Long‐term non‐cancer mortality in pediatric and young adult cancer survivors in Finland

Abstract

Excess late mortality has been reported among pediatric cancer survivors, but there is a need to further establish risk profiles for non-cancer death and to examine cause-specific mortality among survivors of young adult cancers. In a nationwide record linkage study in Finland, we identified 9,245 5-year cancer survivors diagnosed before age 35 and treated between 1966 and 1999, and followed them for mortality endpoints from 1971 to 2008. Standardized mortality ratios (SMRs) and 95% confidence intervals (95% CIs) were calculated to compare the observed number of deaths with those expected in the general Finnish population. Primary endpoints included death from cardiovascular and respiratory diseases; death from malignant diseases was excluded. Non-malignant disease mortality in the cohort was 90% higher (SMR=1.9, 95% CI: 1.7-2.2) than expected, with SMRs for circulatory and respiratory disease similarly elevated (SMR=1.9, 95% CI: 1.5-2.3 and SMR=2.3, 95% CI: 1.3-3.8, respectively). Important differences were noted amongst patient subgroups, with risk greatest for survivors of central nervous system (CNS) cancer, Hodgkin lymphoma (HL), and non-Hodgkin lymphoma (NHL). The SMR's for circulatory disease were 6.6 (95% CI: 4.8-8.9) for HL and 4.8 (95% CI: 2.6-8.1) for NHL for the entire population; but these risks remained elevated for survivors diagnosed between 15 and 34 years of age. Previous studies have shown that there is an elevated risk of non-cancer mortality in childhood cancer survivors; this is one of the first studies that show an increase in cardiovascular and respiratory mortality in long-term survivors of adolescent and young adult cancers.