Mediating Factors Between Race and Time to Treatment in Colorectal Cancer

Dis Colon Rectum. 2021 Dec 20. doi: 10.1097/DCR.0000000000002214. Online ahead of print.


BACKGROUND: Previous disparities research has demonstrated that underrepresented racial minority patients have worse colorectal cancer outcomes and that they experience unnecessary delays in time to treatment. These delays may explain worse colorectal cancer outcomes for minority patients and serve as a marker of inequalities in our healthcare system.

OBJECTIVE: This study aims to quantify the mechanisms that contribute to this disparity in treatment delay.

DESIGN: This is a retrospective analysis of colorectal cancer patients who underwent elective resection from 2004-2017. A causal inference mediation analysis using the counterfactual framework was utilized to estimate the extent to which racial disparities amongst patient factors explain the racial disparities in time to treatment. Mediators included income, education, comorbidities, insurance, and hospital type.

SETTINGS: This study was conducted at hospitals participating in the National Cancer Database.

PATIENTS: Stage I-III colorectal cancer patients, ≥18 years old, who underwent elective resection from 2004-2017 were included.

MAIN OUTCOMES MEASURES: The primary measures were indirect effect of mediators between race and delayed time to treatment.

RESULTS: Of the 504,405 patients (370,051 colon, 134,354 rectal), 10%, 5%, 4% were Black, Hispanic and Other, respectively. In multivariable models, compared to White patients, these patients had 25%, 27% and 17% greater odds of delayed treatment. Mediation analyses suggested that 43%, 20%, 31% of the treatment delay among, respectively, could be removed if an intervention equalized income, education, comorbidities, insurance, and hospital type to that of White patients. Treatment at an academic hospital explained 15%-32% of the racial disparity and was the most potent mediator.

LIMITATIONS: This study was limited by its retrospective design; failure to capture all meaningful mediators.

CONCLUSIONS: Black, Hispanic, and Other colorectal cancer patients experience treatment delays when compared to White patients. Equalization of the mediators used in this study could reduce treatment delays by 20-43% depending on racial/ethnic group. Future research should identify other causes of racial disparities in treatment delay and intervene upon them. See Video Abstract at

PMID:34933318 | DOI:10.1097/DCR.0000000000002214