SHARE: a French multicenter phase III trial comparing accelerated partial irradiation versus standard or hypofractionated whole breast irradiation in breast cancer patients at low risk of local recurrence.

The standard treatment for breast cancer patients at low risk of recurrence is based on conservative surgery followed by radiation therapy delivered to the whole breast. The accelerated partial breast irradiation (APBI) concept, developed more than 15 years ago, could be an option in selected patients. However, the ideal patient profile for APBI is still not clearly identified. Recent reports from the American Society for Radiation Oncology (ASTRO) and the Groupe Européen de Curiethérapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) have suggested selection criteria for "suitable patients" who could receive APBI outside of clinical trials. Currently, there are 6 ongoing phase III trials. All are characterized by a significant heterogeneity regarding inclusion criteria and stratification factors. The French UNICANCER trial (SHARE; ClinicalTrials.gov identifier NCT01247233) will randomize 2,800 patients in 3 arms: APBI (1 week) using 3-dimensional (3D) conformal radiotherapy, standard radiotherapy (6.5 weeks), and hypofractionated radiotherapy (3 weeks). In this article, we review the reported retrospective studies as well as older randomized trials. We will also describe the differences between the 6 ongoing phase III trials and the particularities of the French SHARE trial.

Uptake of a randomized breast cancer prevention trial comparing letrozole to placebo in BRCA1/2 mutations carriers: the LIBER trial.

Women with germline BRCA1 or BRCA2 (BRCA1/2) mutations are considered as an extreme risk population for developing breast cancer. Prophylactic mastectomy provides a valid option to reduce such risk, impacting however, the quality of life. Medical prevention by aromatase inhibitor that has also recently shown to have preventive effect may thus be considered as an alternative. LIBER is an ongoing double-blind, randomized phase III trial to evaluate the efficacy of 5-year 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. We compared characteristics of women in the LIBER trial (n = 113) to those of women enrolled in the prospective ongoing national GENEPSO cohort (n = 1,505). Uptake was evaluated through a survey sent to all active centres, with responses obtained from 17 to the 20 (85%) centres. According to the characteristics of the women enrolled in the GENEPSO cohort and the survey, approximately one-third of BRCA1/2 mutation carriers were eligible for the trial. Five hundred and thirty-four women eligible from chart review have been informed by mail about the prevention trial and were invited to an oral information by participating centres. Forty-four percentage of them came to the dedicated medical visit. Uptake of drug prevention trial was 32% among women informed orally and 15% of all the eligible women. The main reasons of refusal were: potential side effects, probability to receive the placebo and lack of support from their physicians. Additionally, we noticed that prior prophylactic oophorectomy and previous unilateral breast cancer were more frequent in women enrolled in the LIBER trial than in the French cohort (93% vs. 60% and 50% vs. 39%, respectively). Based on an overall 15% uptake among all eligible subjects, greater and wider information of the trial should be offered to women with BRCA1/2 mutation to improve recruitment. Women with previous unilateral breast cancer or prior prophylactic oophorectomy are more likely to enter a medical prevention trial.