VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF) EXPRESSION FOR ANGIOGENIC ASSESSMENT IN GLIOMAS

Abstract

Glial neoplasms constitute the majority of primary neoplasms of the central nervous system. TI1is group of tumours includes those of astrocytic, oligodendroglia!, and ependymal differentiation as well as tumours of mixed composition (e.g. Oligoastrocytomas).

Astrocytic tumours, the most common type of glial neoplasms, can be separated by histological grade into astrocytomas , anaplastic astrocytomas, and glioblastoma multiforme, based on increasing malignant phenotype.

Gliomas, particularly astrocytic tumours, are recognised as highly vascular tumours with potent angiogenic activity.

Angiogenesis is defined as the sprouting of capillaries from pre-existing vessels. Indirect measures of angiogenesis, such as measuring tl1e levels of angiogenic factors, may be clinically useful as diagnostic markers and prognostic indicators.

Ncovascularization is a neuropathological hallmark m high grade gliomas and angiogenic factors may play an important role in malignant tumour progression.

llJcrcforc, 77 cases of gliomas [68 astrocytomas (88%), 4 oligodendrogliomas (5%) and 5 ependymomas (7%) ]were collected from department of patlmlogy, Mayo Clinic, Rochester, Minnesota, U.S.A, during the years 1998-2000 and were investigated immmmhistochemically for expression of vascular