Radiochemotherapy with temozolomide for patients with glioblastoma. Prognostic factors and long-term outcome of unselected patients from a single institution.

Background: The objective of this retrospective analysis was to assess long-term outcome and prognostic factors of unselected patients treated for glioblastoma (GB) at a single center with surgery, standard radiotherapy (RT), and concomitant temozolomide (TMZ). From 1999-2005, the institutional protocol included surgery and RT with TMZ. From 2005 on, adjuvant TMZ was routinely added.

Patients And Methods: Between April 1999 and September 2009, 181 patients with GB were treated with RT (60 Gy in 30 fractions) and concomitant TMZ (75 mg/m2/day throughout RT). Biopsy only had been performed in 53 patients (29.3%), 128 patients (70.7%) had undergone resection, which was complete based on postoperative MRI in 51 patients (28.2%). Adjuvant TMZ was applied in 67 of 181 patients (37%).

Results: Median overall survival (OS) and progression-free survival (PFS) were 15.0 (95% CI, 13.1-16.8) and 7.2 months (95% CI, 5.9-8.5), respectively. After complete resection, partial/subtotal resection and biopsy, median OS was 23.20, 14.75, and 7.89 months (p<0.001), respectively. In multivariate Cox proportional hazards regression models, extent of resection (p<0.0001), Karnofsky's performance score (p<0.0001) and adjuvant TMZ (p=0.001) were significant independent prognostic factors for OS. RT with concomitant TMZ was well tolerated in the majority of patients and could be completed as scheduled in 146 patients (80.7%), while 11 patients (6.1%) discontinued RT. Another 35 patients (19.3%) interrupted concomitant chemotherapy.

Conclusion: RT with concomitant TMZ is a feasible regimen with acceptable toxicity in routine practice. Our data are compatible with a beneficial effect of adjuvant TMZ on OS and PFS.