Summary and analysis of clinical features and prognosis in pediatric gliomas based on the SEER database

Objective Based on the SEER (Surveillance, Epidemidogy, and End Results) database, this study retrospectively summarized clinical characteristics, and explored prognostic factors of patients with different histological types of pediatric gliomas. Methods A total of 7759 pediatric patients with gliomas confirmed by histopathology from the SEER database from 2000 to 2015 were included in the study and were classified into pilocytic astrocytoma, medulloblastoma, ependymoma, glioblastoma and other gliomas according to histological classification. Kaplan⁃Meier survival analysis was utilized to compare 5⁃year survival rates. Univariate log⁃rank test and multivariate forward selection Cox regression analysis were used to screen the factors related to survival and prognosis. Results According to histological classification, 7759 patients were divided into 2585 cases of pilocytic astrocytoma (33.32%), 2061 cases of medulloblastoma (26.56%), 777 cases of ependymoma (10.01%), 443 cases of glioblastoma (5.71%) and 1893 cases (24.40%) of other types of gliomas. The differences of gender (χ2 = 60.390, P = 0.000), age distribution (χ2 = 600.318, P = 0.000), tumor size (χ2 = 90.773, P = 0.000), location (χ2 = 2117.948, P = 0.000) and pathological grade (χ2 = 1233.506, P = 0.000) in different histological types were statistically significant respectively. Among them, medulloblastoma (60.89%, 1255/2061) and glioblastoma (57.56%, 255/443) were more likely to occur in male and school age was the peak age of onset (35.48%, 2753/7759); pilocytic astrocytoma and medulloblastoma were mainly small tumors (31.30%, 809/2585; 33.77%, 696/2061) and more likely occurred in cerebellum (42.24%, 1092/2585; 59.58%, 1228/2061); while ependymoma and glioblastoma were larger (32.43%, 252/777; 29.57%, 131/443) and were occurred in supratentorial and cerebral ventricles (36.81%, 286/777; 65.91%, 292/443); only pilocytic astrocytoma was mainly of low grade (24.06%，622/2585). Survival analysis showed 5⁃year survival rates of patients with pilocytic astrocytoma, medulloblastoma, ependymoma and glioblastoma were 97.41% (2518/2585), 64.39% (1327/2061), 76.83% (597/777) and 16.25% (72/443) respectively, and difference was statistically significant (χ2 = 2145.672, P = 0.000). Univariate log ⁃ rank test and multivariate Cox regression analysis showed prognostic factors of different histological types were not consistent, including age at diagnosis, tumor size and location, pathological grade, surgical resection and radiotherapy. Accept pilocytic astrocytoma, surgical resection of patients with medulloblastoma, ependymoma and glioblastoma had positive significance for survival and prognosis; radiotherapy can reduce risk of death in medulloblastoma, but it might increase risk of death in pilocytic astrocytoma. Conclusions Pilocytic astrocytoma is most common pediatric glioma with best prognosis, and glioblastoma has a relatively low incidence with poor prognosis. Demographic information, tumor characteristics and treatment options are all predictive factors for survival and prognosis of children with glioma. Surgical resection can reduce risk of death in children with gliomas of various histological types except pilocytic astrocytoma. Radiotherapy can reduce risk in medulloblastoma, however, it may increase risk of death in pilocytic astrocytoma. doi：10.3969/j.issn.1672⁃6731.2021.03.005