DNA repair enzymes O6-methylguanine-DNA methytransferase and X-ray repair cross complementing 1 and the clinical prognostic factors in breast cancer

Objective To investigate the expression of O6-methylguanine-DNA methytransferase (MGMT) and X-ray repair cross complementing 1 (XRCC1) in breast cancer, and their relationship with clinical prognostic factors. Methods Immunohistochemistry (S-P) was performed for MGMT and XRCC1 on 110 specimens of breast cancer, 19 specimens of fibroadenoma and 11 specimens of normal breast tissues. Results The positive expression rate of MGMT was 71.8%, which had a correlation with pathological classification, pathological grades of infitrating ductal carcinoma ( IDG), axillas lymph nodes metastasis, and expression of ER ( P ＜ 0.05). The positive expression rate of XRCC1 was 30.9%, which had a correlation with the tumor size and the pathological grades of IDG. The expression rate of MGMT had a positive correlation with XRCC1 (P ＜0.05). The survival analysis showed that MGMT and XRCC1 may be considered a independent maker in breast cancer ( P ＜ 0.05 ). Conclusion MGMT and XRCC1 were important pathological signs to evaluate the malignancy degree and prognosis of the breast cancer. These markers play an important role in working out the treatment prescription for breast cancer patients. Key words: Breast cancer;  Prognosis;  Immunohistochemistry