Dietary pattern in association with squamous cell carcinoma of the skin: a prospective study

BACKGROUND: The role of diet in the development of skin cancer is inconclusive, and the effect of the combined consumption of foods has never been reported. OBJECTIVE: We prospectively investigated the association between dietary patterns and cutaneous basal cell (BCC) and squamous cell (SCC) carcinoma. DESIGN: Principal components analysis of 38 food groups was used to identify dietary patterns in 1360 adults aged 25-75 y who participated in a community-based skin cancer study in Nambour, Australia, between 1992 and 2002. We obtained baseline information about diet, skin color, and sun exposure factors. Multivariate-adjusted relative risks (RRs) for BCC and SCC tumors were estimated by using negative binomial regression modeling. RESULTS: Two major dietary patterns were identified: a meat and fat pattern and a vegetable and fruit pattern. The meat and fat pattern was positively associated with development of SCC tumors (RR=1.83; 95% CI: 1.00, 3.37; P for trend=0.05) after adjustment for confounders and even more strongly associated in participants with a skin cancer history (RR=3.77; 95% CI: 1.65, 8.63; P for trend = 0.002) when the third and first tertiles were compared. A higher consumption of the vegetable and fruit dietary pattern appeared to decrease SCC tumor risk by 54% (P for trend = 0.02), but this protective effect was mostly explained by the association with green leafy vegetables. There was no association between the dietary patterns and BCC tumors. CONCLUSION: A dietary pattern characterized by high meat and fat intakes increases SCC tumor risk, particularly in persons with a skin cancer history.