Rectal Cancer Disparities Among the American Indian/Alaskan Native Populations.

Area of Science:

• Oncology
• Health Disparities
• Epidemiology

Background:

• Previous research indicated lower overall survival (OS) for American Indian/Alaskan Native (AI/AN) individuals with colon cancer compared to non-Hispanic White (NHW) populations.
• Demographic and survival data for rectal cancer in AI/AN populations remain underreported.

Purpose of the Study:

• To investigate disparities in rectal cancer diagnosis and outcomes between AI/AN and White patient groups.
• To identify differences in demographic profiles and survival rates for rectal cancer between these populations.

Main Methods:

• Utilized the National Cancer Database (NCDB) to identify White and AI/AN patients diagnosed with rectal adenocarcinoma between 2004 and 2020.
• Performed unadjusted and adjusted analyses to compare demographic and clinical characteristics, including standardized differences (stddiff).
• Conducted survival analyses for Stage II/III rectal cancer using Kaplan-Meier methods and multivariate Cox-proportional hazards modeling.

Main Results:

• Identified 176,341 eligible cases (0.6% AI/AN, 99.4% White).
• AI/AN patients were diagnosed at a younger mean age (59.9 vs. 64.5 years) and presented with more advanced stage disease (44.8% vs. 43.7%).
• AI/AN patients disproportionately resided in lower-income areas (35.5% vs. 15.1%), rural locations (9.9% vs. 2.2%), and primarily used Medicaid (14.3% vs. 6.2%).
• Adjusted analyses revealed an increased hazard of death for AI/AN patients (HR, 1.14; 95% CI, 1.05-1.25; p=0.003).

Conclusions:

• AI/AN individuals with rectal cancer are diagnosed at a younger age and with more advanced disease.
• AI/AN race is independently associated with lower overall survival compared to White patients.
• Future interventions should prioritize enhanced colorectal cancer screening and improved treatment access for AI/AN populations to improve survival outcomes.