After stratified by sample type, we found that aberrant methylation of GSTP1 was correlated with the risk of breast cancer detected in tissue (OR = 10.32, 95 % CI = 5.97–17.85) as well as blood samples (OR = 4.02, 95 % CI = 1.12–14.38). The gene discussed is GSTP1; the disease is breast carcinoma.