Melanoma With Parkinson’s More Often Found on Head and Neck
Study to guide patients' skin cancer checks finds 43.9% of tumors in those 2 regions
Among people diagnosed with melanoma, a type of skin cancer, the tumor is twice as likely to be found along the head or neck if they also have Parkinson’s disease, a study found.
These findings support the importance of screening these regions for more accurate melanoma surveillance in Parkinson’s patients, who are known to have a higher risk of melanoma, the researchers noted.
The study, “Clinicopathologic characteristics of melanoma in Parkinson’s disease patients,” was published in the journal JID Innovations.
Link indicated between Parkinson’s disease and melanoma
Several studies have reported that Parkinson’s patients have a lower risk of certain cancers such as colorectal cancer, but higher risk of others, including melanoma.
This higher melanoma risk is thought to be associated with several factors, such as deficient production of melanin, a natural skin pigment, in skin cells due to excessive alpha-synuclein protein levels — a hallmark of Parkinson’s.
Prior research also suggested that levodopa, a mainstay Parkinson’s treatment, could contribute to the development of melanoma. However, people with melanoma also are reported to be at a higher risk of Parkinson’s, suggesting otherwise and pointing to shared underlying mechanisms between the two conditions.
Information on melanoma in Parkinson’s patients, which could help guide surveillance and prevention efforts, however, is somewhat limited.
Researchers at Duke University retrospectively analyzed the clinical features of melanoma in 70 adults also diagnosed with Parkinson’s, and 102 age-, sex-, and race-matched adults with melanoma but not Parkinson’s, as controls.
Both groups were followed at the Duke University Medical Center between January 2007 and January 2020.
Data for the 184 melanomas detected in these patients (82 in the Parkinson’s group) included the primary tumor’s location, subtype, staging, tumor invasiveness and metastasis, and treatment.
Of note, a tumor’s invasiveness refers to its ability to spread beyond the layer of tissue in which it first developed; metastasis refers to the spread of tumors through the bloodstream to distant sites in the body.
Parkinson’s patients were mostly male (72.9%) and Caucasian (98.6%), 12.9% had a family history of the neurodegenerative disease, and their median age at Parkinson’s diagnosis was 72.3. Melanoma was diagnosed before Parkinson’s in 61.4% of the cases (43 people), with a median of 2.3 years between the two diagnoses.
This finding adds to previous studies into Parkinson’s and melanoma, further suggesting “the possibility of an alternative [disease-associated] link between the disease processes beyond the previously reported association with levodopa,” the researchers wrote.
Most tumors (47.6%) in the Parkinson’s group were stage 0, melanoma in situ, meaning that cancer cells were still confined to the very outer layer of the skin. Among controls, stage 1 melanomas (relatively thin and limited to the skin) were most common (33.3%), followed by malignant melanoma in situ (22.5%).
A primary melanoma in the Parkinson’s group was typically found in the head and neck region (43.9%), and on the trunk among controls (31.4%).
Among all head and neck region primary tumors, 39.5% were invasive in Parkinson’s patients as were 25.3% among controls. Most (48.7%) were non-invasive tumors in the Parkinson’s group (39.1% among controls).
Few metastatic tumors seen in study also typically on head or neck
Although metastatic tumors were rare, half of these tumors in Parkinson’s patients also started in the head/neck region, compared with 42.9% in the control group.
Parkinson’s patients were twice as likely to have melanoma in the head or neck region than people without this disease, further analyses showed.
In addition, a higher proportion of Parkinson’s patients had a history of a prior skin cancer, particularly squamous cell carcinoma (26.5%) and basal cell carcinoma (36.2%). Among controls, these histories were 9.8% and 19.6%, respectively.
Given these results, “increased screening for melanoma in [Parkinson’s] patients with a particular focus on the head and neck [is advised], as most non-invasive, invasive, and metastatic melanomas originated from these anatomic locations,” the team wrote.
Researchers also favored “increased surveillance for melanoma” in people newly diagnosed with Parkinson’s, “as early detection may result in a more favorable prognosis,” they added.
They also highlighted the importance of keeping Parkinson’s symptoms, such as tremors, rigidity, difficulty walking or unusual falls, in mind when diagnosing melanoma.
“Strategies for mitigating fall risk include employing assistance from healthcare staff or patient family members during the removal of clothing,” which can allow for “skin examinations of one body segment at a time, and examining the head and neck, upper extremities, and trunk while patients are seated,” the team wrote.
This study’s small number of Parkinson’s patients and lack of diversity in terms of race, ethnicity, and sex may limit the generalization of its findings, the researchers noted.
“It is important to recognize that [Parkinson’s] and melanoma may develop independently with advancing age, that older non-Hispanic white males are a demographic group at high risk for head and neck and thick melanomas independent of [Parkinson’s] diagnosis,” they wrote, adding “the results of our study are insufficient to confirm a definite link.”
Larger studies are needed to validate these findings, they wrote.
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