Abstract
BACKGROUND AND OBJECTIVE: It has been proven that ribonucleotide reductase M1 (RRM1) expression level was closely related to gemcitabine drug-resistance to tumor cells. The aim of this study is to explore the relations between RRM1 protein expression levels and effects of gemcitabine and cisplatin chemotherapy in advanced non-small cell lung cancer (NSCLC) patients. METHODS: The expressions of RRM1 in 75 advanced NSCLC tissues were qualitatively detected by immunohistochemical methods. Seventy-five patients had received gemcitabine and cisplatin (GP) chemotherapy regimen. General characteristics of patients, response to treatment, efficacy evaluation and survival time were retrospectively investigated. Differences between the groups were statistically analysed by chi-square test. Survival differences were analysed by temporal inspection and Kaplan-Meier survival curves. RESULTS: RRM1 protein expression rate was 38.7%. RRM1 protein expression had no obvious relationship with gender, age, smoking status, and the clinical stages and histopathological types (P > 0.05). Response rate in RRM1 protein high expression groups (31.3%) was remarkably lower than that in low expression groups (41.3%), the difference was statistically significant (P=0.005). 1-year survival rate in RRM1 protein high expression groups (27.6%) was remarkably lower than that in low expression group (58.7%), the difference was statistically significant (P=0.009). No significant different of median survival was observed between RMM1 protein high expression group and low expression group (P >0.245). Time to progression in RRM1 protein high expression groups (3.10 months) was remarkably lower than that in low expression group (5.11 months), the difference was statistically significant (P=0.042). CONCLUSIONS: RRM1 protein expression levels are closely related to effects of gemcitabine and cisplatin chemotherapy and prognosis of advanced NSCLC patients.