OT2-04-03: Uptake of a Randomized Breast Cancer Prevention Trial Comparing Letrozole to Placebo in BRCA1/2 Mutations Carriers: The FNCLCC ONCO-03/LIBER Trial.

Background: Women with germline BRCA1or BRCA2 (BRCA1/2) mutations are an extreme risk population for developing breast cancer, with a life-time risk of 56–80%. Prophylactic mastectomy provides a valid option to reduce such risk, but it considerably affects the quality of life. Medical prevention by aromatase inhibitor that has been recently shown to have preventive effect may thus be an alternative. LIBER is an ongoing, double-blind, randomized phase III trial to evaluate the efficacy of five-years letrozole versus placebo to decrease breast cancer incidence in post-menopausal BRCA1/2 mutation carriers (NCT00673335). We present data on the uptake of this trial. Methods: To evaluate theoretical feasibility, we compared inclusion criteria of women in the LIBER trial (n=113) to characteristics of women entered in the prospective ongoing national GENEPSO cohort (n=1505). Uptake was evaluated through a survey sent to all active centres, with responses obtained from 17 of the 20 (85%) centres. Results: According to characteristics of the women included in GENEPSO cohort (n=1505) and the survey, approximately one third of BRCA1/2 mutation carriers are eligible for this study. From november 2009 to may 2010, 534 women eligible from chart review have been informed by mail of the trial and were invited to an oral information by participating centres. Of them, 44% of women came to the dedicated medical visit. Uptake of drug prevention trial was 32 % of orally informed women and 15 % of overall eligible women. Main reasons of refusal were: potential side effects, probability to receive the placebo and lack of support from the women9s physicians. Prior prophylactic oophorectomy and history ***of previous unilateral breast cancer were more frequent in women enrolled in the ONCO-03/LIBER trial than in the French cohort (93% versus 60% and 50 % versus 39 %, respectively), suggesting a higher motivation for medical prevention in these subgroups of patients. Conclusion: One third of women with a BRCA1/2 mutation are eligible to the ONCO-03/LIBER prevention trial. 32 % of orally informed women and, only 15% of overall eligible women entered the trial. To reach accrual objective (n=308), a greater information of the trial should be offered to women with BRCA1/2 mutation and the trial has been proposed to other countries. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT2-04-03.