Trends in late mortality among adolescent and young adult (AYA) cancer survivors

Authors: Anderson C, Nichols HB

Category: Survivorship & Health Outcomes/Comparative Effectiveness Research
Conference Year: 2020

Abstract Body:
Purpose of the study: Over the past several decades, treatment of cancer in adolescents and young adults (AYAs, age 15-39 years) has evolved significantly, leading to steady improvements in estimated five-year survival at diagnosis. However, the impact on late mortality in this population is largely unexamined. Therefore the purpose of these analyses was to investigate temporal trends in mortality among five-year AYA cancer survivors. Methods: The Surveillance, Epidemiology, and End Results (SEER) database was used to identify AYAs who were diagnosed with a first primary cancer between 1975 and 2011 and survived at least five years beyond diagnosis. Survival months were accrued from five years post-diagnosis until death or end of 2016, whichever occurred first. Cumulative mortality from all causes, cancer, and noncancer/nonexternal causes (i.e. excluding accidents, suicide, homicide) was estimated according to diagnosis era (1975-1984, 1985-1994, 1995-2004, 2005-2011). Estimates for cancer-specific and noncancer/nonexternal mortality accounted for deaths from all other causes as competing risks. Results: Among 282,969 five-year survivors of AYA cancer, five-year mortality (i.e. from 5 through 10 years post- diagnosis) from all causes decreased from 8.3% (95% CI: 8.0%-8.6%) among those diagnosed in 1975-1984 to 5.4% (95% CI: 5.3%-5.6%) among those diagnosed in 2005-2011. This was largely explained by decreases in cancer-specific mortality (7.0% to 4.3%) between these periods. However, for specific cancer types, including colorectal, bone, cervical/uterine, soft tissue sarcomas, and bladder, cumulative mortality curves demonstrated little improvement in cancer-specific mortality over time. Reductions in late mortality from noncancer/nonexternal causes over time were apparent for Hodgkin lymphoma and trachea, lung, and bronchus cancers; some evidence also suggested improvements for leukemia, central nervous system tumors, and head and neck cancers. Conclusions: Over the past four decades, all-cause and cancer-specific mortality have decreased among five-year AYA cancer survivors overall, but several cancer types have not shared in these improvements.

Keywords: Adolescents and young adults; trends; mortality