Survival of Adolescents and Young Adults with Prevalent Poor-Prognosis Metastatic Cancers: A Population-Based Study of Contemporary Patterns and Their Implications.

BACKGROUND:Although survival has improved dramatically for most adolescents and young adults (AYA; 15-39 years old) with cancer, it remains poor for those presenting with metastatic disease. To better characterize this subset, we conducted a landscape survival comparison with older adults (40-79 years). METHODS:Using Surveillance, Epidemiology, and End Results Program data from 2000 to 2016, we examined incident cases of poor-prognosis metastatic cancers (5-year survival < 50%) among AYAs (n = 11,518) and older adults (n = 345,681) and compared cause-specific survival by sociodemographic characteristics (race/ethnicity, sex, and socioeconomic status). Adjusted HRs (aHR) for death from metastatic disease [95% confidence intervals (95% CI)] were compared between AYAs and older adults (Pint). RESULTS:AYAs had significantly better survival than older adults for every cancer site except kidney, where it was equivalent (range of aHRs = 0.91; 95% CI, 0.82-1.02 for kidney cancer to aHR = 0.33; 95% CI, 0.26-0.42 for rhabdomyosarcoma). Compared with their older adult counterparts, greater survival disparities existed for AYAs who were non-Hispanic Black with uterine cancer (aHR = 2.20; 95% CI, 1.25-3.86 versus aHR = 1.40; 95% CI, 1.28-1.54; Pint = 0.049) and kidney cancer (aHR = 1.51; 95% CI, 1.15-1.98 versus aHR = 1.10; 95% CI, 1.03-1.17; Pint = 0.04); non-Hispanic Asian/Pacific Islanders with ovarian cancer (aHR = 1.47; 95% CI, 1.12-1.93 versus aHR = 0.89; 95% CI, 0.84-0.95; Pint<0.001); and males with colorectal cancer (aHR = 1.21; 95% CI, 1.10-1.32 versus aHR = 1.08; 95% CI, 1.06-1.10; Pint = 0.045). CONCLUSIONS:AYAs diagnosed with these metastatic cancers have better survival than older adults, but outcomes remain dismal. IMPACT:Overcoming the impact of metastasis in these cancers is necessary for continuing progress in AYA oncology. Sociodemographic disparities affecting AYAs within kidney, uterine, ovarian, and colorectal cancer could indicate plausible effects of biology, environment, and/or access and should be explored.