Prognostic value of ERCC1 mRNA expression in non-small cell lung cancer, breast cancer, and gastric cancer in patients from Southern China.

Background: Excision repair cross complementation group 1 (ERCC1) is a nucleotide excision repair pathway gene which provides protection against platinum-based chemotherapy-induced DNA damage.
Methods: ERCC1 mRNA expression was quantified by quantitative real-time reverse-transcription PCR in paraffin-embedded non-small cell lung cancer (NSCLC; n = 357), gastric cancer (n = 106), and breast cancer (n = 363) tissues. Survival curves were generated by Kaplan-Meier analysis; Cox proportional multivariate regression analysis was applied.
Results: ERCC1 mRNA expression was significantly higher in breast cancer than gastric cancer or NSCLC (both P < 0.0001), but not significantly different in NSCLC and gastric cancer (P = 0.119). In NSCLC, the low ERCC1 group had significantly longer disease free survival (DFS) than the high ERCC1 group (29.1 vs. 21.0 months, P < 0.0001); in the surgery alone and postoperative platinum-containing chemotherapy subgroups, DFS was significantly longer for the low ERCC1 groups than high ERCC1 groups (30.2 vs. 25.1 months, P = 0.018; 27.0 vs. 19.4 months, P < 0.0001, respectively). In gastric cancer patients receiving surgery alone, the low ERCC1 group had significantly longer overall survival than the high ERCC1 group (47.54 vs. 27.47 months, P = 0.018).
Conclusions: High ERCC1 mRNA expression of the NSCLC tumor tissues was associated with poor disease-free survival (DFS), in both the surgery alone and postoperative platinum-containing chemotherapy subgroups. Meanwhile, low ERCC1 mRNA expression had significantly longer overall survival in gastric cancer patients receiving surgery alone. Therefore, ERCC1 expression was a prognostic factor and predictive marker in NSCLC, and gastric cancer after surgery alone, but was not a prognostic factor in breast cancer.