Incidence and outcomes of pediatric extremity melanoma: A propensity score matched SEER study.

BACKGROUND: There is a paucity of literature on treatment of melanoma in children with surgical management extrapolated from adult experience. The incidence and clinical outcomes of pediatric extremity melanoma were studied.

METHODS: SEER registry was analyzed between 1973 and 2010 for patients <20years old with extremity melanoma. Multivariate and propensity-score matched analyses were performed to identify independent predictors of survival.

RESULTS: Overall, 917 patients were identified with an age-adjusted incidence of 0.2/100,000 persons, annual percent change 0.96. Most had localized disease (77%), histology revealing melanoma-not otherwise specified (52%). Surgical procedures performed included wide local excision (50%), excisional biopsy (32%), lymphadenectomy (LA) (28%), and sentinel lymph node biopsy (SLNB) (15%). Overall, 30-year disease specific mortality was 7% with lower survival for extremity melanoma (90%), males (89%), nodular histology (69%), and distant disease (36%) (all P<0.05). Post-treatment multivariate analysis revealed localized disease (HR 9.76; P=0.006) as an independent prognosticator of survival; earlier diagnostic years 1988-1999 (HR 2.606; P=0.017) were a negative prognosticator of survival. Propensity-score matched analysis found no difference in survival between SLNB/LA vs no sampling for regional/distant disease.

CONCLUSIONS: Pediatric extremity melanoma in SEER demonstrate no survival advantage between children undergoing sampling procedures vs no sampling for regional/distant disease.

TYPE OF STUDY: Retrospective, prognostic study.

LEVEL OF EVIDENCE: III.