Studies have also demonstrated that BRCA1 promoter methylation is a possible marker of poor disease outcome, as it is associated with reduced disease-free survival (DFS), overall survival (OS) and an increased risk of breast cancer-specific mortality, and also seems to be associated with increased sensitivity to adjuvant chemotherapy [13, 34, 35, 37, 38]. This evidence concerns the gene BRCA1 and breast carcinoma.