Melanoma in Children Appears Different Than Adult Disease
Survival rate in young kids is higher, small study finds
FRIDAY, March 11, 2005 (HealthDay News) -- A small study of 33 Italian children with melanoma found those children who were under 10 at the time of diagnosis had higher survival rates than those who were older when they were diagnosed.
The researchers also found the disease sometimes appears differently in children compared to adults.
"Our findings give the impression that melanoma behaves differently in the younger age group," report the researchers, from the Pediatric Oncology Unit at the Istituto Nazionale per lo Studio e la Cura dei Turmori in Milan.
Other health experts acknowledge that some of the findings are interesting, but caution against jumping to conclusions on the strength of such a small study.
"There are some patterns of note -- it does raise the possibility that there may be something different biologically in the melanomas of children -- but the study is very small, and there is very little one can say," said Kathleen Egan, an associate professor of medicine at Vanderbilt University School of Medicine in Nashville.
The study appears in the March issue of Pediatrics.
For the study, the researchers analyzed data on the 33 children, who had been diagnosed with the skin cancer before the age of 14. Melanoma is the rarest, but most deadly, of the three skin cancers, with about 54,000 new cases diagnosed each year in the United States, according to the National Cancer Institute. While the prevalence of melanoma is increasing -- rates have doubled over the last 30 years -- it's still rare in children.
The severity of the disease among the 33 children ranged from cancerous skin lesions, to cancer that had spread beyond the initial tumor. Most of the lesions were found on the legs. Surgery to remove the cancer was the primary treatment.
With a median follow-up of 11 years, 60 percent of the children experienced five-year-event-free survival, and overall survival was 70 percent. Divided by age, however, those under 10 years at the time of diagnosis experienced a 90 percent, event-free survival rate compared to a 47 percent event-free survival rate for those who were older when they were diagnosed.
This was true even though the initial cancer diagnosis seemed worse in the younger children as measured by the thickness of their lesions. The researchers suggest that the reason younger children had more serious cancer initially is because the disease is so rare in young children that doctors might not look for it.
Also of note, the researchers said, was that the lesions found in the children were somewhat different than those typically found in adults. There were more amelanotic lesions, which are lesions that lack melanin -- the natural substance that gives color to hair, skin and the iris of the eye -- and the lesions were generally thicker than those in adults. Also, most of the lesions were found on the children's legs, which is not the case with adult melanoma, the researchers said.
"It is generally assumed that childhood melanoma behaves biologically like its adult counterpart, but our results make us wonder whether this is really so," the researchers wrote.
Egan said that, due to the small number of children in the study, there's a risk the findings might be unique to that group of kids, and may not apply to children in general. But, she added, it would be hard to find a larger group because the disease is so rare in children.
The findings are useful because they can alert parents to the fact that children can get melanoma, and it's often diagnosed, Egan said.
"The last thing anyone wants to think about is looking at cancer in an 8-year-old, and there is also a natural abhorrence to doing a biopsy on a small child," Egan said. So if parents are concerned, they should take their child to a dermatologist who specializes in melanoma and can spot any suspicious lesions early, she said.
To learn more about melanoma, visit the American Academy of Dermatology.