High prevalence of malignant melanoma in Israeli patients with Parkinson's disease

Abstract

The risk of melanoma is higher in patients with Parkinson's disease (PD) than in the general population. Whether the association is disease related or treatment related is unclear. The objective of this study was to assess melanoma prevalence in PD patients in Israel using active dermatologic screening. Consecutive patients with idiopathic PD were recruited by 12 Israeli centers. A movement disorder specialist assessed the severity of PD and obtained a medical, neurological, and medication history. Subsequently, a dermatologist assessed melanoma risk factors, recorded a dermatologic history, proactively performed a whole-body skin examination, and biopsied suspicious skin lesions. Of the enrolled patients (n = 1,395, mean age 69.5 ± 10.6 years, mean PD duration 7.3 ± 6.0 years), 95.3% were treated with dopaminergic agents. Biopsies revealed 8 patients with melanoma in situ and 1 with invasive malignant melanoma; 14 patients reported a melanoma prior to enrollment. The observed 5-year limited duration prevalence of melanoma in PD patients was 4.4 times greater (95% CI 2.6-7.6) than expected from melanoma prevalence in an age- and sex-matched cohort from the Israel National Cancer Registry. The increase was accounted for by an elevated prevalence of melanoma in situ [relative risk 12.5 (95% CI 6.7-23.2)]. Occurrence of melanoma did not correlate with levodopa therapy or time of onset of PD. Melanoma prevalence in PD patients was higher than expected in the general Israeli population. This was not related to levodopa treatment. PD patients should be actively screened for melanoma on a routine basis.