Purpose: Cyclooxygenase-2 (COX-2) protein expression in patients with non-small-cell lung cancer (NSCLC) may be not only a prognostic marker but also predictive for COX-2 inhibition. We hypothesized that COX-2 expression is associated with shorter survival and that celecoxib, being a potent COX-2 inhibitor, increases tumor response and survival.
Patients and methods: A phase III study was performed in patients with stage IIIb/IV NSCLC who had pathologic confirmation, no prior chemotherapy, Eastern Cooperative Oncology Group performance status of 0 to 2, and adequate organ function. Treatment consisted of docetaxel and carboplatin every 3 weeks for five cycles. Patients were randomly assigned to receive celecoxib 400 mg or placebo twice daily. COX-2 expression on tumor cells was detected by immunohistochemistry. Primary end point was overall survival (OS).
Results: From July 2003 to December 2007, 561 patients were randomly assigned. Toxicity was mild, and no increase in cardiovascular events was observed. Tumor response was 38% in the celecoxib arm and 30% in the placebo arm (P = .08). Median progression-free survival was 4.5 months (95% CI, 4.0 to 4.8) for the celecoxib arm and 4.0 months (95% CI, 3.6 to 4.9) for the placebo arm (hazard ratio [HR], 0.8; 95% CI, 0.6 to 1.1; P = .25). Median OS was 8.2 months (95% CI, 7.5 to 8.8) for both treatment arms (HR, 0.9; 95% CI, 0.6 to 1.2; P = .32). COX-2 expression did not independently predict survival. Benefit from celecoxib, restricted to patients with low COX-2 expression, was not significant when adjusted for prognostic factors.
Conclusion: In advanced NSCLC, celecoxib does not improve survival. In this study, COX-2 expression was not a prognostic biomarker and had no predictive value when celecoxib was added to chemotherapy.