Hypofractionated radiotherapy with or without concurrent temozolomide in elderly patients with glioblastoma multiforme: a review of ten-year single institutional experience

The landmark Stupp study demonstrated a survival advantage with concomitant and adjuvant temozolomide (TMZ) with standard radiotherapy (RT) in glioblastoma multiforme (GBM) patients but excluded those older than 70 years. The prospective Roa study of older GBM patients treated with hypofractionated 3-week course RT demonstrated equivalence to standard 6-week course RT. Taken together, these trials suggest hypofractionated RT with TMZ may be a reasonable treatment option for elderly GBM patients. We conducted a retrospective review of GBM patients (age >= 60 years) treated with hypofractionated RT and temozolomide at our institution between 2000 and 2010. We identified 112 patients who received hypofractionated RT, with 57 receiving concurrent and adjuvant TMZ and 55 without concurrent chemotherapy. Of the 55 patients who received hypofractionated RT alone initially, 24 subsequently received TMZ as salvage treatment at time of progression. Among the concurrent RT + TMZ patients, mean age was 70 years (range 60-86), median KPS was 80 (range 30-100) and 24/57 (42%) received prior debulking surgery. Median overall survival (OS) among the RT + TMZ patients was 6.9 months (95% CI, 4.5-8.6). Patients without concurrent chemotherapy were similar in demographics (age, sex, corticosteroid use, KPS) except 34/55 (62%) were debulked (P-value 0.045.) Median OS was 9.3 months (95% CI, 5.9-11.8) (P-value 0.351). Subgroup analysis revealed patients treated with initial hypofractionated radiation with salvage TMZ had increased median OS of 13.3 months (95% CI, 9.9-19.3) (P-value 0.012). Our results suggest concurrent and adjuvant TMZ does not confer a survival benefit in elderly GBM patients. A sequential approach may be a more effective and efficient strategy by selecting responding patients who may benefit most from subsequent salvage chemotherapy.