Milder types of skin cancer may raise melanoma risk

By Amy Norton

NEW YORK (Reuters Health) - Women who've had common, highly curable forms of skin cancer may face a heightened risk of the deadlier skin tumor melanoma, researchers have found.

Their study of more than 67,000 white postmenopausal women found that those with a history of non-melanoma skin cancer were 70 percent more likely than other women to develop melanoma during the study period.

That was after factors such as age, family history of cancer and past sun exposure were taken into account.

The findings suggest that there are genetic influences that make some people vulnerable to both melanoma and non-melanoma skin cancers, explained study chief Dr. Carol A. Rosenberg, director of preventive health initiatives at Evanston Northwestern Healthcare in Illinois.

She and her colleagues report the findings in the current issue of the journal Cancer.

Two forms of non-melanoma skin cancer -- basal cell and squamous cell -- account for the large majority of skin cancer cases, and are rarely fatal themselves. Based on the new findings, though, the diseases can be added to the list of risk factors for the deadlier melanoma, according to Rosenberg.

The results are based on data from the Women's Health Initiative, a large study of U.S. women begun in 1994 that collected detailed health and lifestyle information and followed up with participants annually.

Overall, more than 5,500 women had a history of non-melanoma skin cancer, but no other cancer, at the study's outset. These women, Rosenberg and her colleagues found, were at increased risk of developing melanoma over 6.5 years, regardless of other key risk factors.

According to Rosenberg, women with a history of non-melanoma skin cancer should be sure to have thorough skin examinations at frequent intervals to catch any new lesions early.

"Melanomas caught early are curable," she said, "and critical to saving lives of those predisposed to it."

SOURCE: Cancer, February 1, 2006.