Development and validation of a nomogram to predict overall survival in young non-metastatic rectal-cancer patients after curative resection: A Population-Based Analysis

Abstract Purpose: This study was aimed to establish and validate a nomogram for predicting overall survival (OS) in young non-metastatic rectal-cancer (RC) patients after curative resection.Methods: Young RC patients (under 50 years of age) from 2010 to 2015 were extracted from the surveillance, epidemiology and results (SEER) database. Those patients randomly assigned to a training cohort and a validation cohort at a ratio of 7:3. The independent prognostic factors for OS were identified by univariate and multivariate Cox regression analysis. A nomogram model was built based on the independent prognostic variables and was evaluated by concordance index (C-index), receiver operating characteristics (ROC) curves, calibration plot and decision curve analysis (DCA).Results: A total number of 3026 young RC patients were extracted from SEER database. OS nomogram was constructed based on race, histological type, tumor grade, T stage, N stage, carcinoembryonic antigen (CEA) level, and number of lymph nodes (LN) examined. C-index, ROC curves, calibration plot and DCA curves presented satisfactory performance of the above nomogram in predicting the prognosis of young non-metastatic RC patients after curative resection. The nomogram can identify three subgroups of patients at different risks, which showed different prognostic outcomes both in the training cohort and validation cohort.Conclusion: We successfully established a reliable and insightful nomogram to predict OS for young non-metastatic RC patients after curative resection. The nomogram may provide accurate prognosis prediction to guide individualized follow-up and treatment plans.