Are pediatric central nervous system tumors on the rise in France? A population-based 21-year retrospective study

Central nervous system (CNS) tumors are the second most common type of cancer in children. Their apparent rise in incidence represents a potential public health concern, as it could reflect increased exposure to environmental risk factors unless the trend is primarily driven by changes in classification systems or diagnostic practices.

This study included 10,074 children aged 0-14 years diagnosed with a primary CNS tumor between 2000 and 2020 in the French National Childhood Cancer Registry. CNS tumors were reclassified according to the fifth edition of the World Health Organization Classification. Joinpoint regression analysis was used to estimate annual changes in incidence.

The annual age-standardized incidence rate (ASR) of CNS tumors was 42.1 per million. From 2000-2020, the incidence increased by an average of 0.93% per year [95%CI: + 0.50;+ 1.38], rising from 38.3 to 46.2 cases per million. This upward trend affected both sexes and was particularly evident among children aged 10-14 years. The most marked increases were observed for optic pathway gliomas (+2.15% annually), atypical teratoid/rhabdoid tumors (ATRT, +2.32%), pituitary adenomas (+1.28%), and malignant mesenchymal tumors (+6.53%). The fluctuating incidence of gangliogliomas and glioblastomas largely reflected reclassification within the glial tumor categories.

Most of the observed variations appear to result from improved diagnostic practices in at-risk children (optic pathway gliomas), more accurate tumor categorization (mesenchymal tumors), or enhanced case registration (pituitary adenomas). Only ATRTs show evidence of a true increase in incidence, as diagnostic criteria have remained relatively stable over the past 20 years.''.