Radiotherapy with and without temozolomide in elderly patients with glioblastoma

The optimal treatment for elderly patients (age ≥ 70 years) with glioblastoma (GBM) remains controversial. We conducted a retrospective analysis in 43 consecutive elderly patients with glioblastoma who either underwent radiotherapy (RT) or radiotherapy plus concomitant temozolomide (TMZ).

A total of 43 patients (≥ 70 years of age, median age 75.8 years) with newly diagnosed glioblastoma and a Karnofsky performance status (KPS) ≥ 70 were treated with RT alone (median 60 Gy in 2 Gy single fractions) or RT plus TMZ at a dose of 75 mg/m(2) per day. The two groups were well-balanced; univariate (log-rank test) and multivariate Cox proportional hazards analysis were used to identify relevant prognostic factors.

The median overall survival (mOS) of the entire patient cohort was 264 days (8.8 months) and the median progression-free survival (PFS) was 192 days (6.4 months). The factors age, sex, previous surgery, KPS, and concomitant use of TMZ had no significant influence on OS/PFS; multivariate analysis was performed to obtain adjusted hazard ratios. TMZ use resulted in a trend toward poorer overall survival when applied concomitantly (314 days compared to 192 days within the TMZ group, p = 0.106). The subgroup analysis revealed that TMZ use resulted in significantly worse survival rates in patients with KPS70 (p = 0.027), but for patients with KPS80 this difference was not detectable.

TMZ should only be used carefully in elderly patients with unfavorable KPS. In this patient cohort, radiotherapy alone is a reasonable option. Standard RT plus concomitant TMZ may be an advantageous treatment option for elderly patients with newly diagnosed glioblastoma who present with good prognostic factors.