Glioblastoma multiforme (GBM) Patients generally have a dismal prognosis, with median survival of 10-12 months. GBM with long-term survival (LTS) of ³ 5 years is rare, and no definite markers indicating better prognosis have been identified till date. The present study was undertaken to evaluate GBMs with LTS in order to identify additional correlates associated with favourable outcome.
The cases were evaluated for relevant clinicopathological data, proliferation index and expression of tumortumour suppressor gene (
p53 ), cyclin-dependant kinase-inhibitors (
p27 and
p16 ) and epidermal growth factor receptor (EGFR) proteins.
Six cases of GBM with LTS with an average survival of 9 years (range 5-15 years) were identified. All were young patients with mean age of 27 years (range 8-45 years). Histology of three cases was consistent with conventional GBM, while two showed prominent oligodendroglial component admixed with GBM areas. One was a giant cell GBM, which progressed to gliosarcoma on recurrence. The mean MIB-1LI was 12% (range 6-20%).
p53 was immunopositive in 4 out of 5 cases. EGFR and
p27 were immunonegative in all, whereas
p16 was immunonegative in 3 out of 5 cases.
Currently, in the absence of specific molecular and genetic markers, GBM in young patients should be meticulously evaluated for foci of oligodendroglial component and/or giant cell elements, in addition to proliferative index and
p53 expression, since these probably have prognostic connotations, as evident in this study. The role of
p16 and
p27 however needs better definition with study of more number of cases.
