Impact of severe postoperative complications on the prognosis of older patients with colorectal cancer: a two-center retrospective study

Background The occurrence of postoperative complications may affect short-term outcomes and prognosis of patients with various malignancies. However, the prognostic impact of these complications in older patients with colorectal cancer (CRC) remains unclear. Therefore, this study aimed to investigate the impact of severe postoperative complications on the oncological outcomes of older (aged >= 80 years) and non-older (aged < 80 years) patients with CRC. Methods We retrospectively analyzed 760 patients with stage I-III CRC who underwent curative surgery in two institutions between 2013 and 2019. The patients were categorized into older (aged >= 80 years, 191 patients) and non-older (aged < 80 years, 569 patients) groups. Short- and long-term outcomes were compared between the two groups. Results The incidence of severe postoperative complications did not differ between the two groups (p = 0.981). Cancer-specific survival (CSS) was significantly worse in older patients with severe complications than in those without severe complications (p = 0.007); meanwhile, CSS did not differ between the non-older patients with severe complications and those without severe complications. Survival analysis revealed that the occurrence of severe postoperative complications was an independent prognostic factor for CSS in older patients (hazard ratio = 4.00, 95% confidence interval: 1.27-12.6, p = 0.017). Conclusion CRC surgery can be safely performed in older and non-older patients. Moreover, the occurrence of severe postoperative complications might more strongly affect the prognosis of older patients than that of non-older patients.