Parkinson’s Patients Have a Higher Risk of Developing Melano
Now open: Certificate Course in Management of Covid-19 by Govt. Of Gujarat and PlexusMDKnow more...Now open: Certificate Course in Management of Covid-19 by Govt. Of Gujarat and PlexusMDKnow more...
The relationship between Parkinson’s disease (PD) and cancer has long been a subject of study. Interestingly, patients with PD have a lower relative risk of almost all types of cancer compared with their age matched general population, but the reverse occurs with skin cancer, particularly melanoma. In the past, treatment with levodopa had been pointed out as the possible cause for this increase in the risk of melanoma in PD patients, but such association has been considered unlikely in view of later reviews addressing this subject.

In PD, there is a depletion of dopaminergic neurons in the brain, more specifically in the substantia nigra pars compacta, and dihydroxyphenylalanine (DOPA) is a common precursor of melanin and dopamine synthesis. In addition, both cutaneous melanin and neuromelanin seem to play protective roles against sun exposure in the skin and against oxidative stress in the central nervous system, respectively, and disturbances in their common pathways may contribute to explain the association between the two diseases.

The authors studied a group of over 70 000 patients with PD paired with a fivefold control group of patients aged 40 years or older. The diagnosis of PD was based on a national registry of rare intractable diseases that uses strict diagnostic criteria, a fact that, in combination with the sheer number of patients included, gives the work great reliability and statistical power.

The authors found that patients with PD were at a significantly higher risk of developing melanoma and, to a lesser extent, non-melanoma skin cancer. After adjusting for age and comorbidities, hazard ratio (HR) of developing any type of skin cancer was 1.169. The risk of developing melanoma was especially high among men older than 65 years, with a HR of 2.825. On the other hand, the relative risk of non-melanoma skin cancer was higher in female patients with PD older than 65 years, with a HR of 1.305.

The main results of this study show that the risk of melanoma in Asian patients with PD is increased. Melanoma in Asian patients is relatively rare, when compared to Caucasians, and it tends to occur mainly in acral skin (subungual and palmoplantar locations).

In conclusion, the present study confirms the increased risk of skin cancer, especially melanoma, in Korean patients with PD, providing further insight about the relationship between the two diseases. The recognition of this fact may prove useful in the determination of possible mechanisms linking both diseases and which are likely independent of factors more commonly associated with melanoma in Caucasians, such as fair skin and ultraviolet exposure.

1 share