Burden of early-onset cancers in Hungary: Nationwide trends in incidence and mortality.

e22616 Background: Cancers diagnosed before 50 years of age (“early-onset” cancers) are increasingly recognized as a distinct epidemiologic and clinical entity. However, population-level data describing their contribution to cancer burden in Central and Eastern Europe remain limited. We evaluated the incidence and mortality of major early-onset cancers in Hungary using nationwide administrative data. Methods: We analyzed nationwide oncology records from the Hungarian National Health Insurance Fund (NEAK), covering the entire population, for major cancer types including colorectal (C18), breast (C50), lung (C34), testicular (C62), melanoma (C43), and gastric (C16) cancers. Annual incidence, mortality, and prevalence were calculated using national population denominators. Analyses were stratified by sex, cancer type, and early-onset status (diagnosis < 50 years). Temporal patterns were assessed by comparing earlier baseline periods with more recent years, and findings were cross-validated against publicly available national cancer registry statistics. Results: Early-onset cancers constituted a substantial proportion of incident cases, with marked heterogeneity across tumor types. Among newly diagnosed cases, cancers diagnosed before age 50 accounted for 18.9% of breast cancer, 74.9% of testicular cancer, 22.7% of melanoma, 3.6% of lung cancer, and 6.3% of gastric cancer. Early-onset disease also contributed meaningfully to cancer-related mortality: 5.7% of breast cancer deaths, 32.0% of testicular cancer deaths, 4.8% of melanoma deaths, 2.0% of lung cancer deaths, and 4.3% of gastric cancer deaths occurred in patients younger than 50 years. Trends over time demonstrated variable patterns by cancer type, indicating differential contributions of early-onset disease to national cancer burden. Conclusions: Nationwide administrative data from Hungary demonstrate that cancers diagnosed before age 50 contribute a non-negligible proportion of both incident cases and cancer-related deaths across multiple tumor types. The observed heterogeneity underscores the need for tumor-specific evaluation of early-onset cancer trends and supports further investigation into tailored prevention, screening, and survivorship strategies for younger populations.