PURPOSE: Infants with cancer are rare and face unique challenges. Our study aims to describe the incidence of infantile cancers in Canada and to compare treatment-related mortality (TRM) and their outcomes with those of older children.
METHODS: We conducted a retrospective cohort study using the Cancer in Young People in Canada database, including all infants (0 to <1 year old) with newly diagnosed cancer from 2001 to 2020. Population-based data were used to estimate annual cancer incidence. Cox proportional hazards models were used to compare TRM, event-free survival (EFS) and overall survival (OS) between (1) neonates (<30 days old) and older infants (≥30 days to <1 year old, (2) younger (<6 months) and older infants (≥ 6 months), and (3) all infants with older children (≥1 to ≤10 years old).
RESULTS: A total of 2256 infants were included. The incidence was 30.8 per 100,000 infant-years, and this incidence increased with an annual percent change of 1.6%, p < 0.001. Neonates had significantly higher TRM (6.1 vs. 3.6%, HR 2.76, p < 0.001) as well as infants younger than 6 months (5.2 vs. 2.7%, HR 2.05, p < 0.001). Compared with older children, infants experienced higher risk of TRM (4.1 vs. 2.1%, HR 2.45, p < 0.001) and had inferior 5-year EFS (66.2 vs. 68.6%, HR 1.27, p < 0.001) and OS (77.5 vs. 78.6%, HR 1.22, p < 0.001).
CONCLUSION: The annual incidence of infantile cancers in Canada has increased and their outcomes are significantly worse than those of older children, as they face a higher risk of TRM, particularly in younger infants. PRÉCIS: The incidence of cancer in infants has increased significantly in Canada between 2001 and 2020 and their outcomes are significantly lower than those of older children, being at greater risk of TRM.