Melanoma in individuals with neurofibromatosis type 1: a retrospective study

Neurofibromatosis type 1 (NF1) is a cancer syndrome associated with many different cancer types. There are limited studies examining melanoma risk in this population.

To identify melanoma cases in NF1 patients and compare melanoma incidence rates relative to a general population sample.

A retrospective single institution case review of 857 NF1 patients (seen from 7/1997 to 7/2017) was conducted. We calculated age- and calendar period-adjusted standardized incidence ratios (SIRs) for white patients >20 years old overall (N=282) and for females (N=156) at their last visit date. We obtained general population melanoma reference rates from the Surveillance, Epidemiology, and End Results (SEER) 9 database.

Among 857 patients, 52.2% were female, 54% were <20 (mean±sd=10.9±4.6) years old, and 46% were >20 (40.4±14.9) years old at their last visit date. One white female patient had a malignant melanoma diagnosed at 47 years old. The adjusted SIR was 0.97 (95% CI 0.05-4.78) overall (N=282) and 1.62 (95% CI 0.08-7.98) for females (N=156).

We did not find statistical evidence for an increased melanoma risk in adults with NF1. However, additional large studies are warranted to clarify whether melanoma risk is increased in NF1 patients.