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Recurrent Melanoma More Prevalent Than First Thought

Posted: April 19, 2006

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Roughly two-thirds of those who developed additional malignancies and 37 percent of those who did not had at least one atypical mole, which is a risk factor for additional melanomas. Someone with three or more atypical moles had four times the risk of developing an additional tumor. Atypical moles have at least three of the following features -- a diameter larger than 5 millimeters; redness; an irregular or ill-defined border; a variety of colors or a portion that is flat, the researchers said.

In one-third of the patients who developed another melanoma within two years, the subsequent melanoma was deeper than the first.

The study found little relationship between risk and benign moles, eye and hair color, or length of sun exposure. There was, however, a surprising inverse relationship between blistering sunburn and melanoma -- those with a history of sunburn were less likely to develop a second melanoma than those without, the researchers wrote. But this finding "must be viewed cautiously," the researchers said. It's possible that people who are predisposed to multiple melanomas may be less vulnerable to sunburn than those who get only one melanoma, or there may be a separate reason for the finding, the researchers said.

Another study in the same issue of the journal reported that nearly half of high schools surveyed in the Denver area contained advertisements for tanning parlors in their newspapers.

The ultraviolet (UV) radiation used in tanning parlors is a known carcinogen. The authors of the study, led by Dr. Scott Freeman, of the University of Colorado at Denver and Health Sciences Center, called for cancer-prevention policies that prohibited UV tanning advertising to minors.