Estimates indicate that each year in the United States, there are about 400 new diagnosis of melanoma among those younger than 19 years of age. According to the St. Jude Children’s Research Hospital, melanoma is the most common skin cancer type occurring in children 15 to 19 years of age, accounting for about 7% of all cancers diagnosed in that age group. Luckily, most melanomas are diagnosed early and are highly treatable.
Alberto Pappo, MD, director of the solid tumor division at St. Jude Children’s Research Hospital, was asked in a recent interview about melanoma risk factors in children and the different types of treatment options available.
During the interview, reported in HemOnc Today, Dr. Pappo addressed issues like how typical is the diagnosis of child melanoma and which are the most updated estimates. He mentioned that the occurrence of melanoma in children is not well understood, and that it depends on how clinicians define melanoma, as the term has been used for many different disease types. He further clarified that in pediatrics, the most typical melanoma is known as spitzoid melanoma, which has a different course and requires different treatment from melanomas diagnosed in adult patients.
Dr. Pappo explained that the proportion of children at risk for melanoma is small. He further explained that children with large back moles — a rare condition known as giant congenital melanocytic nevus — have a different disease course. In these cases, within the first 10 years of life, approximately 5% of these children will develop melanoma. Dr. Pappo further noted that people who received treatments with immunosuppressants such as chemotherapy or renal transplant are more predisposed to develop nevi or moles, and consequently might be at increased risk for melanoma. “There are also genetic conditions that are associated with an increased risk for developing melanoma, but these are extremely rare. One of these is called xeroderma pigmentosum and these patients usually go on to develop carcinomas but a small number of these patients may develop melanoma,” Dr. Pappo said. Hereditary retinoblastoma survivors are also at increased risk for melanoma, he said.
Children who are diagnosed with melanoma within the first 20 years of their life share identical traits with those observed in adults with melanoma. These factors include a history of sunburns, a light complexion, freckles and red hair. However, according to Dr. Pappo, the reason as to why melanoma occurs at age of 14 and not at 40 remains unknown. “We conducted a genomic analysis of pediatric melanoma here at St. Jude (the first comprehensive genomic analysis on pediatric melanoma in the world) and we were unable to identify the exact reasons why younger patients develop melanoma. We were, however, able to confirm that if a child develops a conventional melanoma just like the one seen in adults, the genomic profile of the tumor is almost identical to that seen in adults, including evidence that ultraviolet radiation plays a role in the disease,” Dr. Pappo clarified.
When asked about the best prevention measure to be taken with children, Dr. Pappo pointed to the importance of regular sunscreen use that is of a broad spectrum (efficacious against UVA and UVB rays), water-resistant, and of at least 15 SPF. He also stated that the evidence that sunscreens above 50 SPF have more protective effects is limited. Dr. Pappo recommended that no more than two hours should go by between sunscreen applications (including water-resistant ones), and that children should not be exposed to sun between 10 a.m. to 2 p.m. For babies younger than 6 months of age, no sun at all is the best prevention measure. Even though these infants can be at the beach, they should be properly covered rather than treated with sunscreens, as exposure to the chemicals in sun blockers is not recommended for infants under 6 months.
Dr. Pappo was then questioned about the current available treatment options for children with a diagnosis of melanoma. He clarified that this depends on the type of melanoma, but if it’s a typical melanoma, clinicians follow the adult treatment guidelines. “With the study we conducted at St. Jude showing that a subset of melanomas in children are exactly the same as in adults, we believe that clinical trials should be made available for younger patients particularly adolescents. However, there are a variety of approved therapies in adults that we can apply to pediatric patients such as interferon, which we have been using at St. Jude for many years, as well as other targeted treatments such as BRAF inhibitors and immune treatments such as check point inhibitors. However, we have no direct access to new therapies being tested in adults,” Dr. Pappo said.
When asked about the clinical prognosis for children with a diagnosis of melanoma, Dr. Pappo noted that children with melanoma who received their diagnosis after the age of 10 years have a specific melanoma subset identical to the one found in adults, meaning that if the diagnosis is made at an early stage of the disease, the probability of a successful cure is high. “I would say more than 90% of children with melanoma are expected to be cured of their disease. However, prognosis is directly related to the stage of the disease, and if the melanoma has metastasized to lymph nodes or distant metastases, then the outcomes are very poor — anywhere between 10% to 50%,” he said.
In the interview, Dr. Pappo was also asked if pediatricians are vigilant for melanoma during office visits and if such checks should be integrated into well-child visits. He said that if parents spot a mole on a child, they should report its existence to the pediatrician. “The classical ABCDEs of melanoma that we see in adults are not exactly the same in children. Routine visits with physical exams are routinely recommended by the American Academy of Pediatrics. I emphasize discussion of preventive measures at each office visit, especially during the summer when families are going to the beach. Physicians should listen to parents. If there is a mole that the parent is concerned about that has changed in size or has had bleeding or ulceration, then listen to them and refer them to a dermatologist. In pediatrics, the vast majority of cases are identified by parents bringing up their concern to their primary care physician,” Dr. Pappo said.
According to Dr. Pappo, if melanoma is caught early, the survival probabilities are very high, reducing the risks of tumor spread and reducing the need for invasive surgery. However, if caught late, these probabilities diminish. Dr. Pappo highlighted that when a melanoma is diagnosed at the pediatrician’s office, the family should ask to know the specific type of melanoma found on the child. This is especially important in the case of a spitzoid melanoma, as the therapeutic options differ from those used to treat conventional melanoma. “At St. Jude, for example, if a spitzoid melanoma has spread to the lymph nodes, we are not being as aggressive anymore in terms of complex surgeries and giving interferon as we have in the past because we have learned that these tumors have a much more indolent and benign clinical behavior. We still do not know why this is so, but we at least know this and we are tailoring our therapies based upon the type of melanoma we are seeing. We do not treat any melanomas the same as we did 10 years ago,” Dr. Pappo concluded.