The association of postoperative morbidity and age on 5‐year survival after colorectal surgery in the elderly population: a nationwide cohort study

Abstract

AbstractAimThis study aimed to evaluate the association of age and postoperative morbidity on 5‐year overall survival (OS) after elective surgery for colorectal cancer.MethodPatients undergoing elective, curatively intended surgery for colorectal cancer Union for International Cancer Control Stages I–III between January 2014 and December 2019 were selected from four Danish nationwide healthcare databases. Patients were divided into four groups: group I 65–69 years old; group II 70–74 years old; group III 75–79 years old; and group IV ≥80 years old. Propensity score matching was used to reduce potential confounding bias. The primary outcome was the association of age and postoperative morbidity with 5‐year OS. The secondary outcome was conditional survival, given that the patient had already survived the first 90 days after surgery.ResultsAfter propensity score matching with a 1:1 ratio, group II contained 2221 patients; group III 952 patients; and group IV 320 patients. There was no significant difference in 5‐year OS between group I (reference) and groups II and III (P = 0.4 and P = 0.9, respectively). Patients with severe postoperative complications within 30 days after surgery had a significantly decreased OS (P < 0.01); however, when patients who died within the first 90 days were excluded from the analysis, the differences in 5‐year OS were less pronounced across all age groups.ConclusionPostoperative morbidity, and not patient age, was associated with a lower 5‐year OS. Long‐term survival for patients who experience a complication is similar to patients who did not have a complication when conditioning on 90 days of survival.