Rural-urban disparities in colorectal cancer-related mortality changes in the United States.

Abstract

e13714 Background: Colorectal cancer is the second leading cause of cancer-related death in the world. The incidence of colorectal cancer rates is higher in rural areas compared to urban populations which is attributed to obesity, and lower adherence to screening. It is hence vital to identify large population-based data on rural and urban disparities in colorectal cancer-related mortality. We, therefore, sought to analyze the outcome variances between urban and rural populations. Methods: We retrieved the mortality data from the Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research (CDC WONDER) multiple causes of death database (years:1999-2020) for patients aged 15 years and above, with malignant neoplasm of colorectum (ICD-10: C18.9, C19, C20) listed as underlying cause of death. We analyzed age-adjusted mortality rates (AAMRs) per 100,000 population and assessed temporal trends in the average percent change (APC) of AAMRs by applying the simplest model with a maximum of 3 joinpoints (using the Joinpoint regression program 5.0.2). We conducted nonparallel pairwise comparisons to assess differences in trends between large metropolitan, small/medium metropolitan, and rural areas (per National Center for Health Statistics Urban- Rural Classification Scheme, 2016) using average annual percentage change difference (AAPCD). Results: A total of 810,577 colorectal cancer-related deaths were retrieved, amongst which 418,744 (51.6%), were in the large metropolitan, 249,933 (30.8%) were in the small/medium metropolitan, and 141,900 (17.5%) were in the rural regions. We noted a decline in the AAMR overall and across large metropolitan, small/medium metropolitan, and rural areas. However, the decline in AAMR was significantly higher among large metropolitan areas as compared to rural areas (AAPCD: -1.0043, 95% CI -1.64, -0.35, p=0.0022). There was no statistically significant difference in decline in AAMR when large metropolitan areas were compared to small/medium metropolitan (AAPCD: -0.4517, 95% CI -0.90, -0.002, p=0.051) and when small/medium metropolitan were compared to rural areas (AAPCD: -0.5526, 95% CI -1.16, -0.05, p=0.07). Conclusions: We identified discrepancies in the decline in colorectal cancer AAMR between urban and rural areas. A substantially lower decline in AAMR is eminent in the rural regions, as compared to the large metropolitan counterparts. This raises the concern for poor access to cancer care in this population group. Our results emphasize the imperative of prioritizing and designing strategies to ensure healthcare equity in rural areas. [Table: see text]