Purpose: Compared to European Americans (EAs), African Americans (AAs) suffer a disproportionate share of the lung cancer mortality burden. To investigate whether this disparity in lung cancer mortality is due to differential racial risks related to socioeconomic status (education, occupation), body mass index (BMI), hypertension, or cigarette smoking, we compared associations between these factors and lung cancer mortality by race in a biracial prospective cohort study.
Methods: The Charleston (South Carolina) Heart Study (N = 2,054) was established in 1960; 40% of the study participants are AAs. The participants have been followed up for mortality for 40 years. Using Cox proportional hazards models, we investigated whether there were racial differences in the associations between the study factors and lung cancer mortality.
Results: Cigarette smoking was the strongest lung cancer risk factor in both races. The association between cigarette smoking and lung cancer mortality was stronger in EAs than AAs (hazards ratio [HR] 26.1 vs. 7.6). In both races, men were at significantly greater risk than women and BMI was significantly inversely associated with lung cancer mortality.
Conclusions: The evidence from the present study does not yield strong clues for the excess lung cancer mortality in AAs. Our results do not support the hypothesis that differential susceptibility to cigarette smoking is a major contributor to the racial disparity in lung cancer. This suggests we must expand our scope of inquiry beyond the factors included in the present study to fully understand why lung cancer mortality rates are greater in AAs than EAs.