Positive influence of partial resection on overall survival of patients with overlapping glioblastomas

Patients with overlapping glioblastomas (former known as gliomatosis cerebri according to the 2007 WHO classification) have a poor prognosis. Most of the patients undergo biopsy to confirm histopathological diagnosis. Treatment comprises chemotherapy, radiation and combination of both. We determined whether resection of the contrast enhancing tumor parts leads to a prolonged survival.

We performed a retrospective analysis and included 31 patients with overlapping glioblastomas (OG) who showed WHO IV in the initial histopathological examination. All patients fulfilled criteria of overlapping glioblastomas in the MRI according to WHO criteria (3 or more lobes were affected). We evaluated Karnofsky performance score (KPS), gender, age, IDH-1_R132H status, MGMT promotor methylation status, proliferation index, postoperative therapy, biopsy vs. partial resection and extent of resection as possible factors affecting overall survival (OAS). A matched pair analysis was performed between the biopsy and resection group on basis of age, KPS and combined radio-chemotherapy.

10 Patients underwent resection of the contrast enhancing tumor parts, 21 patients underwent stereotactic biopsy. All included patients showed contrast enhancing lesions in the MRI. Median age was 61 years in the biopsy-group and 53 in the partial resection (PR) group. We found a significant correlation between OAS and age <50 (p=0.02). Median KPS was 80 in the STX group vs. 100 in the PR group. KPS above 80 was significantly associated with longer OAS (p=0.02). Median survival was 174days in the STX group compared to 446days in the PR group (p=0.05). Also the matched pair analysis showed significant p-values for resection.

Partial resection might have a positive impact on overall survival of patients with overlapping glioblastomas (former known as gliomatosis cerebri), although the prognosis remains limited.