Gold standard management of stage III colon cancer includes surgical resection and adjuvant chemotherapy. Despite improved overall survival with adjuvant chemotherapy in stage III colon cancer, it is reportedly underused in older adults. To date, no contemporary national analysis of adjuvant chemotherapy use and its impact in older adults with stage III colon cancer exists.

To assess current use of adjuvant chemotherapy in older adults with stage III colon cancer and determine factors associated with noncompliance.

Retrospective cohort study.

Conducted using the National Cancer Database.

Patients 65 years and older undergoing curative resection for stage III colon adenocarcinomas from 2010-2017.

Adjuvant chemotherapy use, factors associated with adjuvant chemotherapy use, and overall survival with and without adjuvant chemotherapy in older adults with pathologic stage III disease.

Of 64,608 patients included, 64.3% received adjuvant chemotherapy. Adjuvant chemotherapy was significantly independently associated with improved 1-, 3-and 5-year overall survival versus no adjuvant chemotherapy (92.8%, 75.3%, 62.4% vs. 70.8%, 46.6%, 32.7%; respectively, HR 0.475, 95% CI 0.459-0.492, p < 0.001). Compared with the no adjuvant chemotherapy cohort, patients who received adjuvant chemotherapy were younger, female, and less co-morbid (p < 0.001). Factors associated with adjuvant chemotherapy noncompliance included advancing age (OR 0.857, 95% CI 0.854-0.861), lower annual income (OR 0.891, 95% CI 0.844-0.940), open approach (0.730, 95% CI 0.633-0.842), longer length of stay (OR 0.949, 95% CI 0.949-0.954), pathologic stage IIIA (0.547, 95% CI 0.458-0.652), and <12.

Administrative data source with inherent risks of bias, coding errors, and limitations in the fields available for analysis.

Adjuvant chemotherapy significantly improved overall survival but was only used in 64.3% of older adults with stage III colon cancer. Adjuvant chemotherapy noncompliance was seen in the most vulnerable and highest risk patients, including those with greater co-morbidity, lower income, and patients who received open surgery. See Video Abstract at http://links.lww.com/DCR/C125.