ERCC1 expression as a prognostic marker in N2(+) nonsmall-cell lung cancer patients treated with platinum-based neoadjuvant concurrent chemoradiotherapy

BACKGROUND. Excision repair cross-complementation Group 1 (ERCC1) overexpression is associated with resistance to cisplatin-based chemotherapy in patients with nonsmall-cell lung cancer (NSCLC). A preliminary study also suggested that ERCC1 expression is associated with radioresistance in lung cancer cells. The aim of this study was to evaluate the clinical implications of ERCC1 expression in stage IIIA N2-positive NSCLC patients treated with platinum-based neoadjuvant concurrent chemoradiotherapy (CCRT) followed by surgery. METHODS. Sixty-eight patients with mediastinoscopy-proven N2-positive NSCLC were enrolled between August 1997 and September 2003. ERCC1 expression was assessed by immunohistochemistry from pretreatment mediastinoscopic biopsy specimens. RESULTS. ERCC1 expression was positive in 31 of 68 specimens (46 h). Among 14 patients who obtained pathologic complete response, 6 were positive for ERCC1 expression and 8 were negative (P = .818). On univariate analysis, with median follow-up of 61.8 months (range, 34.3-108.8 months), progression-free survival was 15.9 months for ERCC1-positive and 29.5 months for ERCC1-negative patients (P = .062), and there was a statistically significant difference in overall survival between ERCC1-negative tumors and ERCC1-positive tumors (89.2 vs 26.0 months, P = .014). On multivariate analysis, ERCC1 negativity (P = .041) and achieving mediastinal nodal clearance (downstage to pathological N0 or N1) after neoadjuvant CCRT followed by surgery (P =.005) were significant independent prognostic factors for the prolongation of survival. CONCLUSIONS. These results suggest that N2-positive NSCLC patients with ERCC1 negative tumors show a survival benefit from neoadjuvant CCRT with a platinum-containing regimen.