Turning the corner on the fight against melanoma

A recent study could mean a major breakthrough for how melanoma is treated in the future. A study published in today's New England Journal of Medicine concludes that there is more than one type of melanoma. The melanomas caused by sun-damaged skin differ from those found in less sun-exposed areas of the body. And it is suggested that doctors may not always be treating the correct type of melanoma because the perception has been that there is basically only one. This is big news in the fight against melanoma.

Excerpts from HealthDay:

As with other cancers, scientists are learning that not all melanoma skin cancers are genetically alike. And that may have far-reaching implications for the treatment and prevention of melanoma.

A new study reports that, depending on the area of the body affected by melanoma, there are at least several distinct types of the disease: Those arising from chronically sun-damaged skin and those on skin without sun damage; those that occur on areas rarely exposed to sun, such as the palms and soles of feet; and melanomas that occur on mucous membranes.

"Up to now melanoma was regarded as one disease and was treated as such. But our study shows there are marked genetic differences in melanoma cases. These are distinct diseases," said study author Dr. Boris Bastian, an assistant professor of dermatology and pathology at the University of California, San Francisco.

"Melanoma is an awful disease if it can't be surgically cured," said Dr. Paul Meltzer, head of the section of molecular genetics in the cancer genetics branch at the National Human Genome Research Institute, in Bethesda, Md.

Bastian and his colleagues compared 126 different melanomas from four groups that all received differing levels of ultra-violet (UV) light exposure from the sun. Thirty melanomas were from skin that showed signs of chronic sun damage, while 40 were from skin that didn't show signs of sun-induced damage. Another 36 melanomas were from areas that are rarely exposed to sun, such as the palms and soles of the feet. The remaining 20 melanomas occurred on mucous membranes, such as those found in the mouth, nose and genital areas.

When they compared these melanomas from different areas of the body, the researchers found significant genetic differences that often correlated with the location of the melanoma.

"The bottom line is that there are distinct sets of melanoma," said Bastian.

Meltzer, who wrote an accompanying editorial in the same issue of the journal, said this study "may have significant clinical implications in the long run," and is "laying the groundwork for a better individualized and personalized cancer therapy."

"I'm somewhat optimistic now that we may turn the corner on melanoma therapy," he added.

Both Bastian and Meltzer said one of the reasons current melanoma therapies might not be as effective as doctors would like them to be is that they may not be targeting the right type of melanoma.

"These findings may be very important for designing targeted therapies for these various types," said Bastian.