http://www.pnas.org/cgi/content/full/98/13/7510

"Epidemiological and animal-based investigations have indicated that the
development of skin cancer is in part associated with poor dietary
practices. Lipid content and subsequently the derived fatty acid composition
of the diet are believed to play a major role in the development of
tumorigenesis."

"the development of skin cancer has also been reported to be related to
dietary factors, including dietary lipids. Epidemiological and experimental
studies have shown that different classes of dietary fatty acids have a
variety of effects on tumor development."