Abstract P5-03-06: Comparison of clinicopathological features and outcome of breast cancer in BRCA-mutation carriers, in patients with a family history without BRCA-mutation and in patients with sporadic disease

Abstract

Abstract BACKGROUND: BRCA1 and BRCA2 are two major susceptibility genes for breast cancer. We aimed to compare clinicopathological features and outcomes in BRCA1/2-mutation carriers patients, in patients with a family history suggesting hereditary breast cancer (HBC) without BRCA mutation (Eisinger score ≥ 5), and in patients with sporadic disease. METHODS: We retrospectively reviewed clinical and pathological data of 56 BRCA-mutation carriers (29 BRCA1, 27 BRCA2), 85 HBC patients and 70 sporadic breast cancer patients treated at Saint-Louis hospital between 1987 and 2017. Sporadic breast cancer patients were free from family history of cancer and randomly extracted from our database. We recorded age, clinicopathological features of breast tumors (tumor size, grade, nodal status, hormone receptor and c-erbB2 status), treatment type, ipsilateral relapse, contralateral breast cancer occurrence, distant metastasis and outcome (disease-free and overall survival). RESULTS: BRCA-mutated and HBC patients showed earlier age of onset of tumor (respectively 36, 42 and 40 years) than sporadic breast cancer patients (54 years, p<0.05). Relatives of HBC patients have developed significantly more different tumor-types than BRCA-mutated patient. BRCA1-mutated patients tumors were mostly triple-negative (62%, p<0,05) and grade 3 (83%, p<0,05), whereas the other groups presented mostly tumors of luminal subtype and grade 2. Of note, HBC and BRCA2-mutated patients shared similar clinical and pathological characteristics. Interestingly, HER2 overexpressed tumors were less represented in BRCA-mutated patients (4 and 10%) than in HBC and sporadic breast cancer patients (22% and 19%, p=0,06). BRCA1-mutated tumors were significantly more sensitive to chemotherapy, with a higher rate of clinicopathological complete response to neo-adjuvant chemotherapy (64%, p<0.05). BRCA1-mutated patients developed more contralateral breast cancers than sporadic breast cancer patients (p=0,01). No difference in RFS, DFMS or OS was observed between the different groups. CONCLUSION: clinicopathological characteristics and outcomes of HBC patients are similar to those of BRCA2-mutated patients. Ongoing multi-gene panel testing in this population will identify mutations in other relevant genes and provide new insights in genotype-phenotype correlation. Citation Format: Stéphanie Bécourt, Ludovic Doucet, Odile Cohen-Haguenauer, Florence Ledoux, Olivia Nguyen, Luca Campedel, Sylvie Giacchetti, Caroline Cuvier, Marc Espié, Luis Teixeira. Comparison of clinicopathological features and outcome of breast cancer in BRCA-mutation carriers, in patients with a family history without BRCA-mutation and in patients with sporadic disease [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 P5-03-06.