BRCA1 and breast cancer: Unlike the result for BRCA1 promoter methylation, this result shows that there is a statistically significant relationship between constitutive MGMT promoter methylation and overall breast cancer incidence (p = 0.0003, OR = 1.9, 95% CI = 1.36 to 2.64), and there is a significant difference between the mean age of the two groups (Figure 1A).