months, and 6 months, respectively. Age, MK-8669 Ridaforolimus KPS, sex, total dose of radiotherapy, radiotherapy fraction dose, and pseudoprogression were not significant prognostic factors for PFS. The median OS was 22 months, the 3 year OS rate was 22% in 93 patients, and the 5 year OS rate was 15%. Age and MGMT gene promoter methylation status were significant prognostic factors in both univariate and multivariate analyses. The median survival time and 2 year survival rates were 30 months and 57% in patients younger than 50 years and 18 months and 27% in patients older than 50 years, respectively. Patients who underwent GTR or STR showed a median survival of 23 months and a 2 year survival rate of 38%. However, patients who received partial resection or biopsy only showed a median survival of 15 months and a 2 year survival rate of 33%.
The median survival times of the methylated, unmethylated, and unknown groups were 29 months, 20 months, and 14 months, respectively. In the 35 patients with methylated MGMT promoters, the 3 year and 5 year survival rates were 43% and 31%, respectively. KPS, sex, total dose of radiotherapy, fraction dose of radiotherapy, and pseudoprogression were not significant prognostic factors. Long term survivors were more frequently seen in the methylated group. To assess the impact of radiation dose and chemotherapy regimen, 90 patients were divided into three groups according to total dose of radiation and TMZ regimens: 60 Gy and the current TMZ regimen, over 60 Gy and the current TMZ regimen, and over 60 Gy and inconsistent TMZ regimen.
Three patients with low total dose of radiation were excluded. There was no statistically significant difference in OS among the three groups. Patients were classified according to the three most significant prognostic factors in our current study, and treatment outcome was analyzed. The 6 patients with combined prognostic factors of having a methylated MGMT gene, age 50 years, and total/subtotal resections are all alive 38 to 77 months after operation. However, the median OS in the 8 patients with an unmethylated MGMT gene, age 50 years, and less than a subtotal resection was 13.2 months. Discussion Age, performance status, Mini Mental Status Examination, extent of resection, detection of pseudoprogression, tumor location, and no corticosteroid treatment at baseline were considered prognostic factors in previous reports.
Among these, age, performance status, and extent of resection are the most consistently reported prognostic factors for patients with GBM. In this study, age and MGMT gene promoter methylation were independent prognostic factors for OS, and extent of resection and MGMT gene promoter methylation were independent prognostic factors for PFS. Sex, KPS, total dose of radiotherapy, radiation necrosis, and pseudoprogression did not show significant correlation with patient survival. The EORTC trial 26981/22891 and NCIC trial CE.3 was a prospective, randomized study to compare radiotherapy alone and radiotherapy plus TMZ in a total of 573 patients from 85 centers. Hegi et al. evaluated the MGMT methylation status in a total of 307 of 573 patients, and they reported that the median OS was 21.7 months in patients with a methylated MGMT gene promoter and 12.7 months in patients with an unmeth