Population-based retrospective cohort study of stage at diagnosis and international survival variation in childhood tumors

Understanding the reasons for variations in population-level survival differences in childhood cancer is important to guide improvement efforts. Collaboration between population-based cancer registries to apply the international consensus Toronto guidelines to record tumor stage at diagnosis is a key first step. The International Benchmarking of Childhood Cancer Survival by Stage (BENCHISTA) tested whether survival probablities by tumor stage vary internationally, using 6 childhood solid tumors (neuroblastoma, Wilms tumor, medulloblastoma, osteosarcoma, Ewing sarcoma of bone, and rhabdomyosarcoma) as exemplars. In this retrospective cohort study with 9883 cases from 73 cancer registries in 27 countries, 3-year overall survival decreased with higher tumor stage at diagnosis. Regional survival differences were partly associated with stage variation, notably in neuroblastoma, rhabdomyosarcoma, and medulloblastoma, but not in Ewing sarcoma. The authors conclude that the study highlights geographic disparities in survival, stressing the need for early diagnosis, precise staging, and stronger collaboration between clinicians and cancer registries to understand survival gaps.