Long-term Outcomes of Surgery for Colorectal Cancer: A 20-Year Study

Background: Colorectal cancer is a common and potentially deadly diagnosis. Surgery is the treatment of choice. Data of outcomes beyond 10 y are sparse. This study attempts to identify factors influencing long-term survival. Methods: This cohort study examines a prospectively collected database of patients undergoing colorectal resections from January 1996 to May 2006. Variables were analyzed by plotting Kaplan-Meier survival curves and Cox regression analysis to identify independent predictors of survival. Results: Six hundred fifty-seven patients were included in this analysis. Three hundred sixty underwent resection for rectal cancer. Median follow-up time was 11.7 y (interquartile range 2.8-15.4). Metachronous cancers occurred following 5.4% (confidence intervals [CI] 3.4-8.4) of resections for colorectal malignancy at 15 y. Mean age at death was higher in patients with higher Australian clinicopathological score (A: 82.4, B: 78.9, C: 75.5, D: 68.9). Multivariable analysis revealed age at diagnosis (hazard ratio [HR] 1.02, CI 1.011.03), Australian clinicopathological score (B: HR 1.47, CI 1.08-2.01; C: 2.11, CI 1.51-2.93; D: HR 11.12, CI 8.12-15.13), American Society of Anesthesiology score (ASA2: HR 1.66, CI 1.032.67; ASA3: HR 2.00, CI 1.20-3.34; ASA4: HR 3.39, CI 1.95-6.25), and operating for locoregional recurrence (HR 1.82, CI 1.21-2.76) to be associated with increased mortality. Adjuvant chemotherapy was associated with improved survival (HR 0.64, CI 0.49-0.84). Conclusions: Age at diagnosis, American Society of Anesthesiology score, and stage of disease were the principal predictors of long-term survival. Adjuvant chemotherapy was found to improve survival. Metachronous cancers occurred in a minority of patients. (C) 2018 Elsevier Inc. All rights reserved.