Patients with Parkinson’s disease may also be at an increased risk
for melanoma, according to the results of a prospective clinicopathological
According to background information of the study, a link between
Parkinson’s disease and melanoma has been suspected in the past; however,
whether an increased risk was associated with the disease itself or with
levodopa, which is used to treat the disease, was uncertain.
Results of the current study indicated that the more than twofold
increased risk was independent of treatment method.
The researchers enrolled patients from 31 centers in North America.
Patients were examined for melanoma risk factors, given a whole-body
examination, and given a biopsy for any lesions that suggested melanoma. These
data were then compared with melanoma prevalence calculated from the SEER
cancer database and the American Academy of Dermatology skin cancer screening
Of the 2,106 patients who completed the study, 84.8% had been assigned
levodopa. Among these patients, dermatologists noted 346 pigmented lesions; 294
were biopsied. Twenty of the lesions (0.9%) were in situ melanoma and four were
invasive melanomas (0.2%). An additional 68 prior melanomas (3.2%) were noted
in patient medical histories.
When data from the study were combined with any documented melanomas
diagnosed five years before baseline, 10 invasive melanomas were detected in
patients with Parkinson’s disease. Data from SEER indicated that in a
similar population of this size, age and sex, only 4.46 cases of invasive
melanoma would be expected. This indicated that the RR of invasive melanoma in
patients with Parkinson’s disease was 2.24 (95% CI, 1.21-4.17).
However, the researchers said these results must be interpreted
carefully “because of the differences in the way our data were collected
compared with the historical melanoma data recorded in the SEER database or
from [American Academy of Dermatology] screening.”
The researchers said this study provided no evidence of a relationship
between the use of levodopa and increased incidence of melanoma.
Bertoni JM. Arch Neurol. 2010;67:347-352.
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