Parkinson’s disease may raise skin cancer risk
MedWire News: People with Parkinson's disease have an increased chance of developing a dangerous form of skin cancer, researchers believe.
Their study found that men and women with Parkinson's disease had twice the risk for malignant melanoma compared with people without the disease.
"One possible explanation for the link between Parkinson's and melanoma is that the two diseases may share some genetic or environmental risk factors," said Honglei Chen, the study's lead author, from the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina, USA. "However, our understanding of this link is very preliminary."
Parkinson's disease is a brain disorder that causes tremors and difficulty with movement and walking. In general, Parkinson's sufferers have a below-average likelihood of developing cancer, especially cancers associated with smoking.
Recently, however, there have been reports of skin cancer in patients with Parkinson's disease who are being treated with a drug called levodopa, raising suspicions of a link between either Parkinson's itself or levodopa therapy and melanoma.
To investigate further, Chen and co-workers searched the medical literature and found 12 relevant studies, which they then combined for analysis. This revealed that patients with Parkinson's disease were more than twice as likely to develop melanoma as people without the brain disorder.
Parkinson's disease was not associated with an increased risk for other forms of skin cancer, however.
Commenting on their study, Chen and colleagues say that the underlying causes of the increased melanoma risk in Parkinson's suffers is unclear; however, their study argues against levodopa therapy being a cause, as the risk was increased even before Parkinson's disease had been diagnosed.
They conclude: "Further research is needed to examine the nature and mechanisms of this relationship in order to advance our understanding about the etiology of both diseases."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Joanna Lyford