DOES RESPONSE TO INDUCTION CHEMOTHERAPY PREDICT SURVIVAL FOR LOCALLY ADVANCED NON-SMALL-CELL LUNG CANCER? SECONDARY ANALYSIS OF RTOG 8804/8808

Purpose: Induction chemotherapy (ICT) improves survival compared with radiotherapy (RT) alone in locally advanced non-small-cell lung cancer (LANSCLC) patients with good prognostic factors. Concurrent chemoradiotherapy (CCRT) is superior to ICT followed by RT. The question arises whether ICT response predicts the outcome of patients subsequently treated with CCRT or RT. Methods and Materials: Between 1988 and 1992,194 LANSCLC patients were treated prospectively with ICT (two cycles of vinblastine and cisplatin) and then CCRT (cisplatin plus 63 Gy for 7 weeks) in the Radiation Therapy Oncology Group 8804 trial (n = 30) or ICT and then RT (60 Gy/6 wk) on Radiation Therapy Oncology Group 8808 trial (it = 164). Of the 194 patients, 183 were evaluable and 141 had undergone a postinduction assessment. The overall survival (OS) of those with complete remission (CR) or partial remission (PR) was compared with that of patients with stable disease (SD) or progressive disease (PD) after ICT. Results: Of the 141 patients, 6,30,99, and 6 had CR, PR, SD, and PD, respectively. The log-rank test showed a significant difference (p<0.0001) in OS when the response groups were compared (CR/PR vs. SD/PD). On univariate and multivariate analyses, a trend was seen toward a response to ICT with OS (p = 0.097 and p = 0.06, respectively). A squamous histologic type was associated with worse OS on univariate and multivariate analyses (p = 0.031 and p = 0.018, respectively). SD/PD plus a squamous histologic type had a hazard ratio of 2.25 vs. CR/PR plus a nonsquamous histologic type (p = 0.007) on covariate analysis. Conclusion: The response to ICT was associated with a significant survival difference when the response groups were compared. A response to ICT showed a trend toward, but was not predictive of, improved OS in LANSCLC patients. Patients with SD/PD after ICT and a squamous histologic type had the poorest OS. These data suggest that patients with squamous LANSCLC might benefit from immediate RT or CCRT. (C) 2010 Elsevier Inc.