Development and Validation of an Individualized Nomogram for Predicting Survival in Patients with Esophageal...

An accurate estimation of prognosis of the esophageal carcinoma patients after surgery is urgently needed. Clinical nomogram has been developed to quantify risk by incorporating prognostic factors for individual patient. Based on the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2013, a total of 4566 patients were selected. Of those, 3198 patients were assigned to training set to construct the nomogram, which incorporated age, gender, histology, grade, T stage, N stage, nodes examined, radiation and chemotherapy. The calibration curve for probability of survival showed good agreement between prediction by nomogram and actual observation. The C-index of the nomogram was 0.71(95%CI 0.70-0.72), which was statistically higher than the TNM staging system. The results were then validated using bootstrap resampling and a validation set of 1368 patients in the SEER database. Besides, in the esophageal squamous cell carcinoma and esophageal adenocarcinoma subgroups, the nomogram discrimination was superior to the TNM staging system. It is likely that these results would play a supplementary role in the current staging system and help to identify the high risk population after surgery.