ABSTRACT
BACKGROUND: The benefits of chemotherapy in stage II colon cancer remain unclear, but it is recommended for high-risk stage II disease. Which patients receive chemotherapy and its impact on survival remains undetermined. METHODS: The National Cancer Database was surveyed between 2004 and 2016 for stage II colon cancer patients. Patients were categorized as high- or average-risk as defined by the National Comprehensive Cancer Network. The demographic characteristics of high- and average-risk patients who did and did not receive chemotherapy were compared using univariate and multivariable analyses. The survival of high- and average-risk patients was compared based on receipt of chemotherapy with Cox hazard ratios and Kaplan-Meier curves. RESULTS: Overall, 84,424 patients met the inclusion criteria. A total of 34,868 patients were high-risk and 49,556 were average-risk. In high-risk patients, the risk factors for not receiving chemotherapy included increasing age, distance from the treatment facility, Charlson-Deyo score, and lack of insurance. In average-risk patients, factors associated with receipt of chemotherapy were decreasing age, distance from the treatment facility, Charlson-Deyo score, and non-academic association of the treatment facility. In both, chemotherapy was significantly associated with increased survival on the Kaplan-Meier curve. In the Cox hazard ratio, only high-risk patients benefited from chemotherapy (hazard ratio 1.183, confidence interval 1.116-1.254). CONCLUSIONS: Factors associated with not receiving chemotherapy in high-risk stage II colon cancers included increasing age, medical comorbidities, increasing distance from the treatment facility, and lack of insurance. Chemotherapy is associated with improved overall survival in high-risk patients.
