Development and external validation of a nomogram for predicting the survival outcomes of patients with Ki-67 positive grade 4 diffuse gliomas

Abstract

Abstract Background Grade 4 diffuse gliomas is a highly malignant tumor with considerable health implications. Studies have investigated the immunohistochemical molecules associated with glioblastoma development. However, grade 4 diffuse gliomas in Ki-67 positive patients have not been conclusively investigated. Methods We retrospectively extracted data for 146 patients with Ki-67 positive grade 4 diffuse gliomas at the affiliated hospital of Qingdao University between 2020 and 2021. The data were analyzed using the R software. Statistically significant indicators were identified by COX regression analysis and used to establish the Nomogram. The nomogram was corrected by C-index, area under the curve (AUC), calibration curve and decision curve analyses (DCA). Finally, the model was externally validated using the Chinese Glioma Genome Atlas (CGGA) database. The experiment was approved by the Medical Ethics Committee of the Affiliated Hospital of Qingdao University. All methods were performed in accordance with relevant guidelines and regulations. The authors of this experiment promise that informed consent of all subjects and/or their legal guardians has been obtained for this research. Results Age, treatment and IDH were found to be significant. The models’ C-index was 0.743 while the area under the curve (AUC) value of the time-dependent ROC curve at 3- and 6-months were 0.832 and 0.829, respectively. These findings imply a good discriminatory ability. Finally, a nomogram was constructed and validated using validation and DCA curves. Conclusion Three risk factors (age, treatment and IDH) were identified to be independent prognostic factors in Ki-67 positive grade 4 diffuse gliomas patients. The model can be used to accurately assess the disease-specific survival rates of these patients and inform on treatment options.