Predictors of Early In-Hospital Mortality in Patients Aged ≥ 65 Years Undergoing Colorectal Cancer Surgery: A Retrospective Cohort Study

Background/Objectives: Patients aged ≥ 65 years undergoing colorectal cancer surgery are at increased risk of postoperative complications and mortality due to advanced age, comorbidity burden, frailty, and reduced physiological reserve. The aim of this study was to evaluate perioperative predictors associated with early in-hospital mortality in patients aged ≥ 65 years undergoing colorectal cancer surgery. Methods: This single-center retrospective cohort study included 438 patients aged ≥ 65 years who underwent colorectal cancer surgery at a tertiary referral center between January 2017 and December 2018. Demographic characteristics, comorbidities, American Society of Anesthesiologists (ASA) classification, surgical urgency, perioperative laboratory parameters, and transfusion requirements were analyzed. The primary endpoint was early in-hospital mortality. Survival analysis was performed using Kaplan–Meier curves and Cox proportional hazards regression analysis. Results: The overall in-hospital mortality rate was 9.4% (41/438). Emergency surgery was associated with significantly reduced in-hospital survival compared with elective procedures (log-rank p < 0.001). Non-survivors more frequently presented with emergency surgical indications, higher ASA scores, greater comorbidity burden, anemia, nutritional impairment, elevated inflammatory markers, renal dysfunction, and increased transfusion requirements. In univariate Cox regression analysis, emergency surgery, ASA score ≥ 3, elevated creatinine, leukocyte count, and C-reactive protein levels, lower hemoglobin, albumin and total protein levels, and red blood cell transfusion were significantly associated with mortality. In multivariate analysis, elevated creatinine (HR 1.004, p = 0.030), leukocyte count (HR 1.064, p = 0.004), C-reactive protein (HR 1.009, p < 0.001), and lower hemoglobin concentration (HR 0.938, p < 0.001) remained independent predictors of in-hospital mortality. Conclusions: Early in-hospital mortality after colorectal cancer surgery in patients aged ≥ 65 years is associated with systemic inflammation, anemia, and renal dysfunction. Routinely available clinical and laboratory parameters may assist in identifying high-risk patients and improving perioperative risk assessment and postoperative management.