Development and validation of a nomogram for predicting overall survival of node‐negative ampullary carcinoma

Background The accuracy of the current staging system for predicting the overall survival (OS) of patients with ampullary carcinoma (AC) is still unsatisfactory, especially in node‐negative (N0) patients. We aimed at establishing a nomogram to accurately predict OS in N0 AC. MethodS This study enrolled 697 N0 AC patients from the Surveillance, Epidemiology, and End Results database (design cohort [DC], n = 697) and the First Affiliated Hospital of Sun Yat‐sen University (validation cohort [VC], n = 112), who underwent surgical resection. The nomogram was established by using prognostic factors determined by univariate and multivariate regression analyses. Results The nomogram for OS was developed by using four independent prognostic factors, including age, grade, T stage, and a number of examined lymph nodes. The C‐index of a nomogram for OS in DC and VC was 0.665 and 0.731, respectively. Calibration curves showed good consistency of the nomogram. The nomogram had a better accuracy in predicting OS compared with conventional staging system (P