Improved 3-year survival rates for glioblastoma multiforme are associated with trends in treatment: analysis of the national cancer database from 2004 to 2013.

PURPOSE: Glioblastoma multiforme (GBM) is a common and aggressive malignancy associated with poor prognosis. Characteristics and treatment of long-term survivors are of particular interest in efforts to improve outcomes. Therefore, the objective of this study was to examine trends and prognostic factors for 3-year survival from a national database. METHODS: The National Cancer Database (NCDB) was queried for patients diagnosed with cranial GBM from 2004 to 2013 and with 3-year follow-up. Trends in 3-year and overall survival, patient characteristics, tumor properties, and treatment modalities were examined. Multivariable logistic regression was utilized to investigate the association of these factors with 3-year survival. Predictor importance analysis was conducted using a metric defined as Wald χ2 penalized by degrees of freedom. RESULTS: A total of 88,919 GBM patients with 3-year follow-up were identified. Overall, 8757 (9.8%) patients survived ≥ 3 years. Three-year survival significantly improved from 8.0 to 10.5% (p < 0.001) from 2004 to 2013. Trimodal treatment administration also significantly increased from 38.7 to 55.9% (p < 0.001). During this span, patients increasingly presented as older (p = 0.040), without private insurance (p < 0.001), and with a higher comorbidity index (p < 0.001). On multivariable regression, factors such as trimodal treatment (p < 0.001), younger age (p < 0.001), and MGMT methylation (p < 0.001) were significantly associated with increased odds of 3-year survival. Predictor importance analysis indicated that MGMT methylation, age, and treatment modality were the most significant relative determinants of 3-year survival. CONCLUSION: These findings illustrate an improved 3-year survival rate for GBM patients from 2004 to 2013 with a concurrent increase in trimodal treatment administration despite more adverse patient presenting characteristics.