Predicting disease-free survival following curative-intent resection of right-sided colon cancer using a pre- and post-operative nomogram: a prospective observational cohort study

INTRODUCTION: Disease prognostication can be achieved through the derivation of biologically and clinically integrated prediction models. The present study reports 1-, 3-, and 5-year disease-free survival (DFS) in patients undergoing right hemicolectomy for curative intent and both derives and validates a pre- and post-operative prediction tool for DFS for prognostication and risk stratification purposes. METHOD: Consecutive patients undergoing right-sided curative-intent resection for colorectal cancer (2010-2020) in a tertiary care unit were followed-up prospectively for recurrence and survival outcomes. Survival analyses were used to derive pre- and post-operative models predicting 1-, 3-, and 5-year DFS. Calibration was reported and internal validation was performed using bootstrapping. RESULTS: A total of 822 patients underwent resection and 528 had ≥5-year follow-up. The 1-, 3-, and 5-year DFS rates were 85.6%, 72.5% and 57.6%, respectively. Variables associated with death/recurrence included: increasing age (HR > 1.95, P = 0.037), male gender (HR 1.62, P < 0.001), ASA ≥3 (HR 1.79, P < 0.001), low albumin (HR 1.54, P < 0.001), T4 stage (HR 2.35, P = 0.023), R1 status (HR 1.63, P = 0.024), ≥4 positive lymph nodes (HR > 1.74, P < 0.001) and Clavien-Dindo ≥3 (HR 2.83, P < 0.001). The pre- and post-operative models contained 9 and 13 demographic, clinical, biochemical, operative and pathological variables, respectively (C-index 0.75 and 0.79, respectively). Excluding demographic, clinical and operative variables significantly reduced the C-index of the pre- (0.62) and post-operative models (0.70). CONCLUSION: The presented prediction tools for DFS will help clinicians stratify risk, offer appropriate adjuvant treatment and predict long-term DFS following curative-intent right-sided colon cancer resection.