Citrus Consumption and Risk of Cutaneous Malignant Melanoma in the Women's Health Initiative.

Citrus products are rich sources of furocoumarins, a class of photoactive compounds. Certain furocoumarins combined with ultraviolet radiation can induce skin cancer. We examined the relationship between citrus consumption and cutaneous melanoma risk among 56,205 Caucasian postmenopausal women in the Women's Health Initiative. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of melanoma by citrus intake level. During a mean follow-up of 15.7 years, 956 incident melanoma cases were documented. In multivariable adjusted models, the HR (95% CI) for melanoma was 1.12 (0.91, 1.37) among the highest citrus consumers (1.5+ servings/day of fruit or juice) versus the lowest (<2 servings/week), 0.95 (0.76, 1.20) among the highest citrus fruit consumers (5+ servings/week) versus non-consumers, and was 1.13 (0.96, 1.32) for the highest citrus juice consumers (1+ servings/day) versus the lowest (<1 serving/week). In stratified analyses, an increased melanoma risk associated with citrus juice intake was observed among women who spent the most time outdoors in summer as adults; the HR for the highest versus lowest intake was 1.22 (1.02, 1.46) (p trend = 0.03). Further research is needed to explore the association of melanoma with citrus juices among women with high sun exposure.