Correlation of histomorphologic prognostic markers and proliferative index with loss of heterozygosity 1p/19q and MGMT status in diffusely infiltrating gliomas

Abstract

LOH 1p/19qMGMT MIB-1LI a b s t r a c t Background: Loss of heterozygosity (LOH)1p/19q, and epigenetic silencing of O 6 -methylguanine-DNAmethyltransferase (MGMT ) gene, displayed promising role as predictive and prognostic markers in brain tumours. The present study correlated both with conventional histomorphologic prognostic markers and proliferative index in diffusely infiltrating gliomas (DIG). Methods:Tissues from 45 patients were evaluated for LOH1p/19q using polymerase chain reaction based microsatellite analysis; and for MGMT using immunohistochemistry. Results were correlated with age, histologic type, WHO grade, and proliferation index.Results: Mean MIB-1 LI showed significant correlation with tumour grade. MGMT-staining in grade II and IV tumours were 31.1% and 16.8%, respectively, while in DA and GBM it was 88.2% and 19.0%, respectively, which were statistically significant. Sixteen cases showed LOH 1p and/or 19q of which 10 (5 oligodendroglial, 3 GBM, AA, DA) had combined LOH; while three each showed 1p (all GBM) and 19q (2 DA and GBM) loss. In the MIB-1LI 5% and >5% groups LOH 1p and/or 19q was encountered in 6 and 10 cases, respectively. A significant inverse association was noted between LOH with MGMT. Available online at www.sciencedirect.com jo urn al ho mep age: www .e lsev ie r. co m/ lo cate/ mj afi m e d i c a l j o u r n a l a r m e d f o r c e s i n d i a 6 9 ( 2 0 1 3 ) 2 2 8 e2 3 6