A Population-Based Retrospective Cohort Study on Colorectal Cancer Survival in Kentucky

Abstract

Colorectal cancer (CRC) mortality in Kentucky exceeds the national average, with recent studies reporting up to a 29.6% increase. Non-Hispanic Blacks (NHBs) and rural residents face higher CRC incidence and worse survival rates. This study investigates factors driving Kentucky’s elevated CRC mortality. This retrospective cohort study analyzed Surveillance, Epidemiology, and End Results (SEER) data from 2000 to 2021, including 42,963 eligible CRC patients from Kentucky. Demographic characteristics, diagnostic outcomes, and treatment modalities were examined. Kaplan-Meier and Cox regression models were used. The highest proportion of distant CRC diagnoses was in NHBs (17.8%), while the lowest was in Non-Hispanic Others (NHOs) (11.9%) (P=0.0001). NHBs also had the highest CRC mortality rate (42.7%) compared to NHOs (22.9%) (P-value < 0.0001). Unadjusted survival time was shortest for NHBs (70.6 months) and longest for NHOs (81.3 months) (P-value < 0.0006). Cox regression analysis (P< 0.0001) showed that counties not adjacent to metropolitan areas had a 13% higher mortality risk than large metro areas. NHBs had an 18% higher CRC mortality risk than Non-Hispanic Whites (NHWs). Patients with regional or distant-stage diagnoses had 165% and 853% higher mortality risks, respectively. Also, those who were not recommended or refused surgery had a 233% higher risk. This study identifies key factors influencing CRC mortality in Kentucky, such as being NHB, rural residency, late-stage diagnosis, and lack of surgical options. These findings highlight the need for targeted public health strategies, access to care, and policy changes to address CRC-related health disparities in Kentucky.