Lifestyle and environmental factors in women carrying BRCA pathogenic variants with and without cancer

Background: In the development of breast cancer (BC) and ovarian cancer (OC) there may be an influence of lifestyle and environmental factors. This influence could be relevant also in patients with genetic predisposition such as in carriers of germline pathogenic variants (VP) in the BRCA genes (gBRCA). However, this issue has been addressed in only a few studies so far.\r\n\r\nMethods: In this retrospective, multicenter case-control study we enrolled subjects with a VP gBRCA and divided into 2 groups: Group 1, patients with BC and/or OC, and Group 2, subjects without cancer. We compared these groups regarding demographic data as age, body mass index (BMI); smoking habits (SH); Estroprogestinic use (EP); Mediterranean diet and physical activity. Multivariable analyses were used to identify predisposing factors. All evaluations were two-tailed and considered significant if p-value < 0.05.\r\n\r\nResults: We enrolled 281 subjects, 135 (79.4%) with BC, 32 (18.8%) with OC, 3 (1.8%) with both and 111 unaffected women (39.5%). Independent risk factors associated with cancer were: age (p < .0001); BMI (p = .007); family history (FHx)(p = .002); occupation (p = .003); SH (p = .012), number of cigarettes smoked (p = .016), pack/year index (p = .022); EP use (p = .032) and years of EP use (p = .029). At multivariate analysis, age (OR 1.062; p < .0001), FHx (OR 0.129; p = .001), number of cigarettes smoked (p = .014) and estroprogestinic use (OR 2.009; p = .025) were significant risk factors associated with cancer development.\r\n\r\nConclusions: In the development of BC and OC, lifestyle and environmental factors seem to play a significant role in the presence of genetic predisposition associated with BRCA 1 and BRCA 2 genes mutation.\r\n\r\nKeywords: BRCA 1; BRCA 2; Breast Cancer; Environmental Factors; Lifestyle; Ovarian Cancer; Pathological Variants.