Decreasing radiation therapy utilization in adult patients with glioblastoma multiforme: a population-based analysis.

BACKGROUND: The purpose of this study was to assess what factors influence radiation therapy (RT) utilization in patients with glioblastoma and to ascertain how patterns of care have changed over time.

METHODS: A total of 9103 patients with supratentorial glioblastoma in the Surveillance, Epidemiology, and End Results (SEER) database from 1973 to 2006 were analyzed. Demographic information was obtained, including age, sex, race, year of diagnosis, and marital status. Treatment characteristics included receipt of RT and surgical resection.

RESULTS: In total, 76.8% of patients received RT, whereas 78% received resection. Patients of male sex, who were currently married, who were <65 years old, and who underwent resection were more likely to receive RT. The average annual percentage change in RT utilization in the years 1990-2006 was -0.41% (95% confidence interval [CI], -0.23 to -0.58), whereas for resection it was 0.26% (95% CI, 0.03 to 0.50). This equates to a 6.5% decrease in RT utilization and a 4.2% increase in resection during this time period. Patients treated with RT had a 2-year overall survival of 11.4%, compared with 5.2% in those not treated with RT (P < .00001). Multivariate analysis showed that younger age (continuous; odds ratio [OR], 0.97; P < .0001), marital status (OR, 1.62; P < .0001), surgical resection (OR, 1.72; P < .0001), and year of diagnosis 1998-2006 compared with 1990-1997 (OR, 0.82; P < .0001) were associated with RT utilization, whereas sex, lesion size, and race were not.

CONCLUSIONS: SEER data show a decreasing utilization of RT in patients with glioblastoma from 1990 to 2006. Patients who were older, who were unmarried, and who underwent biopsy only were less likely to receive RT.