Smoking, Parkinson's Disease, and Melanoma Available to Purchase

In Response: We appreciate Dr. Grant's observation that smoking is associated with a decreased risk of melanoma in some epidemiologic studies. This is of note, as there is a well-established decreased risk of Parkinson's disease among smokers as well (1). Our study confirmed previous findings that Parkinson's disease is associated with an increased risk of melanoma. In contrast, the risk of most other cancers seems to be decreased, particularly those related to smoking. Dr. Grant suggests that the same mechanism that confers a lower risk of smoking-related cancer in Parkinson's disease may also explain the higher risk of melanoma in these patients. Whereas this is an intriguing hypothesis, the nature of our cuurent data does not allow us to provide biological explanations for the cancer pattern we have observed in patients with PD. However, as evidenced by Dr. Grant's comments, our findings may serve to generate questions about...