Central Nervous System Tumors Among Infants in Canada: A Report From CYP‐C

BACKGROUND: Central nervous system (CNS) tumors in infants are rare, pose unique clinical challenges, and lack large-scale evidence-based data to guide management. This study seeks to describe CNS tumors in Canadian infants and to compare their outcomes with those of older children. METHODS: We conducted a retrospective cohort study using the Cancer in Young People in Canada (CYP-C) database, a population-based childhood cancer surveillance program in Canada. The study included all children under 10 years with newly diagnosed CNS tumors between 2001 and 2020. Cox proportional hazards models were employed to compare event-free survival (EFS) and overall survival (OS) between infants (<1 year) and older children (1 to ≤10 years) in the overall cohort and stratified by CNS tumor subtype. RESULTS: A total of 3599 children with CNS tumors were included in the study, of whom 304 infants (8.4%) comprised the cohort. The median age of infants with CNS tumors was 6.1 months (IQR: 2.9-9.5). The most common CNS tumor subtypes in infants were gliomas and glioneuronal tumors (n = 157, 51.7%, including 95 infants [31.3%] with low-grade and 36 infants [11.8%] with high-grade gliomas), followed by atypical teratoid/rhabdoid tumors (n = 45, 14.8%), choroid plexus tumors (n = 33, 10.8%), ependymomas (n = 31, n = 10.2%), and medulloblastomas (n = 15, 5.3%). Infants had significantly more metastatic disease compared to older children (15.0% vs. 8.7%; p < 0.001). Treatment approaches differed significantly between infants and older children, with infants receiving radiotherapy far less frequently (6.9% vs. 22.2%; p < 0.001). Compared with older children, infants had worse 5-year EFS (43.9% [95% CI: 35.9-50.1] vs. 57.7% [95% CI: 55.6-59.8]; p < 0.001) and worse 5-year OS (52.8% [95% CI: 45.3-59.8] vs. 66.7% [95% CI: 64.7-68.7]; p < 0.001). In multivariable analyses adjusting for CNS tumor subtype and metastatic status, infants had significantly poorer EFS (adjusted HR [aHR] 1.55, 95% CI: 1.29-1.87; p < 0.001) and OS (aHR 1.64, 95% CI: 1.34-2.01; p < 0.011). Stratified by tumor subtypes, infants with low-grade gliomas (OS HR 3.41, 95% CI: 1.76-6.63; p < 0.001), medulloblastomas (OS HR 2.47, 95% CI: 1.15-5.30; p = 0.02), and atypical teratoid/rhabdoid tumors (OS HR 2.69, 95% CI: 1.71-4.23; p < 0.001) demonstrated significantly inferior outcomes compared to older children. CONCLUSION: Infants account for 8.4% of all children under 10 years with CNS tumors in Canada. Their outcomes are significantly worse than those of older children, particularly among patients with low-grade gliomas, medulloblastomas, and atypical teratoid/rhabdoid tumors.