Long-term survival after glioblastoma resection: hope despite poor prognosis factors

In spite of aggressive multimodal treatment, survival for patients with glioblastoma (GBM) remains short. Nevertheless, some patients survive much longer than expected and become long-term survival patients. The extent of resection (EoR), Karnofsky Performance Scale (KPS), age and methyl-guanine methyltransferase gene (MGMT) methylation are well-defined prognostic factors, but the characteristics of patients with long-term survival (LTS, survival of at least three years after diagnosis) has not been fully determined yet. That is the reason why we analyzed the GBM patients with LTS at our center.

We retrospectively reviewed all consecutive patients who underwent surgery for GBM between January 2002 and November 2011, including patients treated with surgical resection under neuronavigation with or without intraoperative MRI (ioMRI) and those who had stereotactic biopsy. We identified and further analyzed those patients with LTS.

A total of 127 patients underwent surgery for GBM during the study period. 101 (79.6%) of whom had surgical resection and 26 (20.4%) of whom had stereotactic biopsy. Of the 101 patients who were treated with surgical resection, 12 had LTS. After two other pathologists reviewed the patients' cases, they confirmed that 11 (11%) of the 12 patients had a GBM (female/male ratio 4.5; average age 50 years; preoperative Karnofsky Score 82%), and one patient had an anaplastic glioma. The mean survival in the LTS patients with confirmed GBM was 74 (36-150) months. Seven of the LTS patients (63.6%) had a gross total resection (GTR), including two with an additional resection after ioMRI. Three (27.3%) had a near total resection (NTR: residue ≤5%) and one (9.1%) had a partial resection. Ten (90.9%) patients had a methylation of MGMT, only two (18.8%) had an IDH1 mutation, and seven (63.6%) received a full Stupp protocol.

Among patients with a GBM who were treated with one or more resections, 11% had LTS with 90.9% with at least a near total resection (36% with ioMRI) and a methylated MGMT. 50% of the patients with a second surgery survived at least two years postoperatively. Those encouraging observations emphasize the importance of maximizing the resection by using, if possible, an intraoperative guidance method like ioMRI with an analysis of biomarkers such as MGMT and if necessary, multiple surgical procedures.