Recent findings indicate there may be a link between Parkinson’s disease and melanoma, with family history and common genetic susceptibility as possible causes. The review is published in the journal Dermatologic Surgery and is titled “A Review of the Association Between Parkinson Disease and Malignant Melanoma.”
Since the 1970s and following the start of levodopa (L-DOPA) treatment for patients with Parkinson’s disease, neurology and oncology scientific literature have raised suspicions about a possible link between melanoma and Parkinson’s. This is because a number of case reports suggest that levodopa has a causal relationship with malignant melanoma due to its shared dopamine biochemical pathway.
“Given that [levodopa] is a substrate in melanin synthesis, there existed a concern that this therapy [for Parkinson’s disease] might cause melanoma,” researchers wrote in their review.
To explore published evidence on possible casual links that can explain the associations between Parkinson’s and melanoma, Max Disse from the University of Minnesota Medical School in Minneapolis and colleagues conducted a literature search of PubMed and Google Scholar using the terms “Parkinson’s disease, Parkinson’s, melanoma, melanoma + Parkinson’s disease, alpha-synuclein and melanoma,” and other combinations of these same words.
From the studies, the authors found that patients with Parkinson’s have an overall 27 percent decreased risk of cancer diagnoses. However, melanoma and breast cancer were found to have an unusually high rate of co-occurrence with Parkinson’s.
A family history of melanoma, along with lighter hair and skin color, were found to be linked with a higher risk of developing Parkinson’s. A first-degree relative with either disease was found to increase the risk of developing the condition. Other possible associations identified included pigmentation genes in neural-derived cells, MC1R polymorphisms, abnormal cellular autophagy, and pesticides.
“Both Parkinson’s disease and melanoma are likely multifactorial diseases including genetic and environmental risk factors, and further research will be needed to completely evaluate this link,” the researchers wrote. “It is prudent that dermatologists be aware of this increased risk of melanoma and explain this risk to their patients with Parkinson’s and recommend them sun protection, self-surveillance, and periodic skin check-up.”