Objective: To evaluate the predictive values of gene expressions of ribonucleotide reductase M1 (RRM1) and breast cancer susceptibility gene 1 (BRCA1) in peripheral blood from Chinese patients with non-small-cell lung cancer (NSCLC) treated with gemcitabine plus platinum.
Methods: Forty Chinese patients with advanced NSCLC were recruited and received gemcitabine 1 200 mg/m(2) on Days 1 and 8 plus carboplatin AUC 5 on Day 1. RRM1 and BRCA1 expression levels in peripheral blood were detected by quantitative reverse transcription-polymerase chain reaction (RT-PCR). Kaplan-Meier survival curve and log-rank test were performed to evaluate the correlation between gene expression and overall survival for these subjects.
Results: No correlation was observed between gene expression of RRM1 and that of BRCA1 (P>0.05), but there was a strong correlation between the expression of RRM1 and the response to chemotherapy (P=0.003). Subjects with low RRM1 expression levels in peripheral blood had longer survival time than those with high RRM1 expression levels (16.95 vs. 12.76 months, log-rank 3.989, P=0.046). However, no significant association between BRCA1 expression levels and survival time was found (16.80 vs. 13.77 months, log-rank 0.830, P=0.362).
Conclusions: Patients with low RRM1 expression levels in peripheral blood have a greater response to chemotherapy and longer survival time. Advanced NSCLC patients with low RRM1 expression levels may benefit from gemcitabine plus platinum therapy. RRM1 mRNA expression in peripheral blood could be used to predict the prognosis of NSCLC treated by gemcitabine and platinum.