Expression of ERCC1 and class III β-tubulin in non-small cell lung cancer patients treated with carboplatin and paclitaxel

Abstract

The combination of carboplatin and paclitaxel is the most commonly used regimen for the treatment of advanced non-small cell lung cancer (NSCLC) patients. The expression of excision repair cross-complementation group 1 (ERCC1) is reported to be correlated with resistance to platinum-based drugs. Class III β-tubulin is reported to be correlated with resistance to taxanes. We evaluated whether ERCC1 and class III β-tubulin expression could predict progression-free and/or overall survival in relapsed NSCLC patients treated with carboplatin and paclitaxel. Immunohistochemistry was used to examine the expression of these two proteins in resected lung tumor samples obtained from 45 patients treated with carboplatin and paclitaxel against recurrent tumors after curative resection. Immunostaining for ERCC1 and class III β-tubulin was positive in 20 and 16 patients, respectively. Patients negative for ERCC1 had a significantly longer median progression-free (44 weeks vs. 28 weeks, P = 0.046) and overall (102 weeks vs. 56 weeks, P = 0.010) survival than those positive for ERCC1. Patients negative for class III β-tubulin expression had a significantly longer median progression-free (40 weeks vs. 35 weeks, P = 0.031), but not overall (78 weeks vs. 57 weeks, P = 0.087), survival than those positive for class III β-tubulin expression. In particular, patients negative for both ERCC1 and class III β-tubulin had significantly longer progression-free ( P = 0.036) and overall survival ( P = 0.015), compared with those positive for ERCC1 and/or class III β-tubulin. In multivariate analysis, negative class III β-tubulin expression (hazard ratio = 1.912, P = 0.048) was significantly favorable factor for progression-free survival, and negative ERCC1 expression (hazard ratio = 2.580, P = 0.014) and better performance status (hazard ratio = 3.287, P = 0.007) were significantly favorable factors for overall survival. This retrospective study indicates that immunostaining for ERCC1 and class III β-tubulin may be useful for predicting survival in NSCLC patients receiving carboplatin and paclitaxel against recurrent tumors after curative resection and can provide information critical for planning personalized chemotherapy.