Long-Term Survival in Children and Adolescents with Solid Tumors in the State of São Paulo, Brazil (2000-2023): A Hospital-Based Population Epidemiological Study

Objective: This study evaluates the survival of children and adolescents diagnosed with the five most prevalent malignant solid neoplasms in the 0-19 age group between 2000 and 2023 in the state of São Paulo, Brazil. Methods: A population-based epidemiological study with a descriptive-analytical design was conducted using data from 77 hospitals registered at the Fundação Oncocentro de São Paulo, following the International Classification of Childhood Cancer (ICCC). The time intervals between consultation, diagnosis, and treatment initiation were analyzed. Survival was estimated using the Peto-Peto method, while the Benjamin-Hochberg method was applied to control type I errors in the statistical analysis when identifying associations between patient characteristics and clinical outcomes. Results: A total of 11,067 patients were included, of whom 53.5% were male, all diagnosed through microscopic confirmation. The most frequent neoplasms were central nervous system tumors (34.3%), bone tumors (21.1%), soft tissue tumors (18.6%), germ cell tumors (14.2%), and retinoblastomas (11.9%). The most common treatment was surgery combined with chemotherapy (26.5%), followed by surgery alone (20.5%) and chemotherapy alone (15.6%). The mean time between consultation and diagnosis was 22.94 ± 69.93 days, with statistically significant differences between treatment types and recurrences (p < 0.05). The mean time from diagnosis to treatment initiation was 25.46 ± 39.71 days, showing statistical variation between sexes in germ cell tumors (p = 0.0054), but no significant differences for treatments of these tumors (p = 0.0793) or retinoblastoma recurrences (p = 0.0697). Conclusions: Survival curves indicate variations among pediatric solid tumor subtypes, highlighting disparities in diagnostic and treatment times, even in a state with a high density of specialized healthcare services. These findings emphasize the need for strategies to reduce delays and improve access, directly impacting patient survival.