Research Notes — Study links Parkinson’s disease with skin cancer melanoma

A recent study published in the Archives of Neurology journal has revealed a link between Parkinson’s disease and melanoma, the most dangerous type of skin cancer.

picture disc.The 31-center study, which involved more than 2,100 patients in the United States and Canada, showed that people who have Parkinson’s disease were 2 to 7 times more likely to develop melanoma.

John Bertoni, M.D., Ph.D., professor of neurological sciences at UNMC and principal investigator of the study, said why there is an increased risk of melanoma in patients with Parkinson’s disease is a mystery.

“We don’t know why people with Parkinson’s are more prone to develop melanoma,” he said. “It could have something to do with ancestry. If a person has fair skin, blond or red hair, and doesn’t tan easily, they are more likely to get melanoma. Parkinson’s disease may play a role in that.”

There are several theories linking melanoma and Parkinson’s disease, he said.

One of which is that the same area in the brain affected by Parkinson’s, the substantia nigra, has melanin, a skin pigment.









picture disc.

John Bertoni, M.D., Ph.D.
Another theory is that levodopa, the leading drug therapy for Parkinson’s, is converted to melanin and is used as a building block for making pigment in the brain.

“But this doesn’t explain the link. These are just clues,” Dr. Bertoni said.

What Dr. Bertoni found in his study is that medications have no direct impact on whether or not a person will develop melanoma.

In fact, he cites data from a survey of patients in Denmark and a study in Minnesota that “suggest the increased incidence of melanoma is related to Parkinson’s disease rather than to treatments.”

Parkinson’s disease affects more than 4 million people worldwide, while more than 68,000 cases of melanoma were diagnosed in 2009.

“The bottom line is if you have Parkinson’s disease, be sure to get checked out by a dermatologist,” Dr. Bertoni said. “The vast majority of all the melanomas that were found in our study were so small that the biopsy itself removed the entire skin cancer.”