Risk of subsequent primary neoplasms developing in lung cancer patients with prior malignancies

Background: This study was performed to test the hypothesis that a history of other primary neoplasms before a lung cancer diagnosis increases the risk of subsequent malignancy. Methods: Of 8363 lung cancer patients seen from 1978 to 2002, 881 (11%) had at least 1 previous nonlung primary malignancy. Charts were analyzed for the occurrence of subsequent malignancies. Results: Lung cancer diagnosis in 881 patients consisted of 75% non-small cell, 12% small cell, and 13% other histologies. The median age was 66 years, with 56% male, 76% white, and 86% smokers. Of the 881 patients, 92% had no subsequent cancer (group 1), and 8% went on to experience the development of a new primary neoplasm (including lung) after their lung cancer (group 2). After adequate follow-up, the cumulative probability of developing a subsequent cancer did not differ markedly between those with and without a prior non-lung cancer diagnosis at 2 years (12% vs 10%) or 5 years (16% vs 15%). Group 1 patients had a significantly lower 1- and 5-year survival than group 2 patients (59% vs 48% and 29% vs 17%, respectively; P = .008). Although multivariate analysis suggested that stage, history of tobacco-associated neoplasm, and history of definitive surgical resection were important determinants in predicting long-term survival, a prior malignancy was not an independent risk factor in the development of subsequent malignancy. Conclusions: The risk of developing a subsequent malignancy is very high in lung cancer patients with prior primary malignancies, but it is not markedly different from the risks experienced by patients with no prior malignancies.