Gene Methylation In Random Fna Samples As Biomarkers For Breast Cancer

518 Background: Current methods to determine breast cancer risk are insufficiently sensitive to select women most likely to benefit from preventive strategies. We hypothesized that candidate gene promoter hypermethylation may provide an individualized risk profile. We performed a prospective study to determine whether DNA cumulative methylation index (CMI) varies by menstrual phase or menopausal status, and to correlate CMI with established risk factors. Methods: We obtained random fine needle aspiration (rFNA) samples from healthy women age 35-60 and determined their menopausal and menstrual status, lifetime Gail risk, mammographic breast density, and cytologic atypia assessed as the Masood score. We evaluated CMI of 11 candidate genes in rFNA cells using the Quantitative Multiplex Methylation-Specific PCR (QM-MSP) technique. We used Wilcoxon test and ANOVA model to compare CMI across menopausal and menstrual (follicular, mid-cycle, luteal) categories, respectively. We used linear regression model to adj...