Prognostic Nomogram For Adult Patients With Astrocytoma

Objective To explore the relationship between prognostic factors and survival of adult patients with astrocytoma in diffuse glioma after the fifth edition of the World Health Organization Classification of Central Nervous System Tumors(WHO CNS5)in 2021,and establish a Nomogram prediction model that can effectively predict the survival and prognosis of these patients.Necessary clinical intervention should be carried out on the important factors that can improve the prognosis of these patients,in order to improve the survival time of patients and better serve the clinic.Methods Clinical data of glioma patients from the Chinese Glioma Genome Atlas(CGGA)database were collected as the training set(clinical data updated at 2022-01-04),and clinical data of patients pathologically confirmed as glioma after surgery from the General Hospital of Ningxia Medical University were collected as the validation set(2015-2022).Chi-square test(x2)was applied to analyze the data composition of the training set and validation set.Meanwhile,Kaplan-Meier survival curve was applied to analyze the relationship between the covariables in the training set and the survival period of patients.Univariate and multivariate COX regression analysis was used to analyze the risk factors affecting the survival period of these patients.R software was used to build the Normograph prediction model,and the consistency index(C-index)and calibration curve were used for internal and external verification,so as to evaluate the accuracy of Normograph prediction model.Results A total of 845 adult patients with diffuse glioma(including 332 patients with astrocytoma)from the CGGA database were included as the training set,and 221 patients with diffuse glioma(including 90 patients with astrocytoma)from Ningxia Medical University General Hospital were included as the verification set.The ratio of training set to verification set is close to 8∶2.For adult astrocytoma,there was no significant difference in the basic clinical characteristics between the training set and the validation set except the age of diagnosis and chemotherapy(P > 0.05).The median survival time of WHO grade 2,3 and4 astrocytoma was 64.13 months,32.77 months and 13.77 months,and the 5-year survival rate was 76.74%,32.77% and 19.05%,respectively.K-M curve shows that WHO grade of tumor is an important prognostic factor for astrocytoma patients.Age,gender,radiotherapy and chemotherapy were all P > 0.05,without statistical significance.Adult astrocytoma were further divided into high-grade group and low-grade group.K-M curve was applied to verify the postoperative radiotherapy and chemotherapy of high-grade astrocytoma patients.All P <0.05 showed a positive correlation with the prognosis of patients.After that,we further studied adult patients with diffuse glioma as a whole: K-M curves showed that WHO grade,histology,age,radiotherapy,IDH status,and 1p/19 q combined deletion were important prognostic factors for these patients.Multivariate COX regression analysis showed that WHO grade,radiotherapy,chemotherapy and 1p/19 q combined deletion were independent prognostic factors for adult patients with diffuse glioma(all P < 0.001).The Nomogram prediction model was constructed based on the above factors in the training cohort of 845patients(the prediction model for astrocytoma patients was shown in the nomogram of adult diffuse glioma patients),and the C-index was 0.758 and 0.822,respectively.The calibration curves of 1,3 and 5 years show that the prediction results of Normograph are in good agreement with the observation results of the training cohort and the verification cohort.Conclusion The results of this study showed that the survival of oligodendroblastoma patients with the same WHO grade was significantly better than that of astrocytoma,which in turn was better than glioblastoma.Multivariate COX regression analysis showed that WHO low grade,IDH mutation,radiotherapy,chemotherapy and 1p/19 q combined deletion were all influential factors for good prognosis of adult diffuse glioma patients.The prediction model based on Normograph has good predictive efficacy,which is convenient for clinicians to preliminarily evaluate the 1,3,and 5-year survival rate of these patients,and provides a basis for the implementation of individualized treatment.