NEW YORK (Reuters Health) - People with Parkinson's disease face an
increased risk of the most deadly type of skin cancer, new research
confirms.
Exams of more than 2,000 people with Parkinson's disease found that about 1
percent currently had melanoma, Dr. John M. Bertoni of the University of
Nebraska Medical Center in Omaha and his colleagues found. Based on the
findings, they say, people with the degenerative nerve disease should
receive regular skin cancer screening.
A number of studies have found a higher risk for melanoma among people with
Parkinson's disease, which occurs when brain cells that produce dopamine --
a signaling chemical with many important functions in the brain -- die off.
But it hasn't been clear whether this increased risk is due to the drugs
people take to treat Parkinson's disease or to the disease itself.
To investigate further, Bertoni and colleagues at 31 different centers
across North America studied 2,106 patients with Parkinson's disease. The
patients first underwent a neurological exam, and then at a second visit had
a dermatologic exam, which included biopsies of any suspicious moles or
growths.
The researchers found 20 localized melanomas among the study participants
and 4 that had spread beyond the original site, while another 68 patients
reported having a history of melanoma.
Among the patients living in the US, the likelihood of having melanoma was
more than double that of the general US population, the researchers found.
When the findings were compared to statistics from skin cancer screening
programs run by the American Academy of Dermatology, the researchers found a
more than seven-fold increased risk of melanoma for US Parkinson's patients.
Since the 1970s, a number of case reports have suggested that levodopa
therapy for Parkinson's disease increases the risk of skin cancer. In the
current study, nearly 85 percent of the patients had taken levodopa, but the
researchers found no evidence that this drug was associated with melanoma
risk.
This study, conclude Bertoni and colleagues, provides more evidence that
melanoma occurs more often in patients with Parkinson's disease than in the
population at large and "supports increased melanoma screening" in patients
with Parkinson's disease.
SOURCE: Archives of Neurology
