Clinical Features Associated with the Efficacy of Chemotherapy in Patients with Glioblastoma (GBM): A Population-based Study

Abstract

BackgroundGlioblastoma (GBM) is a highly malignant brain tumor with poor survival and prognosis. Randomized trials have demonstrated that chemotherapy improves survival in patients with GBM. This study aims to examine the clinical characteristics that are potentially associated with the efficacy of chemotherapy and the risk factors of GBM.MethodsA total of 25,698 patients diagnosed with GBM were identified between 2004 and 2015 from the Surveillance, Epidemiology, and End Results (SEER). The clinical and demographic variables between groups were examined by Student's t-test and Pearson's chi-squared test. GBM-specific survival (GBMSS) and overall survival (OS) were evaluated using the Kaplan-Meier method with the log-rank test. Univariable and multivariable analyses were also performed using the Cox proportional hazard model to identify statistically significant prognostic factors.ResultsPatients who received chemotherapy had better overall survival (median OS 13 vs. 3 months, HR=1.9224, 95%CI 1.8571-1.9900, p<0.0001) and better GBMSS (median GBMSS of 12 vs. 3 months, HR=1.9379, 95%CI 1.8632-2.0156, p<0.0001) compared with patients who did not. Further subgroup analysis revealed that among patients who underwent chemotherapy, those who were younger, with the well-differentiated tumor, with a supratentorial tumor, received surgery or radiotherapy had both improved OS and GBMSS. Age, race, tumor grade, tumor location, tumor size, and treatments were identified as independent prognostic factors by multivariable analyses for patients with glioblastoma. ConclusionPatients with GBM who were younger (<65 years), with the well-differentiated tumor, underwent surgery or radiotherapy can benefit more from chemotherapeutic regimens. Age, race, tumor size, tumor location, tumor grade, surgery, radiotherapy, and chemotherapy were factors associated with the prognosis of patients with GBM.