Increased risk of skin cancer in 1851 long-term retinoblastoma survivors.

Overview

Hereditary retinoblastoma patients are at risk for developing cutaneous melanoma, but little is known about the role of sun exposure or other factors, and incidence of non-melanoma skin cancer (NMSC) is poorly understood. We investigated the incidence of melanoma and NMSC in a cohort of 1851 white, long-term retinoblastoma survivors (1020 hereditary and 831 nonhereditary) diagnosed from 1914-2006. During follow-up through 2016, 33 hereditary and 7 nonhereditary survivors developed melanoma, and 26 hereditary and 9 nonhereditary survivors developed NMSC. Most NMSC were on the head/neck whereas melanomas were more broadly distributed with patterns similar to melanoma-prone families. For both outcomes, median age at diagnosis was ∼20 years younger among hereditary than nonhereditary survivors. Fifty years following retinoblastoma diagnosis, the cumulative incidence in hereditary survivors was 4.5% for melanoma and 3.7% for NMSC; for nonhereditary survivors, it was 0.7% and 1.5%, respectively. Sun sensitivity and phenotypic characteristics generally did not vary by skin cancer status. Hereditary retinoblastoma survivors have an increased risk for melanoma and NMSC that occurred earlier compared with nonhereditary survivors, likely reflecting genetic factors. These findings among white retinoblastoma survivors support consensus-based recommendations for skin cancer screening and sun protection starting at young ages and continuing long-term.