Trends in paediatric cancer survival in Canada, 1992 to 2017.

BACKGROUND While impressive gains in childhood cancer survival have been reported both in Canada and internationally, it has been almost 15 years since the last comprehensive evaluation of Canadian data. DATA AND METHODS Data are from the population-based Canadian Cancer Registry, record-linked to the Canadian Vital Statistics Death database. Children aged 0 to 14 diagnosed with new primary malignant cancers from 1992 to 2017 in Canada except Quebec were included. Overall survival was measured using observed survival proportions (OSPs). Estimates for the 2013-to-2017 period were predicted using the period method; otherwise, the cohort method was used. RESULTS For the 2013-to-2017 period, five-year OSPs were at least 90% for 10 of 24 individual cancer groups or subgroups reported. Survival was highest for thyroid carcinomas (100%) and Hodgkin lymphomas (99%) and lowest for other gliomas (42%). A significant increase in the five-year OSP from the 1992-to-1996 period (77%) to the 2013-to-2017 period (84%) was observed for all childhood cancers combined, but not since the 2003-to-2007 period. The greatest increase was for chronic myeloproliferative diseases (35.4 percentage points); for lymphoid leukemias, survival increased from 85% to 93%. Survival was relatively poor at baseline for hepatic tumours, malignant bone tumours, and soft tissue and other extraosseous sarcomas, and it remained virtually unchanged. Once children survived five years, the probability of surviving another five years exceeded 95% across most diagnoses. DISCUSSION Significant improvements in both short- and long-term paediatric cancer survival have been made in Canada since the early to mid-1990s. These findings are clinically meaningful and are likely to be reassuring to families.