Positive expression of ERCC1 predicts a poorer platinum-based treatment outcome in Chinese patients with advanced non-small-cell lung cancer.

The goal of this study is to determine role of excision repair cross-complementing group 1 gene (ERCC1) and ribonucleotide reductase subunit M1 (RRM1) expression in predicting response and survival in Chinese patients with advanced stage non-small cell lung cancer (NSCLC) treated with platinum-based chemotherapy. Formalin-fixed, paraffin-embedded biopsy tissues were retrospectively obtained from 124 advanced NSCLC patients. Protein expression levels of ERCC1 and RRM1 were determined by immunohistochemistry (IHC). Associations between expression of ERCC1 and RRM1 and clinic-pathologic parameters were analyzed. The study shows that ERCC1 and RRM1 expression was detected in 43 (35%) and 50 (40%) of the 124 tumor samples, respectively. Expression of ERCC1 and RRM1 was negatively associated with tumor response. Fifty-four percent patients whose tumors did not express ERCC1 had partial response (PR) compared to 33% whose tumors expressed the protein (P = 0.022). Similarly, 54% patients whose tumor did not express RRM1 had PR compared to 36% whose tumors expression the protein (P = 0.042). Further, patients whose tumors lacked of ERCC1 but not RRM1 expression had a longer median survival time than those tumors expressed ERCC1 (13.4 months versus 9.1 months; P = 0.006), which is independent of other prognostic factors (P = 0.0066). In conclusion, tumor ERCC1 expression is associated with tumor response and patients' survival in Chinese advanced NSCLC patients treated with platinum-based regimen and may serve as a biomarker in predicting tumor response and clinical outcome in the patient population.