Prediction of Ki-67 expression and malignant potential in gastrointestinal stromal tumors: novel models based on CE-CT and serological indicators

Background and study aims To identify more reliable imaging and serological indicators for predicting Ki-67 expression and malignant potential in gastrointestinal stromal tumors, as well as to develop a preoperative prediction model with clinical utility. Patients and methods Patients with gastrointestinal stromal tumors diagnosed at the First Affiliated Hospital of Jinzhou Medical University between May 2018 and May 2024 were retrospectively analyzed. Univariate logistic analyses, multivariate logistic analyses, stepwise regression analyses, and LASSO regression analyses were utilized to identify Ki-67 high expression and high malignant potential risk factors for GIST. Prediction models were then constructed and nomograms developed. Results Tumor diameter and EVFDM were found to be closely associated with Ki-67 expression, while tumor volume and IBSC were closely related to malignant potential. The two-way stepwise regression model demonstrated high accuracy and good fit. The AUCs for the Ki-67 expression model in the training and validation groups were 0.865 (95%CI 0.807-0.922) and 0.784 (95%CI 0.631-0.937) respectively. The AUCs for the malignant potential model in the training and validation groups were 0.950 (95%CI 0.920-0.980) and 0.936 (95%CI 0.867-1.000) respectively. Conclusion The maximum diameter, growth pattern, EVFDM, peritumoral vessels, PLR, OPNI are correlated with Ki-67 high expression. Volume, contour, ulcer, IBSC and OPNI are correlated with malignant potential of gastrointestinal stromal tumors; Preoperative models developed using enhanced CT imaging can respectively predict the malignant potential and Ki-67 expression of GIST. Furthermore, when combined with serological indicators, the predictive accuracy of this model can be further enhanced.