Answer and Discussion of Quiz Set: N-024

3.    Which of the following features is true about glioblastomas?

A.  Secondary glioblastomas develop in older patients compared to primary glioblastoma

B.  T53 mutation is uncommon

C.  Presence of pseudopalisading necrosis is a worse prognostic sign

D.  The 5 years survival rate for glioblastoma patient of all ages is about 20%

E.  Epidermal growth factor receptor (EGFR) amplication is common in older patients

Answer and Discussion: The answer is (E). Glioblastoma is a tumor of grave prognosis. The survival for younger patient is, in general, better than older patient. According to a study in Switzerland and Canada, less than 20% of patients survived more than one year and only 3% of the patients survive more than 3 years ^1,2. Necrosis, whether it is pseudopalisading or not, is not a prognostic factor. Secondary glioblastoma refer to those glioblastomas that arise from a preexisting low-grade glioma. Secocndary glioblastomas often arise in younger patient than the de novo type of glioblastomas that has no proved low-grade precursor. T53 mutation is common in glioblastomas but it is more common in seconeary glioblastomas. EGFR amplification is uncommon in patient under 35 years of age.

References:

1.   Ohgaki H, Dessen P, Jourde B, Horstmann S, Nishikawa T, Di Patre PL, Burkhard C, Schüler D, Probst-Hensch NM, Maiorka PC, Baeza N, Pisani P, Yonekawa Y, Yasargil MG, Lütolf UM, Kleihues P. Genetic pathways to glioblastoma: a population-based study. Cancer Res. 2004 Oct 1;64(19):6892-9.

2.   Ohgaki H, Kleihues P.Epidemiology and etiology of gliomas. Acta Neuropathol. 2005 Jan;109(1):93-108.