Pediatric Melanoma More Common in Melanoma-Prone Families

October 4, 2018
Leah Lawrence
Leah Lawrence

The percentage of patients with pediatric melanoma is 6-fold to the 28-fold higher when compared with the general population of patients with melanoma.

Families classified as melanoma-prone have a 6-fold to 28-fold higher percentage of patients with diagnosed pediatric melanoma compared with the general population of patients with melanoma, according to a study published in Cancer. This increased risk occurred regardless of CDKN2A mutation status.

“These observations have implications for the prevention of melanoma as well as clinical care for its early detection,” wrote study author Alisa M. Goldstein, PhD, of the National Cancer Institute, and colleagues. “Children in melanoma-prone families should have careful sun protection from an early age and skin surveillance to reduce their risk of melanoma.”

Pediatric melanoma, or melanoma occurring in patients aged younger than 20 years, is a rare disease. Melanoma-prone families have a reduced age at diagnosis and increased risk for multiple primary melanomas. In addition, germline mutations in the gene CDKN2A, a tumor suppressor gene, are found in some melanoma-prone families.

In this study, Goldstein and colleagues evaluated the occurrence of pediatric melanoma in those melanoma-prone families, regardless of CDKN2A mutation. They followed a total of 60 families for up to 40 years. Families had three or more patients with melanoma. An equal number of families with and without CDKN2A mutations were included.

Of 311 confirmed cases of melanoma diagnosed in the 60 families, 7.7% were pediatric cases. The majority of pediatric cases (21 of 24) were diagnosed in CDKN2A-positive families. The median age at time of first melanoma diagnosis was 16.5 years.

The researchers calculated that melanoma-prone families that were CDKN2A-negative had 6-fold higher percentages of pediatric melanoma, and those that were CDKN2A-positive had 28-fold higher percentages of melanoma, compared with a SEER-based melanoma patient population.

In addition, pediatric patients from CDKN2A-positive families were significantly more likely to have multiple primary melanomas compared with relatives diagnosed after age 20 years (P = .004).

“This observation is consistent with what has been noted in the general population of patients with melanoma, in which individuals who develop melanoma at an early age also are at higher risk of developing subsequent melanomas compared with older individuals,” the researchers wrote. “The risk of second primary melanoma in individuals aged 50 years is increased 8-fold.”

Commenting on the study, Alberto Pappo, MD, director of the solid tumor division at St. Jude Children’s Research Hospital, said that this study is an important reminder that taking a thorough family history is vital.

“Although routine testing for mutations in genes that predispose to melanoma is not indicated in cases of sporadic childhood melanoma, identification of carriers in high-risk families could help improve adherence to sun safe behaviors, such as limiting exposure to the sun in peak times, and use of sun blockers,” Pappo said.

“Once you identify a high-risk patient, even if they don’t have melanoma, the most important thing to do to prevent death from this disease is early detection and treatment,” he told Cancer Network.

Pappo also stressed the importance of prevention in these patients.

“Although it is highly recommended in the general population, in a family at high-risk of melanoma, prevention is of utmost importance,” Pappo said. “There is a possibility of mitigating that risk by education, counseling, and skin surveillance to prevent or detect early melanoma in these melanoma-prone families.”