The Intersection of Race and Rurality and its Effect on Colorectal Cancer Survival

Outcomes in colorectal cancer treatment are historically worse in Black people and residents of rural areas. Purported reasons include factors such as systemic racism, poverty, lack of access to care, and social determinants of health. We sought to determine whether outcomes worsened when race and rural residence intersected.

The National Cancer Database was queried for individuals with stage II-III colorectal cancer (2004-2018). To examine the intersectionality of race/rurality on outcomes, race (Black/White) and rurality (based on county) were combined into a single variable. Main outcome of interest was 5-year survival. Cox hazard regression analysis was performed to determine variables independently associating with survival. Control variables included age at diagnosis, sex, race, Charlson-Deyo score, insurance status, stage, and facility type.

Of 463 948 patients, 5717 were Black-Rural, 50 742 were Black-Urban, 72 241 were White-Rural, and 33 5271 were White-Urban. Five-year mortality rate was 31.6%. Univariate Kaplan-Meier survival analysis demonstrated race-rurality was associated with overall survival (P < .001), with White-Urban having the greatest mean survival length (47.9 months) and Black-Rural with the lowest (46.7 months). Multivariable analysis found that Black-Rural (1.26, 95% confidence interval [1.20-1.32]), Black-Urban (1.16, [1.16-1.18]), and White-Rural (HR: 1.05; (1.04-1.07) had increased mortality when compared to White-Urban individuals (P < .001).

Although White-Rural individuals fared worse than White-Urban, Black individuals fared worst of all, with the poorest outcomes observed in Black individuals in rural areas. This suggests that both Black race and rurality negatively affect survival, and act synergistically to further worsen outcomes.