Abstract:

Objective    To explore the relationship of expressions of ribonucleotide reductase M1 RRM1 and excision repair cross complementation 1(ERCC1) proteins with response and prognosis of patients with advanced(IIIB-IV) non-small cell lung cancer (NSCLC) receiving cisplatin combined with gemcitabine (GP) chemotherapy. Methods     Clinical pathological data from 47 advanced NSCLC patients who received GP chemotherapy were retrospectively analyzed, and their tumor samples were collected.  Expressions of RRM1 and ERCC1 proteins in tumor samples were detected by the immunohistochemical method. The therapeutic effect and survival time were analyzed. Results     RRM1 and ERCC1 positive rates were 46.81%(22/47)and 42.55%(20/47)， respectively. There was no correlation of RRM1 and ERCC1 expressions with gender，age, PS scores, pathological type，TNM stage and smoking. The overall response rate was 36.17%(17/47). Response rates were 18.18%(4/22) and 52.00%(13/25) respectively in patients with high and low RRM1 expressions(P=0.016), while they were 20.00%(4/20) and 48.15%(13/27)in patients with high and low ERCC1 expressions，  respectively(P=0.047). Low expression of RRM1 or ERCC1 protein was correlated with longer median overall survival (14.1 months， 14.1 months), while the median overall survival of high expression ofRRM1 or ERCC1 protein was 6.8months and 7.1months, respectively(P=0.008，0.017). Patients with low expressions of both RRM1 and ERCC1 proteins had longer median overall survival(14.8 months) than those with high expressions of RRM1 and/or ERCC1(7.6months)(P=0.012). Cox regression analysis revealed that the TNM stage was an independent prognostic factor. Conclusions     Expressions of RRM1 and ERCC1 proteins have a negative correction with the response to GP chemotherapy and prognosis. Advanced NSCLC patients with low expression of RRM1 or ERCC1 may get more benefits from GP chemotherapy.

Key words: Lung neoplasms；  Immunohistochemistry； Genes；  Cisplatin/gemcitabine