BRCA1 and breast cancer: In contrast, a recent pooled analysis of data from three large cohorts found that oral contraceptive use was not associated with breast cancer risk in the prospective analysis of BRCA1 mutation carriers (HR = 1.08; 95% CI 0.75–1.56), although a moderately increased risk was observed in the left-truncated retrospective analysis (HR = 1.26; 95% CI 1.06–1.51) [72].