Nomograms for pre- and postoperative prediction of long-term survival among proximal gastric cancer patients: A large-scale, single-center retrospective study

Abstract

BACKGROUND The incidence of proximal gastric cancer (GC) is increasing, and methods for the prediction of the long-term survival of proximal GC patients have not been well established. AIM To develop nomograms for the prediction of long-term survival among proximal GC patients. METHODS Between January 2007 and June 2013, we prospectively collected and retrospectively analyzed the medical records of 746 patients with proximal GC, who were divided into a training set (n = 560, 75%) and a validation set (n = 186, 25%). A Cox regression analysis was used to identify the preoperative and postoperative risk factors for overall survival (OS). RESULTS Among the 746 patients examined, the 3- and 5-year OS rates were 66.1% and 58.4%, respectively. In the training set, preoperative T stage (cT), N stage (cN), CA19-9, tumor size, ASA core, and 3- to 6-mo weight loss were incorporated into the preoperative nomogram to predict the OS. In addition to these variables, lymphatic vascular infiltration (LVI), postoperative tumor size, T stage, N stage, blood transfusions, and complications were incorporated into the postoperative nomogram. All calibration curves used to determine the OS probability fit well. In the training set, the preoperative nomogram achieved a C-index of 0.751 [95% confidence interval (CI): 0.732-0.770] in predicting OS and accurately stratified the patients into four prognostic subgroups (5-year OS rates: 86.8%, 73.0%, 43.72%, and 20.9%, P < 0.001). The postoperative nomogram had a C-index of 0.758 in predicting OS and accurately stratified the patients into four prognostic subgroups (5-year OS rates: 82.6%, 74.3%, 45.9%, and 18.9%, P < 0.001). CONCLUSION The nomograms accurately predicted the pre- and postoperative long-term survival of proximal GC patients.