Abstract 7117: Short-term surgical outcomes for colon adenocarcinoma: Racial-ethnic comparisons in the Military Health System

Abstract Background: Racial-ethnic disparities in receipt of treatment and survival outcomes of colon cancer have been documented in the general U.S. population, with access to care identified as a contributor to the disparities. Less is known about disparities in quality aspects of colon cancer surgery, such as achievement of negative surgical margins, adequate lymphadenectomy, and complication rates. We aimed to study colon cancer surgery and postoperative outcomes in the Military Health System (MHS), which provides access to care regardless of patient demographic or socioeconomic characteristics, to better understand racial-ethnic disparities in surgical oncology care in an equal access setting. Material and Methods: We used the MilCanEpi database to identify patients aged 18 or older who were diagnosed with stage I-III colon adenocarcinoma between 2001 and 2014 and received colectomy as primary surgical treatment. The occurrence of positive surgical margins, inadequate lymphadenectomy (&lt12 nodes examined), 30-day complications (general: surgical site infection, hemorrhage, myocardial infarction, stroke, thrombosis; or gastrointestinal: bowel obstruction or intra-abdominal abscess), and 30-day inpatient admissions were captured. Multivariable logistic regression models estimated the adjusted odds ratios (AORs) and 95% confidence intervals (CIs) in association with race-ethnicity for each outcome. Results: The study included 157 Asian, 257 non-Hispanic Black, 110 Hispanic, and 1115 non-Hispanic White patients. Overall, the frequency of positive margins (7.6%), inadequate lymphadenectomy (28.9%), 30-day complications (33.1%), or 30-day inpatient admissions (14.3%) did not differ significantly between racial-ethnic groups (all AORs and their 95% CIs included 1.00). By complication type (general or gastrointestinal), Hispanic patients had a significantly lower likelihood of bowel obstruction (AOR=0.48, 95% CI=0.25, 0.95) compared to non-Hispanic White patients, with no other statistically significant racial-ethnic differences. Conclusions: In the equal access MHS, there were no overall significant racial-ethnic differences in margins, lymphadenectomy, or 30-day outcomes of colectomy for non-metastatic colon cancer. Our findings highlight the role of access to care in minimizing racial or ethnic disparities in colon cancer surgery and postoperative outcomes in the U.S. Citation Format: Yvonne L. Eaglehouse, Sarah Darmon, Michele M. Gage, Craig D. Shriver, Kangmin Zhu. Short-term surgical outcomes for colon adenocarcinoma: Racial-ethnic comparisons in the Military Health System [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 7117.