Disparities in survival improvement for U.S. childhood and adolescent cancer between 1995 and 2019: An analysis of population-based data

Background: Although treatment advances have increased childhood and adolescent cancer survival, whether patient subgroups have benefited equally from these improvements is unclear.

Methods: Data on 42,865 malignant primary cancers diagnosed between 1995 and 2019 in individuals ≤ 19 years were obtained from 12 Surveillance, Epidemiology, and End Results registries. Hazard ratios (HRs) and 95 % confidence intervals (CIs) for cancer-specific mortality by age group (0-14 and 15-19 years), sex, and race/ethnicity were estimated using flexible parametric models with a restricted cubic spline function in each of the periods: 2000-2004, 2005-2009, 2010-2014 and 2015-2019, versus 1995-1999. Interactions between diagnosis period and age group (children 0-14 and adolescents 15-19 years at diagnosis), sex, and race/ethnicity were assessed using likelihood ratio tests. Five-year cancer-specific survival rates for each diagnosis period were further predicted.

Results: Compared with the 1995-1999 cohort, the risk of dying from all cancers combined decreased in subgroups defined by age, sex and race/ethnicity with HRs ranging from 0.50 to 0.68 for the 2015-2019 comparison. HRs were more variable by cancer subtype. There were no statistically significant interactions by age group (P_interaction=0.05) or sex (P_interaction=0.71). Despite non-significant differences in cancer-specific survival improvement across different races and ethnicities (P_interaction=0.33) over the study period, minorities consistently experienced inferior survival compared with non-Hispanic Whites.

Conclusions: The substantial improvements in cancer-specific survival for childhood and adolescent cancer did not differ significantly by different age, sex, and race/ethnicity groups. However, persistent gaps in survival between minorities and non-Hispanic Whites are noteworthy.