Childhood Lymphoproliferative Disorders with Inborn Errors of Immunity from the Perspective of Oncology

Background: Malignancy is an important issue for immunodeficiency patients and management could be challenging. This study aims to review inborn errors of immunity (IEI) patients with lymphoprolife-rative disorders. Materials and Methods: Age at diagnosis, gender, type of immunodeficiency, tumor type and loca-tion, Ebstein-Barr virus (EBV) status, comorbidity, treatment schemes for malignancy, and follow-up time were evaluated in 12 patients between 2007-2023, retrospectively. Results: Ten of twelve patients (83,3%) were male. Median age was 8 years. In terms of immunodefi-ciency type, 11 had a definitive diagnosis of IEI, 5 of which had DNA repair defects. One had been diagnosed with DOCK8 disorder without any history of frequent and/or severe infections previously. Nine patients (75%) were diagnosed with IEI after malignancy. Lymphoma was the leading lymphopro-liferative disorder (n=10) and most of them were diffuse large B-cell lymphoma (n=4). Lymphoid nodal involvement was the prominent location (n=9), but primary central nervous system and gastric mucosal involvement were unusual. Three patients were EBV positive. All patients were treated with several chemotherapy regimens. Median follow-up time was 32,6 months. Seven patients (58.3%) died because of infection or malignancy or other causes. All other patients are still under follow-up with disease-free. The 5-year event-free survival was 38.9% and overall survival was 51.9%. Conclusions: All patients with IEI should be monitored for malignancy. Furthermore patients with unusual findings of malignancy shouldalso be examined for IEI.