Parkinson’s patients have double the risk of melanoma
Parkinson’s disease patients have double the risk of developing potentially lethal melanoma, researchers reported on Tuesday (7 June 2011). Researchers have long suspected such a link, but the new study, reported in the journal Neurology, provides the strongest evidence to date.
Parkinson’s disease patients have double the risk of developing potentially lethal melanoma, researchers reported on Tuesday (7 June 2011). Researchers have long suspected such a link, but the new study, reported in the journal Neurology, provides the strongest evidence to date.
While researchers are at a loss to explain how the link occurs biologically, they suspect it may be a combination of environmental exposure and genetic predisposition.
Experts say the discovery is particularly “strange” because Parkinson’s patients, in general, have a below-normal risk of developing most types of cancer.
Establishing a link between Parkinson’s and melanoma is difficult because both are relatively rare diseases.
To increase the chances of finding statistically significant results, Dr Honglei Chen, a neuroscientist at the National Institute of Environmental Health Sciences in Research Triangle Park, New York City, and colleagues combined the results from 12 studies conducted between 1965 and 2010.
Overall, the researchers found the risk of melanoma was 2.11 times normal in Parkinson’s patients.
The team found the risk of melanoma was 2.04 times normal for men and 1.52 times normal for women.
The risk of diagnosis of melanoma was significantly higher after Parkinson’s had been diagnosed. The team found no link to non-melanoma skin cancers.
Many experts had thought the increased risk of melanoma was produced by levo-dopa, the most common treatment for Parkinson’s disease.
But Dr Chen discarded the link, and suggested the same high risk of melanoma is associated with patients who have not received the drug.
Some studies have shown pigmentation might also contribute to the risk of melanoma, as lighter hair colour is associated with an increased risk of Parkinson’s and of melanoma.
However, researchers concluded further research was needed to clarify the link between the two diseases.
