Abstract: AIM: To evaluate the predictive value of gene expression of ribonucleotide reductase M1 (RRM1) and excision repair cross-complementation 1( ERCCl ) in peripheral blood from Chinese patients with non-small-cell lung cancer (NSCLC) treated with gemcitabine plus platinum.METHODS: SYBR real-time PCR was used to determine the tumor tissue and peripheral blood RRM1 and ERCC1 mRNA expression levels in NSCLC patients. The χ² test was used to analyze categorical variables and Spearman rank correlation analysis was used to analyze continuous variables. Kaplan-Meier survival curves and the log-rank test were used for the comparison of overall survival rates.RESULTS: In the present study, 34 Chinese patients with histologically confirmed stages IIIB and IV NSCLC were recruited; the tumor tissue and peripheral blood gene expression levels were measured in 22 patients. Linear correlations were observed between peripheral blood and tumor tissue expression levels for RRM1 (R²=0.045, P=0.048), while no correlation was detected for ERCC1 (R²=0.016, P=0.251). Subjects with low peripheral blood RRM1 expression survived longer than those with high RRM1 expression (16.0 vs12.5 months, log-rank 3.980, P=0.046). The expression of ERCC1 showed no obvious differences between the two groups.CONCLUSION: The study demonstrates increased survival and superior efficacy of gemcitabine and cisplatin combination chemotherapy in the treatment of NSCLC patients with low peripheral blood RRM1 expression. The results contribute to the selection of patients who are most suitable for treatment with gemcitabine and cisplatin combination chemotherapy.

Key words: Non-small cell lung, Gemcitabine, RRM1, ERCC1