Geographic and Demographic Disparities in Colorectal Cancer: A National Cancer Database Analysis.

Background and objectives: Area of residence may adversely affect survival and outcomes in many cancers. The objective of this study was to evaluate the impact of geographical and demographic disparities on survival of patients with colorectal cancer.

Materials and methods: Data were obtained from the National Cancer Database (NCDB) colon, rectosigmoid, and rectal datasets. Patients were categorized by area of residence, namely, metropolitan (MA), urban (UA), or rural (RA). Sociodemographic and tumor-related data were collected and analyzed to evaluate variables affecting overall survival (OS).

Results: In total, 973,139 patients between 2004 and 2013 were included in the study, of which 83%, 15%, and 2% were MA, UA, and RA residents, respectively. RA and UA patients were mostly white male with low income and no comorbidities. In univariate analysis, OS was worse for RA (hazard ratio [HR] 1.10) and UA (HR 1.06) colorectal cancer patients than that for MA colorectal cancer patients. In multivariate analysis revealed significant association between OS and geographic residence, with worse OS for RA (HR 1.02, p = 0.04) and UA (HR 1.01, p = 0.003) patients. Black (HR 1.14) and Native American (HR 1.17) patients had worse outcomes, while Asians (HR 0.8), women (HR 0.88), and patients with higher income had improved OS (HR 0.88).

Conclusion: The differences in the OS for RA and UA patients with colorectal cancer were significantly driven by economic disparity. Area of residence represents an important factor independently limiting access to care, particularly in geographically isolated individuals.