Asthma and Risk of Death from Lung Cancer: NHANES II Mortality Study

Objective. Although smoking is the most important risk factor for lung cancer, nearly 10% of lung cancer is not attributable to smoking. Insights into risk factors for lung cancer other than smoking will become increasingly important, given decreasing trends in the prevalence of smoking. Prior research suggests asthma may increase the risk of lung cancer, particularly among nonsmokers. Methods. We used Cox regression analyses of data from a nationally representative sample of 9087 adults aged 30–75 years included in the NHANES II Mortality Study (1976–1992) to estimate the relative risk (RR) of death from lung cancer associated with self-reported asthma, independent of smoking. Results. Age-adjusted prevalence of smoking was 36.0%, and the age-adjusted prevalence of asthma was 6.1% (6.2% among nonsmokers) at baseline. During approximately 17 years of follow-up, 196 adults died of lung cancer (ICD-9 160–165). Among 6144 nonsmokers, the RR of lung cancer death comparing adults with asthma to those without w...