BRCA1 and breast cancer: These results indicate that BRCA1 methylation is linked to a higher risk of early-onset BC (p = 0.003, OR = 1.92, 95% CI = 1.24 to 2.99), while MGMT methylation is linked to a higher risk of late-onset BC (p = 0.0001, OR = 3.42, 95% CI = 2.23 to 5.24) compared to the control group (Table 1A,B).