Prognostic factors effective on survival of patients with glioblastoma: Anadolu Medical Center experience

The aim of this study is to offer survival following radiation therapy using intensity-modulated radiotherapy or volumetric arc therapy with temozolomide in patients with glioblastoma.

Ninety-two previously treated patients with high-grade glioma (World Health Organization [WHO] grade IV) were studied in Anadolu Medical Center, Department of Radiation Oncology, between January 2006 and July 2015. The diagnosis was established by pathology in all cases. The median age was 59 years (range, 19-86 years). The median tumor diameter was 45 mm, and the rate of the multicentric tumors was 16.3%. The location of the tumor was temporal in 33.7%, parietal in 14.1%, frontal in 23.9%, occipital in 9.8%, and others in 18.5%. The gross total and subtotal resection were performed in 60.9% of the patients, partial resection in 26.1%, and only stereotactic biopsy in 13.0% of the patients.

The median overall survival (OS) was 33.01 ± 4.76 months (95% confidence interval 25.64-40.38 months). 1, 2, and 5 years OS was 74.3%, 44.3%, and 31.8%, respectively. The median progression-free survival (PFS) was 27.36 ± 3.87 months (95% confidence interval 19.82-34.89 months). 1, 2, and 5 years PFS was 62.7%, 32.6%, and 27.2%, respectively. On univariate analysis, gender, extent of surgery, tumor size, Karnofsky performance status, and tumor suppressor gene (P53) were significant predictors of OS and PFS. On multivariate analysis, gender (PFS: P = 0.006, OS: P = 0.003), extent of surgery (PFS: P = 0.004, OS: P = 0.012), P53 (PFS: P = 0.003, OS: P = 0.021), and size of tumor (PFS: P = 0.005, OS: 0.012) remained significantly associated with PFS and OS. There is no statistically significant in OS and PFS between female and male (OS: log-rank: 0.79 P = 0.375, PFS: log-rank: 0.54 P = 0.465). PSF and OS were not significantly significant with total/near total resection compared with partial resection (PSF: P = 0.46 log-rank = 0.54, OS: P = 0.340 log-rank = 0.91). Patients with P53 <50% value and patients with P53 >50% value were compared and results were not found statistically significant (PSF: P = 0.917 log-rank = 0.01, OS: P = 0.892 log-rank = 0.02). For patients with tumor size <0 mm, small tumor size did not improve the PSF and OS (PSF: P = 0.291 log-rank = 1.11, OS: P = 0.288 log-rank = 1.13).

Ninety-two previously treated patients with high-grade glioma (WHO Grade IV) were evaluated with multivariate analysis. Gender, extent of surgery, P53, and tumor size were found as prognostic factors affecting on survival.