to genetic counseling recommendations. All patients with a BRCA2 mutation presented a luminal metastatic breast cancer whereas all patients with BRCA1 mutation had a triple-negative metastatic breast cancer.

Conclusions

This is the first study assessing the prevalence of germline BRCA1 and BRCA2 mutations in an unselected population of patients with metastatic breast cancer. These patients with BRCA1/2 germline mutation represent the targeted population for poly(ADP-ribose) polymerase (PARP) inhibitors based therapy.

Clinical trial identification

Legal entity responsible for the study

University Hospital Jean Minjoz of Besancon, France

Funding

BioMarin

Disclosure

All authors have declared no conflicts of interest.