Summary: A new study reveals people with Parkinson’s disease face a higher risk of developing melanoma skin cancer, and vice versa, than those without the diseases. Parkinson’s patients were 4 times more likely to develop skin cancer than those without the movement impairing disease. Additionally, people diagnosed with melanoma were at a fourfold risk of developing Parkinson’s.
Source: Mayo Clinic.
People with the movement disorder Parkinson’s disease have a much higher risk of the skin cancer melanoma, and vice versa, a Mayo Clinic study finds. While further research is needed into the connection, physicians treating one disease should be vigilant for signs of the other and counsel those patients about risk, the authors say. The findings are published in Mayo Clinic Proceedings.
Overall, patients with Parkinson’s were roughly four times likelier to have had a history of melanoma than those without Parkinson’s, and people with melanoma had a fourfold higher risk of developing Parkinson’s, the research found.
Medical experts have speculated about the relationship between Parkinson’s and melanoma for decades, with varying conclusions, the Mayo researchers note. Several studies have suggested levodopa, a drug for Parkinson’s, may be implicated in malignant melanoma, but others have found an association between the two diseases regardless of levodopa treatment, they add.
“Future research should focus on identifying common genes, immune responses and environmental exposures that may link these two diseases,” says first author Lauren Dalvin, M.D., a Mayo Foundation Scholar in Ocular Oncology. “If we can pinpoint the cause of the association between Parkinson’s disease and melanoma, we will be better able to counsel patients and families about their risk of developing one disease in the setting of the other.”
The Mayo study used the Rochester Epidemiology Project medical records database to identify all neurologist-confirmed Parkinson’s cases from January 1976 through December 2013 among Olmsted County, Minn., residents. The study examined the prevalence of melanoma in those 974 patients compared with 2,922 residents without Parkinson’s. They also identified 1,544 cases of melanoma over that period and determined the 35-year risk of Parkinson’s in those patients compared with the risk in the same number of people without melanoma.
The results support an association between Parkinson’s disease and melanoma, but argue against levodopa as the cause, the researchers conclude. It is likelier that common environmental, genetic or immune system abnormalities underlie both conditions in patients who have both, but more research is needed to confirm that and refine screening recommendations, they say.
In the meantime, patients with one of the two diseases should be monitored for the other to help achieve early diagnosis and treatment, and they should be educated about the risk of developing the other illness, the researchers say.
The study’s senior author is Jose Pulido, M.D., an ophthalmologist at Mayo Clinic in Rochester, Minnesota, who treats eye melanoma.
Funding: The Rochester Epidemiology Project is funded by National Institute on Aging grant R01-AG034676. Dr. Pulido received grants from the VitreoRetinal Surgery Foundation; Research to Prevent Blindness; Paul Family and Deshong Family; Dr. Dalvin received a grant from the VitreoRetinal Surgery Foundation.
Source: Sharon Theimer – Mayo Clinic
Image Source: NeuroscienceNews.com image is credited to National Cancer Institute.
Original Research: Abstract for “Parkinson Disease and Melanoma: Confirming and Reexamining an Association” by Lauren A. Dalvin, Gena M. Damento, Barbara P. Yawn, Barbara A. Abbott, Jose S. Pulido in Mayo Clinic Proceedings. Published online July 2017 doi:10.1016/j.mayocp.2017.03.014
Parkinson Disease and Melanoma: Confirming and Reexamining an Association
To examine an association between melanoma and Parkinson disease (PD).
Patients and Methods
Phase I: Rochester Epidemiology Project records were used to identify (between January 1, 1976, and December 31, 2013) patients with PD in Olmsted County, Minnesota, with 3 matched controls per case. After review, JMP statistical software with logistic regression analysis was used to assess the risk of preexisting melanoma in patients with PD vs controls. Phase II: All Rochester Epidemiology Project cases of melanoma were identified (between January 1, 1976, and December 31, 2014), with 1 control per case. A Cox proportional hazards model was used to assess the risk of developing PD after the index date in cases vs controls, and Kaplan-Meier analysis was performed to determine the 35-year cumulative risk of PD. A Cox proportional hazards model was used to assess the risk of death from metastatic melanoma in patients with melanoma without PD compared with those with PD.
Phase I: Patients with PD had a 3.8-fold increased likelihood of having preexisting melanoma as compared with controls (95% CI, 2.1-6.8; P<.001). Phase II: Patients with melanoma had a 4.2-fold increased risk of developing PD (95% CI, 2.0-8.8; P<.001). Kaplan-Meier analysis revealed an increased 35-year cumulative risk of PD in patients with melanoma (11.8%) compared with controls (2.6%) (P<.001). Patients with melanoma without PD had a 10.5-fold increased relative risk of death from metastatic melanoma compared with patients with melanoma with PD (95% CI, 1.5-72.2) (P=.02).ConclusionThere appears to be an association between melanoma and PD. Further study is warranted; but on the basis of these results, physicians may consider counseling patients with melanoma about PD risk and implementing cutaneous and ocular melanoma surveillance in patients with PD.“Parkinson Disease and Melanoma: Confirming and Reexamining an Association” by Lauren A. Dalvin, Gena M. Damento, Barbara P. Yawn, Barbara A. Abbott, Jose S. Pulido in Mayo Clinic Proceedings. Published online July 2017 doi:10.1016/j.mayocp.2017.03.014