Cutaneous melanoma is the fifth most common cancer in the United States. Modifiable risk factors, with the exception of exposure to ultraviolet radiation (UVR), are poorly understood. Coffee contains numerous bioactive compounds and may be associated inversely with melanoma. However, previous epidemiological evidence is limited.
Coffee intake was assessed at baseline with a food frequency questionnaire in the National Institutes of Health-AARP prospective cohort study. Among 447 357 non-Hispanic whites who were cancer-free at baseline, 2904 incident cases of malignant melanoma were identified during 4 329 044 person-years of follow-up, with a median of 10.5 years of follow-up. Multivariable-adjusted Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for coffee intake and subsequent melanoma risk with non-coffee drinkers as the reference group. Statistical tests were two-sided, and P values less than .05 were interpreted as statistically significant.
The highest category of coffee intake was inversely associated with malignant melanoma (≥4 cups/day: HR = 0.80, 95% CI = 0.68 to 0.93, P trend = .01). This association was statistically significant for caffeinated (≥4 cups/day: HR = 0.75, 95% CI = 0.64 to 0.89, P trend = .01) but not for decaffeinated coffee (P trend = .55).
Higher coffee intake was associated with a modest decrease in risk of melanoma in this large US cohort study. Additional investigations of coffee intake and its constituents, particularly caffeine, with melanoma are warranted.