NEW YORK — There is an unrecognized epidemic of skin cancer underway in the United States, the American Academy of Dermatology warns. One in five Americans will develop skin cancer, and a person’s risk of the disease doubles if he or she has had five or more sunburns, according to a report in the April issue of the Mayo Clinic Health Letter. Basal and squamous cell carcinomas, the most common and treatable types of skin cancers, had long been considered a problem only for people over 50, according to the report. But Mayo Clinic researchers found that the percentage of women under 40 with the more common type, basal cell, tripled between 1976 and 2003, while the rate of squamous cell cancers increased four-fold. In the same study, the researchers found that just 60% of the cancers they identified occurred on skin frequently exposed to the sun, such as the head and neck, rather than the normal 90%. Most of the remaining cancers were seen on the torso. The researchers suspect this may be due to more widespread use of tanning beds. Two types of ultraviolet (UV) light are implicated in skin cancers, the article explains. […]