CANCER AND PARKINSON'S DISEASE: THE ODD COUPLE

Epidemiological studies have consistently shown that individuals with Parkinson's disease (PD) are less likely to develop nonmelanoma cancers and vice versa. In contrast, the co-occurrence of PD and melanoma has been reported in numerous studies. The exact mechanisms underlying the observed cancer PD association are not clear. Different hypotheses have been put forward, including shared environmental/lifestyle factors (e.g., smoking and socioeconomic status) and common genetic components (e.g., parkinson protein 2 [PARK2], leucine-rich repeat kinase 2 [LRRK2], Parkinson disease [autosomal recessive, early onset] 7 [PARK7, DJ-1] and pigmentation genes). In the current review, we summarize recent findings to offer new insight into the pathogenesis of both conditions.