Beyond resection: evaluating survival and surgical quality in colorectal cancer in a Sri Lankan cohort

Introduction: Colorectal cancer (CRC) is a major cause of cancer morbidity and mortality worldwide and its incidence is increasing in many Asian populations, including Sri Lanka. Evaluating surgical outcomes and prognostic determinants is essential for improving colorectal cancer management in this setting.
Methodology: A retrospective cohort study was conducted including all patients who underwent colorectal cancer resection at a tertiary referral centre in Sri Lanka between 2019 and 2023. Clinicopathological variables were extracted from histopathology reports and hospital records. Survival outcomes were determined through hospital documentation and telephone tracing where possible. Kaplan-Meier methods were used to estimate survival, and differences between groups were assessed using the log-rank test. Multivariable Cox proportional hazards regression analysis was performed to identify independent predictors of survival.
Results: A total of 570 patients underwent colorectal cancer resection during the study period. Survival status could be verified in 135 patients (23.7%), while 435 patients (76.3%) remained untraced. Among the traced patients, 47 deaths occurred during follow-up. Estimated overall survival rates were 77.8% (95% CI 70.5-85.1%) at 12 months, 71.1% (95% CI 62.9-79.3%) at 24 months, 65.5% (95% CI 56.4-74.6%) at 36 months, and 59.9% (95% CI 49.8-70.0%) at 60 months. Patients with lymph node yield ≥12 nodes demonstratedsignificantly improved survival compared with those with <12 nodes retrieved (log-rank p<0.001). Tumour stage was also significantly associated with survival, with T4 disease demonstrating poorer outcomes (p<0.001). In multivariable Cox regression analysis, lymph node yield ≥12 (HR 0.22, 95% CI 0.10-0.46) and T4 disease (HR 3.42, 95% CI 1.74-6.71) remained independent predictors of survival.
Conclusion: Adequate lymph node harvest and tumour stage are key determinants of survival following colorectal cancer surgery. However, substantial loss to follow-up limited survival analysis to a subset of patients, highlighting the need for strengthened cancer registries and structured follow-up systems to improve long-term outcome surveillance in Sri Lanka.