Standard (60 Gy) or short-course (40 Gy) irradiation plus concomitant and adjuvant temozolomide for elderly patients with glioblastoma: a propensity-matched analysis

Int J Radiat Oncol Biol Phys. 2015 Jan 1;91(1):109-15. doi: 10.1016/j.ijrobp.2014.09.013. Epub 2014 Oct 25.

Abstract

Purpose: To evaluate 2 specific radiation schedules, each combined with temozolomide (TMZ), assessing their efficacy and safety in patients aged ≥65 years with newly diagnosed glioblastoma (GBM).

Methods and materials: Patients aged ≥65 years with Karnofsky performance status (KPS) ≥60 who received either standard (60 Gy) or short-course (40 Gy) radiation therapy (RT) with concomitant and adjuvant TMZ between June 2004 and October 2013 were retrospectively analyzed. A propensity score analysis was executed for a balanced comparison of treatment outcomes.

Results: A total of 127 patients received standard RT-TMZ, whereas 116 patients underwent short-course RT-TMZ. Median overall survival and progression-free survival times were similar: 12 months and 5.6 months for the standard RT-TMZ group and 12.5 months and 6.7 months for the short-course RT-TMZ group, respectively. Radiation schedule was associated with similar survival outcomes in either unadjusted or adjusted analysis. O(6)-methylguanine-DNA methyltransferase promoter methylation was the most favorable prognostic factor (P=.0001). Standard RT-TMZ therapy was associated with a significant rise in grade 2 and 3 neurologic toxicity (P=.01), lowering of KPS scores during the study (P=.01), and higher posttreatment dosing of corticosteroid (P=.02).

Conclusions: In older adults with GBM, survival outcomes of standard and short-course RT-TMZ were similar. An abbreviated course of RT plus TMZ may represent a reasonable therapeutic approach for these patients, without loss of survival benefit and acceptable toxicity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenal Cortex Hormones / therapeutic use
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Antineoplastic Agents, Alkylating / therapeutic use*
  • Brain Neoplasms / mortality
  • Brain Neoplasms / therapy*
  • Chemoradiotherapy / adverse effects
  • Chemoradiotherapy / methods*
  • Chemotherapy, Adjuvant / adverse effects
  • Chemotherapy, Adjuvant / methods
  • DNA Methylation
  • Dacarbazine / analogs & derivatives*
  • Dacarbazine / therapeutic use
  • Disease-Free Survival
  • Drug Administration Schedule
  • Female
  • Glioblastoma / mortality
  • Glioblastoma / therapy*
  • Humans
  • Karnofsky Performance Status
  • Male
  • O(6)-Methylguanine-DNA Methyltransferase / metabolism
  • Propensity Score
  • Radiotherapy Dosage
  • Regression Analysis
  • Retrospective Studies
  • Temozolomide
  • Time Factors
  • Treatment Outcome

Substances

  • Adrenal Cortex Hormones
  • Antineoplastic Agents, Alkylating
  • Dacarbazine
  • O(6)-Methylguanine-DNA Methyltransferase
  • Temozolomide