Authors: Ghimire S, Shrestha N, BK Baral
The literature linking breast cancer with oral contraceptives and BRCA mutation as possible risk factors is equivocal. Hence, to account for these conflicting results in the existing literature and to observe the net effect, this meta-analysis aims to investigate whether oral contraceptives are a risk factor for developing breast cancer in breast cancer (BRCA) gene carrier female in the 30-60 years age group. Method: Systematic review of the literature, both published and unpublished, and meta-analysis of relevant data. Results: Meta-analysis of data from five relevant studies, with a total of 6682 BRCA carriers (3,269 BRCA1 carriers and 791 BRCA2 carriers), revealed that use of oral contraceptives is associated with increased risk of breast cancer among BRCA mutation carriers (OR=2.267; 95 % CI= 1.311, 3.919). When the same risk was stratified by mutation type, both BRCA1 and BRCA2 were at increased risk. However, BRCA2 carriers (OR= 3.060; 95% CI=0.951, 9.848) were found to be at elevated risk compared to BRCA1 carriers (OR= 2.347; 95% CI=0.939, 5.865). Conclusions: This meta-analytical finding suggests that oral contraceptives are a risk factor for developing breast cancer in breast cancer (BRCA) gene carrier females.
Key words: Oral contraceptives, Breast cancer, BRCA gene, Familial breast cancer and hereditary breast cancer