Analysis of Parkinson's disease and subsequent cancer risk in Taiwan: a nationwide population-based cohort study.

Background: Patients with Parkinson's disease (PD) are suggested to be at a lower risk for the development of certain cancers and at a higher risk for melanoma. The aim of this study is to evaluate the possible association between PD and malignancy in Taiwan.
Materials and Methods: We used the data of the National Health Insurance System of Taiwan to assess this issue. The PD cohort contained 4,957 patients, and each patient was randomly frequency matched by age and sex with 4 people from the general population without PD. Cox's proportional hazard regression analysis was conducted to estimate the effects of PD on the cancer risk.
Results: In patients with PD, the risk of developing overall cancer was marginally significantly lower than in subjects without PD [adjusted hazard ratio (HR) = 0.88; 95% CI = 0.78-0.99]. For individual cancers, the risks of developing colorectal and lung cancers among patients with PD were marginally significantly lower than in subjects without PD. In contrast, despite the higher HR for the development of melanoma, it did not reach statistical significance because of the relatively small sample size.
Conclusion: Our study found that Taiwanese patients with PD have a lower risk of developing colorectal and lung cancers. The findings of this study are compatible with those of prior studies from other countries.
(Copyright © 2011 S. Karger AG, Basel.)