Lung cancer in nonsmokers seen as distinct disease entity

There are demographic and survival differences between cigarette smokers and never-smokers who develop lung cancer, researchers report. They say the findings indicate that lung cancer in nonsmokers is a specific disease, and this has implications for research and clinical trials.

Dr. George R. Simon and colleagues from the H. Lee Moffitt Cancer Center and Research Institute in Tampa, Florida, analyzed patient characteristics and survival in 132 never-smokers and 522 current smokers diagnosed with primary lung adenocarcinoma. They observed that never-smokers were generally older at diagnosis (63.5 years vs 59.4 years) and more often female (78% vs 54%). Also, never-smokers had better overall survival than current smokers, with survival estimates at 5 years of 23% versus 16%. In multivariate analyses, smoking was an “independent negative prognostic factor,” the investigators report in the August issue of Chest. Commenting on these findings, Dr. Simon told Reuters Health: “Lung cancers in smokers arise secondary to the carcinogenic properties of chronic tobacco use. Lung cancers in never-smokers arise without the carcinogenic properties of tobacco and therefore have a distinct underlying molecular biology that drives the formation of this cancer and consequently have a distinct tumor behavior and patient survival.” Lung cancer in never-smokers “is a different disease in itself, with its own unique biology, behavior characteristics, and survival,” Dr. Simon concluded. “Therefore, we assert that laboratory and clinical investigations be specifically designed to further study this distinct disease entity.” Dr. Peter J. Mazzone and two colleagues from The Cleveland Clinic Foundation in Ohio concur, noting in an editorial in Chest that this study “further highlights the importance of stratification of patients for smoking history in future clinical trials.” (Source: Chest 2004;126:326-328,347-351: Reuters Health News: Megan Rauscher: Oncolink: August 2004.)