Temporal trends in cause-specific late mortality among 5-year survivors of childhood cancer

Abstract

Purpose: 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.

Patients and methods: 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.

Results: 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.

Conclusion: 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.

Fig 1.

Cumulative incidence of all-cause late mortality, recurrence/progression-related late mortality, and nonrecurrence/nonexternal-cause late mortality for all 5-year survivors and for 5-year survivors of acute lymphoblastic leukemia, Hodgkin's lymphoma, or Ewing sarcoma.

Fig 2.

Cumulative all-cause and cause-specific mortality by race/ethnicity; non-Hispanic white (n = 18,365), non-Hispanic black (n = 2,331), non-Hispanic Asian/Pacific Islander (n = 1,673), and Hispanic (n = 3,818).

Fig A1.

Cumulative all-cause and cause-specific mortality by sex.