Poverty and Mortality Risk in Patients With Colorectal Cancer.

IMPORTANCE

Colorectal cancer (CRC) is the third most common cancer in the US, accounting for 9% of all cancer deaths. People in persistent poverty areas-where at least 20% have lived in poverty for at least 30 years-face higher colorectal cancer mortality than those in other areas.

OBJECTIVE

To investigate which risk factors mediated the association between living in persistent poverty areas and mortality, specifically disease severity and aggressiveness, type of CRC treatment, quality of treatment, access to medical care, and complications.

DESIGN, SETTING, AND

PARTICIPANTS

This retrospective cohort study used linked data from the Central Cancer Registry, Death Certificates, and the All-Payer Claims Database (APCD) from January 2013 to June 2023. The population included patients from urban census tracts in Arkansas who were newly diagnosed with colorectal cancer. Analyses were conducted between May and September 2025.

EXPOSURE: Residence in a persistent poverty census tract.

MAIN OUTCOME AND MEASURES: The main outcome was overall survival. Potential confounders (including demographics and comorbidities) and potential mediators (including disease severity and aggressiveness, type and quality of treatment, health care access, and complications) were also examined.

RESULTS

Among 5028 patients newly diagnosed with CRC in 382 urban census tracts, 2587 (51.5%) were male; 705 (14.0%) were Black, 4142 (82.4%) were White, and 181 (3.6%) were of other race or ethnicity; and 2371 (47.2%) were married, with a mean (SD) age of 64.6 (13.7) years. Among 617 patients living in persistent poverty tracts, 329 (53.3%) died, vs 1927 of 4411 (43.7%) in other tracts (hazard ratio, 1.17; 95% CI, 1.03-1.33). There was significant evidence of mediation by stage at diagnosis (33.7% mediation; 95% CI, 7.4%-89.5%; P = .01), not having surgery (29.3% mediation; 95% CI, 5.5%-87.2%; P = .02), and type of health insurance (13.8% mediation); 95% CI, 2.2%-55.3%; P = .03).

CONCLUSION AND RELEVANCE: In this retrospective cohort study of patients with CRC in urban persistent poverty areas, more advanced stage, not receiving surgery, and type of health insurance were key mediators of their increased risk of mortality. Improved awareness of these mediators may help inform targeted interventions to reduce the risk of mortality in this population.