Epigenetic Risk Factors in Women with Breast Cancer: A Family Case-Control Study

Purpose: The purpose is to disseminate the current scientific evidence, including meta-analyses and a pilot prospective family-based case-control study on genome health on epigenetic risk factors for breast cancer.

Breast cancer is the most common malignancy and the second leading cause of cancer death among women worldwide. Methylenetetrahydrofolate reductase (MTHFR) is critical for methylation pathways for deoxyribonucleic acid (DNA) repair and normal cellular development. Methylation pathways are affected by health behaviors such as folate intake, alcohol consumption, and tobacco smoking. 

 Methods: Meta-analyses and a prospective pilot study on the associations of MTHFR gene variations, and health behaviors with breast cancer.

 Results:  Preliminary meta-analyses results included 55 studies for a total of 22,077 breast cancer cases and 25,419 controls including 27 studies with Whites, 21 studies with Asians, and 7 studies with mixed Euramericans. From the selected studies with MTHFR gene counts, there were 12 studies with folate intake levels for 8,032 cases and 10,482 controls; 5 studies with alcohol consumption for 3,068 cases and 5,157 controls; and 5 studies with tobacco smoking status for 909 cases and 1,233 controls. MTHFR C677T was associated with increased risk of breast cancer (P < 0.005). The results also suggested that low folate intake, heavy alcohol consumption, and tobacco smoking contributed to increased risks for breast cancer. Preliminary results of the prospective pilot study conducted in southern California will be presented. 

 Conclusion: The results of this study can be translated into individual differences in gene variations and personalized behavioral interventions for cancer prevention. In addition, it has implications for the role of the nurses as advocates for their clients through knowledge interface from epigenetic advances to efficient health promotion in the clinical and community settings.