Prognostic Significance Of DNA Repair Genes ERCC1 And MGMT Expression In Early Stage Non-small-cell Lung Cancer

Objective:To investigate the expression status of MGMT and ERCC1 in tumor tissue of 42 NSCLC patients who received postoperative adjuvant chemotherapy with cisplatin. The aim of this study was to explore the relationship between the expression of MGMT and ERCC1 protein and clinicopathological parameters, prognosis of NSCLC.Methods:Immunohistochemical method (SP) was used to detect the expression of DNA repair protein MGMT and ERCC1 in 42 NSCLC patients. The survival of the 42 patients was followed up. We investigated the pathological and prognostic characteristics of NSCLCs that had been stratified according to protein status. Catergorical variables were comparaed using the chi-square test. The Kaplan-Meier method was used to calculate time to overall survival. Differences were assessed using log rank statistics. The prognostic value of MGMT and ERCC1 expression for NSCLCs was studied with multivariate Cox proportional hazards regression models.Results:1. MGMT positively expressed in 15 of 42 patients with NSCLC (35.7%), ERCC1 positively expressed in 19 of 42 patients with NSCLC (45.2%).2. No significant relationship was found among MGMT expression and age, gender, TNM stage, smoke history, differentiated types, histological classification. lymph node metastasis and pleural involvement.Neither do ERCC1.3. Kaplan-Meier curves showed patients with a positive MGMT expression had a significantly poorer overall survival than MGMT-negative patients (median overall survival 27 months for MGMT-positive vs.42 months for MGMT-negative,P= 0.049; log-rank test), patients with a positive ERCC1 expression had a significantly poorer overall survival than ERCC1-negative patients (median overall survival 34 months for ERCC1-positive vs.40 months for ERCC1-negative, P=0.027; log-rank test).In multivariate Cox proportional hazards regression analysis, ERCC1 expression (RR:4.476,95%CI:1.388-14.435 P=0.012) and TNM stage (RR:3.150,95%CI:1.189-8.347 P=0.021) were significant independent prognostic factors for overall survival respectively. ERCC1 expression play a very important role in pathogenesis of NSCLC and tumor progressionConclusion:The expression of MGMT and ERCC1 were more frequently found in in non-small cell lung cancer. Patients with MGMT positive expression or ERCC1 positive expression had a significantly poorer overall survival than negative expression in unvariate analysis respectively. In multivariate analysis, both ERCC1 expression and TNM-stage were found to be independent prognosis factors. The patients with ERCC1 positive expression had poor prognosis.