Associations between geographic residence and US adolescent and young adult cancer stage and survival.

BACKGROUND Multiple studies have indicated that place of residence can influence cancer survival; however, few studies have specifically focused on geographic factors and outcomes in adolescents and young adults (AYAs) with cancer. The objective of this study was to evaluate evidence for geographic disparities in cancer diagnosis stage and overall survival in AYAs and to examine whether stage mediated survival associations. METHODS National Cancer Database data on AYAs aged 15 to 39 years who were diagnosed with cancer from 2010 to 2014 were obtained. Residence in Metropolitan (metro), urban, or rural counties at the time of diagnosis was defined using Rural-Urban Continuum Codes. Distance between the patient's residence and the reporting hospital was classified as short (≤2.5 miles), intermediate (>12.5 to <50 miles), or long (≥50 miles). Logistic and Cox proportional hazards regression models were used for analyses. RESULTS The stage and survival analyses included 146,418 and 178,688 AYAs, respectively. The odds of a late versus early stage at diagnosis (stages III and IV vs I and II) were 1.16 (95% CI, 1.05-1.29) times greater for AYAs living in rural versus metro counties and 1.20 (95% CI, 1.16-1.25) times greater for AYAs living at long versus short distances to the reporting hospital. The hazard of death was 1.17 (95% CI, 1.05-1.31) and 1.30 (95% CI, 1.25-1.36) times greater for those living in rural versus metro counties, respectively, and for long versus short distances to the reporting hospital, respectively. Disease stage mediated 54% and 31% of the associations between metro, urban, or rural residence and residential distance categories and survival. CONCLUSIONS Rural residence and living long distances from the reporting hospital were associated with later stage diagnoses and lower survival in AYAs with cancer. Further research is needed to understand mechanisms. LAY SUMMARY Adolescents and young adults (AYAs) with cancer are a vulnerable population because cancer is of low suspicion in this population and may not be diagnosed in a timely manner. The authors evaluated evidence for geographic disparities in cancer stage at diagnosis and survival in the AYA population. The findings indicate that AYAs living in rural versus metropolitan US counties and those living farther from the diagnosis reporting hospital are more likely to be diagnosed at a later cancer stage, when it is generally less treatable, and have lower survival compared with AYAs living in metropolitan counties.