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Changes in nevi were poor predictors of melanoma in children

Monitoring changes in nevi may not be a useful approach to melanoma detection in children and may lead to unnecessary biopsies in this population, according to recent study findings.

In the study, researchers utilized data from the Pinkus Dermatopathology Laboratory database and the HealthCore Integrated Research Database (HIRD) to estimate the number of nevus biopsies in patients 19 years or younger in the U.S. between 2009 and 2013. The researchers classified surgical specimens from the dermatopathology database based on histopathologic diagnosis of one of the following: melanoma, nevi (acquired, congenital, blue, Spitz nevi) or all other diagnoses. These specimens were further categorized by age categories (ages 0-9, 10-14 or 15-19 years).

From the HIRD, the researchers included all patients with a minimum of one CPT code for excision, shave removal or biopsy. They then applied biopsy rates from the HIRD population to 2010 U.S. Census data to estimate age- and gender-specific biopsy counts extrapolated to the U.S. population. Age- and gender-specific melanoma incidence rates from the Surveillance, Epidemiology and End Results (SEER) database were then applied to the extrapolated biopsy rates to determine the predicted number of melanomas. To test the accuracy and public health relevance of biopsies, the researchers calculated the number of nevi needed to biopsy (NNB) to detect one melanoma.

The researchers found that of the 18,601 surgical specimens identified in the dermatopathology database between 2009 and 2013, there were 16 melanomas (0.09%), 10,800 nevi (58,1%) and 7,785 other diagnoses (41.9%), which led to an overall NNB of 676. A total of 133,431 biopsies for nevi were identified from the HIRD during the course of the study, and based on age-and gender-specific SEER cancer rates, there were an estimated 136 melanomas. This resulted in an NNB of 982.

Based on HIRD and 2010 U.S, Census Data, the researchers estimated that during the study period, 2,007,423 biopsies of nevi were performed on patients 19 years or younger in the U.S., and there were 1,940 melanomas. This led to an overall NNB of 1,035.

The researchers concluded that the evolution of nevi is common in childhood, therefore making change in nevi a poor predictor of melanoma in individuals younger than 18 years of age, especially when the actual prevalence of melanoma in this age group is so low.

Disclosure: This study was supported in part by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under award R01-AR-49342.