Age-related differences in adjuvant chemotherapy use and outcomes in stage II colon cancer: a retrospective cohort study

While the benefit of adjuvant chemotherapy in stage II colon cancer remains uncertain, less is known about how age influences its use and associated outcomes in this population. Retrospective cohort study. Patients who underwent radical colon cancer surgery, from 2013 to 2018, divided into age groups; 18–49 (young), 50–64 (middle aged), and 65–75 (older) years. To compare the adjuvant therapy and survival of patients with stage II colon cancer in different age groups. At baseline, the young showed fewer comorbidities (16.1% vs. 37.2% vs. 54.9%, p < 0.001) than the middle-aged and older groups, and the pathological results showed worse differentiation types (25.8% vs. 7.4% vs. 6.1%, p = 0.017), but more microsatellite instability-high status (21.51% vs. 9.10% vs.10.57%, p = 0.005). Among patients with stage II colon cancer, young and middle-aged patients were more likely to receive adjuvant chemotherapy [odds ratio (OR): 4.196 (95% confidence interval (CI), 2.247–7.835); 2.610 (95% CI, 1.743–3.910)]. Among patients receiving adjuvant chemotherapy, young and middle-aged patients were more likely to receive multi-drug chemotherapy than older patients [OR: 3.181 (95% CI, 1.255–8.064); 2.642 (95% CI, 1.386–5.036)]. There was no significant difference in survival among patients with stage II colon cancer who underwent surgery alone or surgery combined with adjuvant chemotherapy among different age groups. Among patients with stage II colon cancer, young and middle-aged patients were more likely to receive adjuvant chemotherapy and more aggressive chemotherapy regimens, but this was not associated with survival benefits compared to the older age group.