Skin Cancers Triple Among Those Under 40

The incidence of two forms of skin cancer has tripled among people under 40 -- particularly women -- an increase scientists attribute to tanning’s continued allure and Earth’s diminishing ozone layer.

Researchers from the Mayo Clinic in Minnesota say rates of basal and squamous cell carcinomas have risen dramatically over the last quarter century, despite repeated public health messages about the importance of sunscreen and protective clothing. The two cancers normally are seen in people over 50. On rare occasions, doctors said Tuesday, the cancers have been diagnosed in teens and preteens.

“This has been evolving over time, and it has just gotten to the point where it has hit our radar screen,” said Dr. Leslie Christenson, a dermatologic surgeon at the Mayo Clinic whose study is reported in the current issue of the Journal of the American Medical Assn. “Parents are good about putting sunscreen on children but as children reach their adolescent years, parents are no longer allowed to do that.”

She and her team examined the health records of 500 people living in Olmsted County, Minn. She said the population was mostly white and was representative of most white populations throughout the country. As a result, the findings can be extrapolated to people living elsewhere.

The two malignancies, most common among people with fair complexions and red or blond hair, differ in terms of how they look and grow. Both develop on the skin’s surface and tend not to spread to distant parts of the body as would melanoma, their deadlier cousin. However, if left untreated, squamous cell carcinoma can invade deeper and metastasize.

All told, 800,000 new cases of basal carcinoma and 200,000 of squamous cell cancer are reported annually in the U.S. But the analysis found an alarming trend. In 2003, there were 32 cases of the cancers per 100,000 people under age 40 compared with 13 per 100,000 in the late 1970s. More than 56% of the cancers were in women.

Doctors not connected with the research also have noticed a recent upsurge in cases among younger people, especially women.

“We used to see these cancers only in older patients,” said Dr. Elizabeth Hale, a dermatologic surgeon at New York University Medical Center in Manhattan.

Hale also pointed to the use of tanning salons as a major cause of basal and squamous cell skin cancers.