title: Comparison of proliferation indices in glioblastoma multiforme by whole tissue section vs tissue microarray.
abstract: Tissue microarrays (TMAs) reduce the amount of tissue analyzed with the assumption that protein and gene expression patterns are homogeneous throughout tumors. Many tumor types, including glioblastoma multiforme (GBM), are heterogeneous in many regards, including cell proliferation. We retrospectively compared Ki-67 labeling indices (LIs) determined by whole tissue section (WTS) vs TMA in a series of 50 GBMs from 45 patients. A paired t test indicated that the difference between average LIs obtained from a TMA vs a WTS was not significant (P = .51). There was no correlation between TMA and WTS (r = 0.042; P = .77), indicating that the methods yielded very different results in individual tumors. The Ki-67 LI did not always correlate with the tissue section in an individual tumor; however, when evaluating a large number of tumors on a TMA, the LI range and mean LI were roughly comparable with the LI range and mean LI determined from the WTS.
authors.affiliation: Division of Pathology and Laboratory Medicine, Cleveland Clinic Foundation, Cleveland, OH, USA.
authors.forename: Andres G
authors.initials: AG
authors.lastname: Chiesa-Vottero
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Rybicki
authors.forename: Richard A
authors.initials: RA
authors.lastname: Prayson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002455:Cell Division; D005260:Female; D005909:Glioblastoma / Q000473:pathology*; D016591:Histocytological Preparation Techniques; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D016612:Paraffin Embedding; D012189:Retrospective Studies
chemical_list: D019394:Ki-67 Antigen