Enduring Cancer Disparities by Persistent Poverty, Rurality, and Race: 1990-1992 to 2014-2018

Background: Most persistent poverty counties are rural and contain high concentrations of racial minorities. Cancer mortality across persistent poverty, rurality, and race is understudied. Methods: We gathered data on race and cancer deaths (all sites, lung and bronchus, colorectal, liver and intrahepatic bile duct, oropharyngeal, breast and cervical [females], and prostate [males]) from the National Death Index (1990-1992; 2014-2018). We linked these data to county characteristics: 1) persistent poverty or not; and 2) rural or urban. We calculated absolute (range difference [RD]) and relative (range ratio [RR]) disparities for each cancer mortality outcome across persistent poverty, rurality, race, and time. Results: The 1990-1992 RD for all sites combined indicated persistent poverty counties had 12.73 (95% confidence interval [CI] = 11.37 to 14.09) excess deaths per 100000 people per year compared with nonpersistent poverty counties; the 2014-2018 RD was 10.99 (95% CI = 10.22 to 11.77). Similarly, the 1990-1992 RR for all sites indicated mortality rates in persistent poverty counties were 1.06 (95% CI = 1.05 to 1.07) times as high as nonpersistent poverty counties; the 2014-2018 RR was 1.07 (95% CI = 1.07 to 1.08). Between 1990-1992 and 2014-2018, absolute and relative disparities by persistent poverty widened for colorectal and breast cancers; however, for remaining outcomes, trends in disparities were stable or mixed. The highest mortality rates were observed among African American or Black residents of rural, persistent poverty counties for all sites, colorectal, oropharyngeal, breast, cervical, and prostate cancers. Conclusions: Mortality disparities by persistent poverty endured over time for most cancer outcomes, particularly for racial minorities in rural, persistent poverty counties. Multisector interventions are needed to improve cancer outcomes.