Whilst men with testicular cancer have a twofold increase in second malignant neoplasms (SMNs), the risk in children with germ cell tumors (GCTs) is not fully quantified. SMNs in children treated for GCTs was assessed in the Malignant Germ Cell Tumor International Consortium data commons (n = 917). Thirteen SMNs were identified with median follow-up of only 5.9 years. Assigning cause is nuanced because GCT-related SMNs can either be treatment related, second primary malignancies from a common primordial germ cell progenitor, or somatic malignant transformation of the original GCT. Longer follow-up of children with GCT is needed to ascertain risk and understand causation.
Pediatric blood & cancer. 2026 Mar 15 [Epub ahead of print]
Priya Mahajan, Mark Krailo, Negar Fallahazad, Michelle Nuno, Brice Fresneau, Sara Stoneham, A Lindsay Frazier
Department of Pediatrics, Section of Hematology/Oncology, Seattle Children's Hospital, University of Washington, Seattle, Washington, USA., University of Southern California Keck School of Medicine, Los Angeles, California, USA., Statistics and Data Center, Children's Oncology Group, Monrovia, California, USA., Department of Children and Adolescents Oncology, Gustave Roussy, Université Paris-Saclay, Villejuif, France., Children and Young Peoples Cancer Services, University College London Hospital, London, UK., Dana Farber/Boston Children's Cancer and Blood Disorders Center, Boston, Massachusetts, USA.