Cigarette smoking and malignant melanoma: A case-control study

Background: Several previous studies have reported inverse associations between cigarette smoking and melanoma. Often these studies have not adjusted for ultraviolet (UV) exposure history, skin type, or number of blistering sunburns, which could confound the observed associations between cigarette smoking and melanoma. Objective: We sought to assess whether this reported inverse association persists after adjusting for UV exposure, skin type, and number of blistering sunburns. Methods: We conducted a population-based case-control study (82 patients with melanoma, 164 control subjects). Two control subjects were matched to each patient by age, sex, race, and skin type. Conditional logistic regression models were fit to assess the association between cigarette smoking history and melanoma, with additional adjustments for UV exposure and sunburns. Results: Compared with never smoking, both former (odds ratio 0.43, 95% confidence interval 0.18-1.04) and current (odds ratio 0.65, 95% confidence interval 0.19-2.24) smoking were inversely associated with melanoma, but the associations were not statistically significant. Limitations: The number of cutaneous nevi was not assessed in this study. In addition, the relatively small number of patients limits the statistical precision of the observed associations. Conclusions: After matching for age, sex, race, and skin type, and further adjusting for UV exposure and number of sunburns, cigarette smoking was not statistically significantly associated with melanoma risk, but the results were consistent with previous observations of an inverse association.