Predictive value of nomogram based on Kyoto classification of gastritis to diagnosis of gastric cancer

Background and Aim It is important to predict the risk of gastric cancer (GC) for endoscopists because early detection of GC determines the selection of the best treatment strategy and the prognosis of patients. The study aimed to evaluate the utility of a predictive nomogram based on the Kyoto classification of gastritis for GC. Methods It was a retrospective study that included 2639 patients who received esophagogastroduodenoscopy and serum pepsinogen (PG) assay from January 2019 to November 2019 at the Endoscopy Center of the Department of Gastroenterology, Wenzhou Central Hospital. Routine biopsy was conducted to determine the benign and malignant lesions pathologically. All cases were randomly divided into the training set (70%) and the validation set (30%) by using the bootstrap method. A nomogram was formulated according to multivariate analysis of the training set. The predictive accuracy and discriminative ability of the nomogram were assessed by concordance index (C-index), area under the curve (AUC) of receiver operating characteristic curve (ROC) as well as calibration curve and were validated by the validation set. Results Among all patients enrolled, 102 of 2636 cases showed LGIN, HGIN and gastric cancer pathology results, whereas the rest cases showed benign pathological results. Multivariate analysis indicated that age, sex, PG I/II ratio and Kyoto classification scores were independent predictive variables for GC. The C-index of the nomogram of the training set was 0.79 (95% CI: 0.74 to 0.84) and the AUC of ROC is 0.79. The calibration curve of the nomogram demonstrated an optimal agreement between predicted probability and observed probability of the risk of GC. The C-index was 0.86 (95% CI: 0.79 to 0.94) with a calibration curve of better concurrence in the validation set. Conclusion The nomogram formulated was proven to be of high predictive value for GC.