Prognostic value of ERCC1, RRM1, and TS proteins in patients with resected non-small cell lung cancer

Recent clinical trials showed that expression of excision repair cross-complementation group 1 (ERCC1), ribonucleotide reductase M1 (RRM1), and thymidylate synthase (TS) proteins was able to predict the effects of non-small cell lung cancer (NSCLC) to chemotherapy. However, it remains unknown whether the adjuvant chemotherapy based on expression of the three proteins has survival significance in Chinese NSCLC patients. We investigated 128 Chinese patients receiving chemotherapy after tumor resection for expression of these proteins using immunohistochemistry. Based on protein expression, patients were assigned to two groups for different adjuvant chemotherapy regimes. The disease-free survival (DFS) data were collected and analyzed using Kaplan-Meier curves and Cox models. We found that DFS of these patients with carboplatin and a third-generation agent (gemcitabine or pemetrexed) stratified by protein expression showed no statistical difference between individual treatment versus non-individuation treatment analyzed using Kaplan-Meier method (P = 0.143, median 23.9 vs. 30.8 months). Furthermore, the multivariate analysis showed that histology and tumor stages were independent predictors for DFS in these patients. The results suggest that chemotherapy based on ERCC1, RRM1, and TS expression did not have significant impact on DFS of patients with resection of NSCLC.