Expression changes and significance of ERCC1 in non-small-cell lung cancer tissues

Objective To observe the expression changes of excision repair cross-complementation group 1( ERCC1)in human non-small-cell lung carcinoma( NSCLC) and to investigate the significance. Methods We analyzed 212 patients with NSCLC who underwent post-operative adjuvant platinum chemotherapy. The expression of ERCC1 mRNA and protein was examined by RT-PCR and immunohistochemistry( IHC). The relationship of ERCC1 with disease-free survival( DFS) and overall survival( OS) was analyzed. Results In 212 patients,79 cases( 37.26%) of patients showed low expression of ERCC1 mRNA,133 cases( 62. 74%) showed high expression; 70 cases( 33. 02%) showed low expression of ERCC1 protein and 142 cases( 66. 98%) with high expression of ERCC1 protein. The expression level of ERCC1 mRNA was related with clinical stage( P 0. 01),pathological type( P 0. 01),degree of differentiation( P 0. 05) and lymph node metastasis( P 0. 01); the expression level of ERCC1 protein was related with clinical stage( P 0. 05),pathological type( P 0. 05) and lymph node metastasis( P 0. 05). The median disease-free survival( DFS) of NSCLC patients with low expression of ERCC1 mRNA was significantly prolonged as compared with high expression patients( P 0. 01),but there was no significant difference between the DFS of low ERCC1 protein expression and high ERCC1 protein expression( P 0. 05). Multivariate Cox regression analysis showed that only clinical TNM stage was the independent prognostic factor for DFS. The expression of ERCC1 mRNA was negatively correlated with the expression of ERCC1 protein( r=- 0. 230,P 0. 01). Conclusions In NSCLC patients undergoing post-operative adjuvant platinum chemotherapy,the ones with low expression of ERCC1 have a longer DFS than those with high expression of ERCC1 and benefit from the cisplatin chemotherapy. The expression of ERCC1 mRNA is more suitable than the expression of ERCC1 protein as a prognostic factor and predictive marker for cisplatin-based chemotherapy in NSCLC patients.