Interdisciplinary treatment of glioblastoma: analysis of prognostic factors and treatment results in unselected patients.

Abstract

Aim of the present study was to investigate survival rates of unselected patients with glioblastoma after multimodal treatment and estimation of prognostic factors. Data of 189 patients (118 men; 71 women; median age: 59 years) with histologically confirmed glioblastoma treated from 1999 to 2009 were analyzed retrospectively. Complete tumor resection was performed in 99 patients (52%), subtotal excision in 65 patients (34%), and stereotactic biopsy in 25 patients (13%). In 135 patients (71%), residual tumors were detectable in post-surgical imaging. All patients underwent three-dimensional conformal radiotherapy of the tumor region in shrinking-field technique to a total dose of 60 Gy. Beginning in 2002, 124 patients (66%) received concomitant temozolomide (TMZ) treatment, 76 patients among them were additionally treated with adjuvant TMZ. After disease progression, 74 patients underwent salvage therapy (salvage chemotherapy, n=61; local therapy, n=30). Actuarial 1- and 2- year progression-free survival (PFS) rates were 32% and 7%, overall survival (OS) rates were 54% and 22%, respectively. Without TMZ, 1- and 2- year OS rates were 47% and 11%, with concomitant TMZ 57% and 28%, and with concomitant and adjuvant TMZ 72% and 44%. In multivariate Cox proportional hazards regression models, age (p<0.001), extent of resection (p = 0.001), and TMZ (p < 0.001) were significantly associated with OS. Furthermore, a significant association between salvage therapy and improved survival was observed (p=0.020). RT with concomitant TMZ was well tolerated in the majority of patients and completed as scheduled in 78% of patients. Multimodal treatment including extensive surgical resection, radiotherapy and chemotherapy significantly improves prognosis of patients with glioblastoma and is feasible with acceptable toxicity in routine practice. To achieve optimal results, close coordination among all disciplines is required.