Objective To investigate the hypermethylation status of glutathione transferase P1(GSTP1)and E-cadherin(ECAD),TSGs(tumor suppressor genes)in our breast cancer samples and explore their correlation with clinicopathological features of corresponding cancer patients.Methods One hundred and thirty-six IDC(invasive ductal carcinoma)patients were recruited for analysis and 16 fibroadenoma patients acted as control.DNA extraction and methylation-specific PCR(MSP)were subsequently performed preceded by pathological examination.Results The percentage of hypermethylated GSTP1 in carcinoma and fibroadenoma groups was 34.92% and 15.79% respectively and the percentage of hypermethylated ECAD in carcinomas and fibroadenomas was 18.00% and 0.00% respectively.Carcinoma had the highest percentage of c-erbB2 overexpression being 54.55% among the clinicopathological parameters.Conclusion Hypermethylation patterns are frequent in IDC and seem to relate to c-erbB2 overexpression,and such epigenetic change should not be neglected in fibroadenoma.Tumor methylation status in cancer patients can be determined at early stage and it may be a reference for better treatment planning. Objective To investigate the hypermethylation status of glutathione transferase P1 (GSTP1) and E-cadherin (ECAD), TSGs (tumor suppressor genes) in our breast cancer samples and explore their correlation with clinicopathological features of corresponding cancer patients. Methods One Hundred and Thirty- Six IDC (invasive ductal carcinoma) patients were recruited for analysis and 16 fibroadenoma patients acted as control. DNA extraction and methylation-specific PCR (MSP) were successfully performed preceded by pathological examination. Results The percentage of hypermethylated GSTP1 in carcinoma and fibroadenoma groups was 34.92% and 15.79% respectively and the percentage of hypermethylated ECAD in carcinomas and fibroadenomas was 18.00% and 0.00% respectively. Carcinoma had the highest percentage of c-erbB2 overexpression being 54.55% among the clinicopathological parameters. Conclusions Hypermethylation patterns are frequent in IDC and seem to relate to c-erbB2 overexpression, and such epigenetic change should not be neglected in fibroadenoma. Tumor methylation status in cancer patients can be determined at early stage and it may be a reference for better treatment planning.