Survival outcomes of metastatic breast cancer patients by germline BRCA1/2 status in a large multicenter real-world database
Menée à partir de données multicentriques 2008-2016 portant sur 20 624 patientes atteintes d'un cancer du sein métastatique (durée médiane de suivi : 50,5 mois), cette étude analyse la survie globale chez les patientes porteuses d'une mutation constitutionnelle de BRCA1/2
The outcomes and best treatment strategies for germline BRCA1/2 mutation (gBRCAm) carriers with metastatic breast cancer (MBC) remain uncertain. We compared the overall survival and the first line progression free survival (PFS1) of patients with a gBRCAm identified at initiation of first-line treatment with those of BRCA wild-type (WT) and not-tested (NT) individuals in the ESME real-world database of MBC patients between 2008 and 2016 (NCT03275311). Among the 20624 eligible patients, 325 had a gBRCAm, 1138 were WT, and 19161 NT. Compared to WT, gBRCAm carriers were younger, and had more aggressive diseases. At a median follow-up of 50.5 months, median OS was 30.6 (95%CI: 21.9-34.3), 35.8 (95%CI: 32.2-37.8) and 39.3 months (95% CI: 38.3-40.3) in the gBRCAm, WT and NT subgroups, respectively. Median PFS1 was 7.9 (95%CI: 6.6-9.3), 7.8 (95%CI: 7.3-8.5) and 9.7 months (95%CI, 9.5-10.0). In the multivariable analysis conducted in the whole cohort, gBRCAm status had however no independent prognostic impact on OS and PFS1. Though, in the triple-negative subgroup, gBRCAm patients had better OS and PFS1 (HR vs WT=0.76; 95%CI: 0.60-0.97; p=0.027 and 0.69; 95% CI: 0.55-0.86; p= 0.001 respectively). In contrast, in patients with HR+/HER2 negative cancers, PFS1 appeared significantly and OS non significantly lower for gBRCAm carriers (PFS1: HR vs WT =1.23; 95%CI: 1.03-1.46; p=0.024; OS:HR=1.22, 95% CI: 0.97-1.52, p=0.089). In conclusion, gBRCA1/2 status appears to have divergent survival effects in MBC according to IHC subtype.