Safety and Survival Benefit of Adjuvant Chemotherapy for Elderly Patients With Stage II/III Colon Cancer

Background/Aim: To evaluate the safety and survival benefits of adjuvant chemotherapy (AC) in elderly patients who underwent radical resection for stage II/III colon cancer. Patients and Methods: This retrospective study included patients aged >70 years treated at a tertiary hospital between January 2012 and December 2017. We evaluated the clinical and pathological characteristics and adverse events of chemotherapy. The 5-year overall survival (OS) and diseasefree survival (DFS) of the surgery-only (SO) and AC groups were compared by stage using the Kaplan-Meier method and Cox-regression analysis. Results: Of the 163 patients included in the study, 75 were diagnosed with stage II cancer, with 43 patients in the SO group and 32 in the AC group. A total of 88 patients were diagnosed with stage III cancer, including 20 in the SO group and 68 in the AC group. Patients with stage II disease in the SO group were older, with less frequent venous invasion than the AC group. Comorbidities, tumor location, and surgical methods did not differ. In stage III, age, comorbidities, tumor location, surgical methods, and pathological outcomes did not differ. The 5-year OS and DFS did not differ significantly in those with stage II disease but were significantly better in the AC than the SO group in stage III cases (48.2% vs. 71.6%, p=0.012; and 42.6% vs. 60.0%, p=0.029). Conclusion: AC may provide a survival advantage in elderly patients with stage III colon cancer.