Temporal Trends in Cause-Specific Late Mortality Among 5-Year Survivors of Childhood Cancer

Abstract

Five-year survival rates for childhood cancer have improved over the past four decades. However, it is unknown whether changes in primary cancer therapy have improved rates of long-term (> 5 years from diagnosis) durable remissions and reduced treatment-related deaths. We investigated changes in patterns of late mortality over time and cause-specific attribution of late-mortality among 5-year survivors. Using data from the Surveillance, Epidemiology and End Results (SEER) population-based registry, we assessed all-cause and cause-specific (recurrence/progression of primary disease, external cause, and nonrecurrence/nonexternal cause) late mortality during four consecutive time periods from 1974 through 2000 among 26,643 5-year survivors of childhood cancer. All-cause late mortality improved during more recent eras, dropping from 7.1% (95% CI, 6.4% to 7.8%) among children diagnosed during 1974 to 1980 to 3.9% (95% CI, 3.3% to 4.4%) among children diagnosed during 1995 to 2000 (P < .001), largely because of reduced mortality from recurrence or progression. While there was no significant reduction in mortality attributable to other health conditions (including treatment-related health conditions), analysis controlling for demographic characteristics identified a trend toward reduced risk during more recent eras (P = .007). Disparity by race/ethnicity was identified, with higher mortality among non-Hispanic blacks than among non-Hispanic whites for all-cause and nonrecurrence/nonexternal -cause late mortality. While overall patterns of mortality from other health conditions do not differ over time, adjustment for demographic characteristics provides evidence that risk of treatment-related mortality may be lower in more recent eras. Disparities in health care utilization among survivors should be explored.