BACKGROUND In Cancer and Leukemia Group B 39801, we evaluated whether induction chemotherapy before concurrent chemoradiotherapy would result in improved survival and demonstrated no significant benefit from the addition of induction chemotherapy. The primary objective of this analysis was to dichotomize patients into prognostic groups using factors predictive of survival and to investigate whether induction chemotherapy was beneficial in either prognostic group. PATIENTS AND METHODS A Cox proportional hazard model was used to assess the impact on survival of the following factors: (>or=70 versus <70 years), gender, race, stage (IIIB versus IIIA), hemoglobin (hgb) (<13 versus >or=13 g/dl), performance status (PS) (1 versus 0), weight loss (>or=5% versus <5%), treatment arm, and the interaction between weight loss and hgb. RESULTS Factors predictive of decreased survival were weight loss >or=5%, age >or=70 years, PS of 1, and hgb <13 g/dl (p < 0.05). Patients were classified as having >or=2 poor prognostic factors (n = 165) or <or=1 factor (n = 166). The hazard ratio (HR) for overall survival for the patients with >or=2 versus patients with <or=1 was 1.88 [95% confidence interval (CI), 1.49-2.37; p = <0.0001]; median survival times observed were 9 (95% CI, 8-11) and 18 (95% CI, 16-24) months, respectively. There was no significant difference in survival between treatment arms in patients with >or=2 factors (HR = 0.86, 95% CI, 0.63-1.17; p = 0.34) or <or=1 factor (HR = 0.97, 95% CI, 0.70-1.35; p = 0.87). CONCLUSIONS There is no evidence that induction chemotherapy is beneficial in either prognostic group.