Adherence to combinatorial treatments are important predictors of improved long-term outcomes for patients with glioblastoma (GB); however, factors associated with refusal of surgery, chemotherapy, or radiotherapy (RT) by patients with GB have not been studied. The National Cancer Database was queried from 2004 to 2018 to identify patients with a primary diagnosis of GB who underwent surgical resection alone or followed by either RT or chemotherapy. Adult patients who voluntarily rejected a physician's recommendations for 1 or more treatment were selected. Multivariable regression was used to identify factors associated with rejection of surgical resection, chemotherapy, and RT. Patients receiving treatment were 3:1 propensity score matched to those rejecting treatment and median overall survival (OS) was compared. 58,788 patients were included in the analysis. Factors associated with voluntary refusal of GB treatment included: old age, nonprivate insurance, female sex, Black race, comorbidities, treatment at a nonacademic facility, and living 55+ miles away from a treatment facility (P < 0.05). On propensity matched analysis, refusal of surgery conferred a 4 month decrease in OS (P < 0.001), RT an 8 month decrease in OS (P < 0.001), and chemotherapy a 7 month decrease in OS (P < 0.001). In patients with GB, age, sex, race, nonprivate insurance, medical comorbidities, distance from treatment facility, and geographic location were associated with refusal of surgery, postsurgical RT, and chemotherapy. In addition, treatment refusal had a significant impact on OS length.
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