To determine if the clinicopathologic features and survival of lung cancer patients < 50 years of age differ from those of older patients. Retrospective review of patients with primary bronchogenic carcinoma diagnosed at a single, multidisciplinary cancer center. A National Cancer Institute-designated comprehensive cancer center in urban Detroit, MI. All patients with primary bronchogenic carcinoma evaluated in the Multidisciplinary Lung Cancer Clinic at the Barbara Ann Karmanos Cancer Institute between 1990 and 1993. Of 1,012 patients with lung cancer, 126 (12.5%) were < 50 years old at diagnosis, with a median age of 44 years. The median age of the 886 patients > or = 50 years of age was 65 years. The gender (p = 0.08) and racial (p = 0.12) characteristics of the younger and older patient groups were not significantly different. More than 90% of patients in both groups were smokers. The incidence of adenocarcinoma was significantly higher in younger patients (48.4% vs 36.0%, p < 0.001), and early-stage disease was less frequently diagnosed in younger patients (4.8% vs 19.7%, p < 0.001). Younger patients were more likely than older patients to undergo treatment, including surgery and combined-modality therapy (p < 0.001). Median survival was 13 months in younger and 9 months in older patients, while overall survival was similar in younger and older patients (p = 0.13). Although younger patients with lung cancer present with more advanced-stage disease, their overall survival is similar to that of older patients, suggesting that lung cancer is not an inherently more aggressive disease in patients < 50 years of age.