Prognostic nomograms for patients undergoing radical operation for stage I-III appendiceal adenocarcinoma

Objective: To develop nomograms for effective prediction of cause-specific survival (CSS) and overall survival (OS) of patients who underwent radical operation for stage I-III appendiceal adenocarcinoma. Methods: Clinical information from the surveillance, epidemiology, and end results database was retrieved from 2004 to 2015 and subjected to multivariate analysis to explore variables that affect the OS and CSS. Results were used to construct nomograms to assess the 1-, 3-, and 5-year OS and CSS rates, then their calibration accuracy and discriminative power were examined using Kaplan-Meier curves, calibration plots, and C statistics. Results: Overall, 1,241 patients were included in the analysis. We found 7 and 5 factors that could independently alter the prognosis, then used for creating nomograms for evaluating the OS and CSS, respectively, with respective C-index values of 0.741 (95% confidence interval [CI]: 0.729-0.754) and 0.747 (95% CI: 0.733-0.762). Calibration and receiver operating characteristic curves further revealed excellent predictive performance. Conclusions: We successfully built highly accurate nomograms for evaluating the 1-, 3-, and 5-year CSS and OS rates in subjects who underwent radical operation for stage I-III appendiceal adenocarcinoma. Further studies, involving prospective validations, are required to validate these nomograms.