Effects of concurrent topotecan and radiation on 6-month progression-free survival in the primary treatment of glioblastoma multiforme.

PURPOSE: To report a prospective, randomized, Phase II trial of radiotherapy with and without topotecan for the treatment of glioblastoma.

PATIENTS AND METHODS: Inclusion criteria were histology of glioblastoma, age <60 years, and Eastern Cooperative Oncology Group status 0-2. Patients were stratified according to recursive partitioning analysis class, center, and enzyme-inducing antiepileptic medication. Magnetic resonance imaging scans, neurologic examinations, and quality of life assessments were done every 3 months. The primary endpoint was the progression-free survival rate at 6 months (6-m-PFS). This trial was designed as an exploratory, randomized, Phase II trial with an accrual of 140 patients to detect a difference of 15-20% in 6-m-PFS. An interim analysis was scheduled after 60 patients. Median follow-up was 14 months (range, 1-50 months).

RESULTS: The 6-m-PFS was 56% and 40% for patients with and without topotecan, respectively. This benefit disappeared within 2 months. Mean (range) progression-free survival time was 8 (5-10.9) months and 6.7 (4-9.5) months for patients with and without topotecan, respectively. The corresponding 2-year-overall survival rates were 28% vs. 22% (nonsignificant difference), and mean (range) survival time was 20.7 (13.9-27.5) months vs. 18.9 (13.5-24.4) months (nonsignificant difference).

CONCLUSIONS: A slight but measurable increase of 16% was detected in 6-m-PFS for patients receiving topotecan with radiation as compared with patients having radiotherapy alone. These data might support further investigations into topotecan for the treatment of glioblastoma.