Abstract: Objective   To explore the related risk factors of postoperative venous thromboembolism (VTE) in patients with gastric cancer,establish a prediction model and verify the predictive value of the model. Methods   160 gastric cancer patients who underwent radical surgery at the First Affiliated Hospital of Hainan Medical College from January 2019 to June 2021 were included as the modeling group,167 cases as validation group.Their clinicopathological data were collected.All modeling group patients were divided into VTE group and N-VTE group according to the occurrence of VTE within 6 months after operation.The clinicopathological factors of the two groups were analyzed by univariate analysis.Then,the statistically significant indexes in the univariate analysis were substituted into the multivariate logistic regression model for multivariate analysis to obtain the independent risk factors affecting the postoperative VTE of patients with gastric cancer.The independent risk factors obtained based on the results of multivariate analysis were combined β Value,assign scores to independent risk factors according to the principle of nomogram,construct the nomogram model,draw the nomogram with R software,internal and external validation of nomogram model with Bootstrap method and calibration curve,calculate the discrimination evaluation Index C index,and evaluate the calibration ability of the prediction model through goodness of fit (H-L). Results   160 modeling group patients with gastric cancer underwent radical gastrectomy.According to the occurrence of VTE within 6 months after operation,they were divided into VTE group (23 cases) (14.38%) and N-VTE group (137 cases) (85.62%).Multivariate analysis showed that the age of 60 years old,the diameter of the lesion was more than 5cm,the stage of diabetes,the TNM/T stage was 3-4,and the lymph node metastasis was the independent risk factors affecting the postoperative VTE of patients with gastric cancer (P<0.05).Construct nomogram:P=1/(1+e-X),X=1.885×Age (≥ 60 years=1,< 60 years=0)+2.051×Diabetes mellitus (=1,no =0) +2.646×Lesion diameter (≥ 5 cm=1,<5 cm=0) + 2.952 × TNM/T stage (stage 1-2 = 0,stage 3-4 = 1) + 0.694 × Lymph node metastasis (yes = 1,no = 0)-0.436.The C index of nomogram model was 847 (95%CI:0.784-0.932) and 0.832(95%CI:0.772-0.910).H-L test showed that the predicted value of postoperative VTE in patients with gastric cancer was in good agreement with the actual value (P>0.05). Conclusion   A nomogram model for predicting the risk of postoperative VTE in patients with gastric cancer was established.It was verified that the model can accurately predict the risk of postoperative VTE in patients with gastric cancer.

Key words: gastric cancer;venous thromboembolism, prediction model