In a Childhood Cancer Survivor Study analysis reported in the Journal of Clinical Oncology, Rotz et al found that adult survivors of childhood cancers had a twofold increased risk of developing melanoma compared with the general population. Additionally, those with an invasive melanoma had a more than twofold risk of death.
Study Details
The study assessed incidence, risk factors, and outcomes of melanoma among adult survivors of childhood cancers in the Childhood Cancer Survivor Study cohort. Cumulative incidence and standardized incidence ratios were calculated, with multivariate modeling used to identify risk factors. Radiation exposure to seven body regions and melanoma status for eight regions per survivor were integrated into the model.
Key Findings
Among 25,716 adult survivors of childhood cancer—with a median follow-up of 26 years and a median attained age of 33 years—177 melanomas developed in 160 survivors, including 110 invasive, 62 in situ cutaneous, and 5 ocular melanomas.
The 40-year cumulative incidence of melanoma was 1.1% (95% confidence interval [CI] = 0.9%–1.4%) among all survivors and 1.5% (95% CI = 1.0%–2.1%) among those receiving a cumulative radiation dose of at least 40 Gy. Compared with the general population, the standardized incidence ratio for invasive skin or ocular melanoma was 2.0 (95% CI = 1.6–2.4).
A cumulative radiation dose of at least 40 Gy to corresponding body region(s) of the melanoma (hazard ratio [HR] = 2.0, 95% CI = 1.1–3.7), cumulative cyclophosphamide equivalent dose of at least 20,000 mg/m2 (HR = 1.9, 95% CI = 1.1–3.6), and bleomycin exposure (HR = 2.2, 95% CI = 1.2–4.1) were associated with a significantly increased risk of cutaneous melanoma. Invasive melanoma at any site was associated with an increased risk of death (HR = 2.4, 95% CI = 1.7–3.3).
The investigators concluded: “Childhood cancer survivors have more than a twofold increased risk of melanoma compared with the general population, and those with an invasive melanoma have more than a twofold risk of death. High-dose radiation, alkylating agent exposure, and bleomycin are important risk factors for melanoma and should be considered in future patient guidance and screening.”
Seth J. Rotz, MD, of the Department of Pediatric Hematology, Oncology, and Bone Marrow Transplantation, Cleveland Clinic Children’s Hospital, is the corresponding author of the Journal of Clinical Oncology article.
Disclosure: The study was supported by the National Cancer Institute, National Center for Advancing Translational Sciences, American Lebanese Syrian Associated Charities, and others. For full disclosures of the study authors, visit ascopubs.org.