Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. Regardless of ideal multidisciplinary treatment, including maximal surgical resection, followed by radiotherapy plus concomitant and maintenance temozolomide (TMZ), almost all patients experience tumor progression with nearly universal mortality and a median survival of less than 15 months. The addition of bevacizumab to standard treatment with TMZ revealed no increase in overall survival (OS) but improved progression-free survival (PFS). In newly diagnosed GBM, methylation of the O6-methylguanine-DNA methyltransferase (MGMT) promoter has been shown to predict response to alkylating agents, as well asgnosis. Therefore, MGMT promoter status may have a crucial role in the choice of single modality treatment in fragile elderly population. No standard of care is established in recurrent or progressive GBM. Treatment alternatives may include supportive care, surgery, re-irradiation, systemic therapies, and combined modality therapy. Despite numerous clinical trials, the identification of effective therapies is complex because of the lack of appropriate control arms, selection bias, small sample sizes, and disease heterogeneity. Tumor-treating fields plus TMZ represent a major advance in the field of GBM therapy, and should be Standards of Care in Glioblastoma Therapy 198 considered for patients with newly diagnosed GBM with no contraindications. As a disease with such a poor prognosis, treatment of GBM should go beyond improving survival and aim at preserving and even improving the quality of life of both the patient and the caregiver.

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Background: Glioblastoma (GB) is the most common malignant primary central nervous system tumor in adults. Standard-of-care therapy includes surgical resection, radiotherapy and temozolomide, but nearly all patients experience disease progression. The purpose of this study was to describe 2 cohorts of patients with recurrent GB submitted to second-line treatment with procarbazine/lomustine/vincristine (PCV) or bevacizumab/irinotecan (BI). Material and Methods: Retrospective analysis of GB patients treated in our center with PCV or BI, after progression with temozolomide, between 2004 and 2012. Results: Among 60 patients, 41 were treated with BI and 19 with PCV. According to the Macdonald criteria, the overall response rate in the BI group was 66% (n = 27) while it was 11% (n = 2) in the PCV group. The median progression-free survival was 5 and 3 months in the BI and PCV group, respectively. The median overall survival (OS) since second-line chemotherapy was 9 months in the BI group and 5 months in the PCV group. The latter group had a worse toxicity profile (grade 3-4: 52.6% vs. 22.0%; grade 1-2: 89.5% vs. 68.3%). Conclusions: The BI cohort had higher response rates, almost twice the OS and a lower degree of toxicity in contrast to the PCV group. The small number of patients and historical cohorts limits these comparisons.

Abstract. Glioblastoma (GBM) is the most common and aggressive primary brain tumor. The identification of novel molecular prognostic markers of GBM has recently been an area of great interest in neuro-oncology. The methylation status of the MGMT gene promoter is currently a promising molecular prognostic marker, but some controversial data have precluded its clinical use. We analyzed MGMT methylation by methylation-specific PCR in 90 GBM patients from four Portuguese hospitals, uniformly treated with radiotherapy combined with concomitant and adjuvant temozolomide (Stupp protocol). The Kaplan-Meier method was used to construct survival curves, and the log-rank test and a Coxregression model were used to analyze patient survival. The methylation status of MGMT was successfully determined in 89% (80/90) of the tumors. The frequency of tumoral MGMT promoter methylation was 47.5%. The median overall survivals (OSs) were 16 months (95% CI 12.2-19.8) and 13 months (95% CI 13.3-18.7) for patients whose tumors had a methylated or unmethylated MGMT, respectively. Univariate and multivariate analyses did not show any statistically significant association between MGMT methylation status and patient OS (P=0.583 by the log-rank test; P=0.617 by the Cox-regression test) or progression-free survival (P=0.775 by the log-rank test; P=0.691 by the Cox-regression test). None of the patient clinical features were significantly correlated with survival. This is the first study to report the frequency of MGMT methylation among Portuguese GBM patients. Our data did not show statistically significant associations between MGMT promoter methylation and the outcome of GBM patients treated with temozolomide. Additional robust prospective studies are warranted to clarify whether the MGMT status should be used in clinical decisions.

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