Parkinson's disease and skin cancer risk: a nationwide population-based cohort study in Korea.

BACKGROUND: Previous studies have reported that patients with Parkinson's disease (PD) have a significantly lower risk of cancer. Studies reporting prevalence of skin cancers in Parkinson's disease mostly involve Caucasians. OBJECTIVE: A nationwide population-based study was conducted to determine the risk of skin cancer in patients diagnosed with PD in Korea. METHODS: Data obtained from National Health Insurance Claims records were used to retrieve information about 70 780 patients with newly diagnosed PD between January 2010 and December 2015. The control group included 353 900 sex- and age-matched patients without PD. In this nationwide population-based cohort study, we investigated the association between PD and skin cancer. RESULTS: The overall hazard ratio (HR) of skin cancers in patients with PD was 1.169 (95% CI, 1.005-1.359) compared with non-PD group. Among patients with PD, males aged above 65 had a 2.8-fold increase in the risk for melanoma development than the non-PD group (HR, 2.825; 95% CI, 1.395-5.721). In addition, female PD patients aged above 65 years showed a 1.3-fold increase in non-melanoma skin cancer risk than the non-PD group (HR, 1.305; 95% 1.073-1.589). CONCLUSION: Compared with the general population, Korean patients diagnosed with PD had a greater risk of skin cancer. Especially, male patients aged 65 years and above, and diagnosed with PD had a significant risk of melanoma development compared with control.