OBJECTIVETo investigate the expression of RRM1 and ERCC1 genes in tumor tissues and peripheral blood lymphocytes of advanced non-small cell lung cancer (NSCLC).

METHODSTissue and peripheral blood samples were collected from 49 advanced NSCLC patients treated with gemcitabine plus carboplatin. The expressions of RRM1 and ERCC1 mRNA in tumor tissue and peripheral lymphocytes were detected by real-time fluorescent quantitative PCR. The relationship of gene expression with clinical characteristics,chemotherapy response and prognosis was analyzed.

RESULTSThe RRM1 expression in tumor tissues was positively correlated with that in peripheral blood lymphocytes,while no significant correlation was observed between ERCC1 expression in tumor tissues and that in peripheral blood (rs=0.332 and 0.258; P=0.020 and 0.073, respectively). The expression of RRM1 and ERCC1 in tumor tissues peripheral lymphocytes was synchronous (rs=0.634 and 0.351; P<0.001 and 0.013, respectively). There was no significant correlation of gene expression with gender, age, smoking status, performance status, clinical stages and histological types of patients (P>0.05). Significant difference was found in response rate to chemotherapy (P<0.05,P<0.01,P<0.05),median survival time (P<0.05,P<0.01,P<0.05) and 1-year survival rate (P<0.01,<0.05,P<0.05) between patients with low RRM1 and ERCC1 expression levels in tumor tissues or low RRM1 expression levels in peripheral blood and those with high RRM1 and ERCC1 expression levels. The patients with low ERCC1 expression levels in tumor tissues gained higher 2-year survival rate (P<0.05). There was no correlation of the expression of ERCC1 in peripheral blood with the response to chemotherapy and prognosis (P>0.05).

CONCLUSIONThe expression of RRMI and ERCC1 genes in tumor tissues and RRM1 in peripheral blood lymphocytes is closely correlated with the response to chemotherapy and prognosis of patients with advanced NSCLC treated with gemcitabine plus carboplatin.