Can harmful lifestyle, obesity and weight changes increase the risk of breast cancer in BRCA 1 and BRCA 2 mutation carriers? A Mini review

Background and aim The BRCA 1 and BRCA 2 genes are associated with an inherited susceptibility to breast cancer with a cumulative risk of 60% in BRCA 1 mutation carriers and of 30% in BRCA 2 mutation carriers. Several lifestyle factors could play a role in determining an individual’s risk of breast cancer. Obesity, changes in body size or unhealthy lifestyle habits such as smoking, alcohol consumption and physical inactivity have been evaluated as possible determinants of breast cancer risk. The aim of this study was to explore the current understanding of the role of harmful lifestyle and obesity or weight change in the development of breast cancer in female carriers of BRCA 1/2 mutations. Methods Articles were identified from MEDLINE in October 2020 utilizing related keywords; they were then read and notes, study participants, measures, data analysis and results were used to write this review. Results Studies with very large case series have been carried out but only few of them have shown consistent results. Additional research would be beneficial to better determine the actual role and impact of such factors.