V. Madabhushi1, B. J. Shelton3, A. Shearer3, R. Cardarelli2 1University Of Kentucky,Department Of General Surgery,Lexington, KY, USA 2University Of Kentucky,Department Of Family And Community Medicine,Lexington, KY, USA 3University Of Kentucky,Biostatistics And Bioinformatics Shared Resource Facility, Markey Cancer Center,Lexington, KY, USA
Introduction: Colon cancer mortality is significantly higher in Kentuckians, compared to the national average. The Appalachian region of Kentucky, which is a region of the state with significant health disparities, has an even higher mortality from colon cancer. However, colon cancer is curable with surgical resection, if diagnosed in the early stages and resected in a timely manner. The first treatment modality for colon cancer in stages I, II, and III is surgical resection. The study compares the time to surgery and survival for patients with stages I-III colon cancer amongst Appalachian and non-Appalachian Kentuckians.
Methods: This IRB-approved, retrospective study reviewed the Kentucky Cancer Registry for all patients diagnosed with stages I-III colon cancer in the state between July 1st, 2008 and June 30th, 2018. Demographic data, comorbidities, and treatment information was obtained for each of these patients. Demographic data was analyzed using descriptive statistics. Survival analysis was performed using Kaplan-Meier estimation, and comparisons of survival distributions were made using log-rank statistic. Multivariable modeling included Cox Proportional Hazards regression for time-to-event (survival) outcome, and analysis of time-to-surgery was performed using linear regression modeling.
Results: 9357 surgical patients were identified, with 2800 from Appalachian Kentucky and 6,557 from non-Appalachian Kentucky. The mean age of diagnosis amongst the Appalachian patients was 66.5 years, compared to 67.8 years in the non-Appalachian group (p<0.001). There was no significant difference in the gender or stage distribution amongst the two groups. Amongst patients with stage II and III colon cancer, there was not a significant difference in time to resection between Appalachian and non-Appalachian patients. However, there was nearly a 6 day delay in resection in Appalachian patients with stage I (P<0.001). Additionally, Appalachian patients with more than 3 comorbidities waited nearly 8 days longer for resection, regardless of stage. Bivariate analyses revealed a slightly favorable, albeit significant, survival advantage for non-Appalachian patients (Hazard Ratio=1.09, p=0.0186). Furthermore, upon adjustment for stage, age at diagnosis, gender, and comorbidities, Appalachian Kentuckians have significantly poorer survival (Hazard Ratio – 1.21, p <0.001), compared to compared to non-Appalachians.
Conclusion: This study showed that Appalachian patients with stages I-III colon cancer had more days to resection compared to non-Appalachians. Furthermore, Appalachian patients fared worse than their non-Appalachian counterparts in terms of survival from resectable colon cancer. Given these findings, further studies are needed to assess the etiology and develop interventions to improve survival in this vulnerable population.