Racial and regional disparities in the management of locally advanced rectal cancer.

Abstract

14 Background: Surgical margins following rectal cancer resection impact oncologic outcomes and may reflect adequacy of care. We examined the relationship between race, ethnicity, or region of care with margin positivity following rectal cancer resection. Methods: We queried the National Cancer Database (NCDB) for patients diagnosed with stage II-IV rectal cancer between 2004-2018 who underwent surgical resection and excluded patients with missing data for race/ethnicity and radiation therapy/surgery status, and/or who had local excision only. We performed a propensity-score analysis via inverse probability of treatment weighting (IPTW) of margin positivity rate as outcome and race/ethnicity and region as predictors of interest. We controlled for age, sex, Charlson-Deyo Score, pathologic stage, pathologic grade, time from diagnosis to surgical resection, surgery type, sequence of radiation and surgery, facility type, insurance type, level of education, distance between patient and facility, and region of the United States. Results: Our query yielded 73,269 patients. Median patient age was 63 (IQR: 54-72) years and 40% were female. 81%,8%, 6%, and 5% were non-Hispanic White, non-Hispanic Black, Hispanic, and non-Hispanic Other, respectively. After IPTW adjustment, non-Hispanic Black patients had 19% higher odds of margin positivity relative to non-Hispanic White patients (OR: 1.185, 95% CI: 1.094-1.284; p<.0001) Patients in the Northeast United States had a 10% lower odds of margin positivity compared to those in the South (OR: 0.900, 95% CI: 0.842-0.962; p=0.0019). Conclusions: Being non-Hispanic Black was significantly associated with a higher likelihood of positive margin following rectal cancer resection when compared to their non-Hispanic White counterparts. Patients in the South also experienced significantly higher rates of positive margin when compared to Northeast patients. Further investigation into potential interactions between racial and regional disparities and other contributors is warranted.[Table: see text]