Coffee Consumption and Melanoma: A Systematic Review and Meta-Analysis of Observational Studies

Laboratory and animals studies have suggested a possible protective effect of coffee consumption on the development of melanoma. However, the results of epidemiological studies investigating this association have been inconclusive. A systematic review and meta-analysis of published studies was conducted to evaluate any association between coffee consumption and melanoma. Observational studies were searched for in MEDLINE, EMBASE, and the Cochrane Central Register from inception to September 1, 2015. The Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines were followed in conducting this study. We identified nine observational studies with a total of 927,173 study participants, of which 3787 had melanoma. With random-effects modeling, the pooled relative risks (RR) for melanoma among regular coffee drinkers was 0.75 (95 % confidence interval [CI] 0.63–0.89, p = 0.001) compared with controls. Visual inspection of a funnel plot suggested publication bias, although Egger’s test (p = 0.981) delineated no small-study effects. The pooled relative risks for melanoma among decaffeinated coffee drinkers was, however, not statistically significant at 0.92 (95 % CI 0.82–1.05, p = 0.215). There is some evidence for the beneficial effects of regular coffee consumption on melanoma. More prospective cohort studies with systematic quantification of coffee consumption would be necessary to further elucidate this association.