Narod et al. (2002) revealed that among BRCA1-mutation carriers, the risk of developing breast cancer was increased; however, this risk was not seen in BRCA2 carriers. In a case-controlled study by Lee et al. (2008), the use of oral contraceptives in BRCA-mutation carriers was not associated with an increased risk of breast cancer. This evidence concerns the gene BRCA1 and breast cancer.