Sampling strategies for tissue microarrays to evaluate biomarkers in ovarian cancer.

Journal Article (Journal Article)

INTRODUCTION: Tissue microarrays (TMA) enable rapid analysis of biomarkers in large-scale studies involving archival tumor specimens, however, their utility in heterogeneous tumors such as ovarian cancer is limited. METHODS: In this study, immunohistochemical analysis was done on TMAs comprised of epithelial ovarian cancer (EOC) to estimate the prevalence of loss of expression of three mismatch repair proteins. TMAs were initially created using cores sampled from the center of donor tissue blocks from 59 EOC cases. Full sections were subsequently created and levels of expression were compared between tissues sampled from the central portion versus the periphery. Follow-up analyses were done by obtaining cores from the periphery of up to five additional donor blocks per case. A linear mixed model for each protein was used to investigate differences between results from the initial and follow-up blocks. RESULTS: In the original TMAs created using centrally sampled cores, loss of mismatch repair expression was noted in 17 (29%) of the 59 cases. By comparison, analyses from peripherally sampled cores revealed loss of expression in only 6 of these 17 cases. For each protein, significant differences (P < 0.05) were detected between results from the initial donor block and the majority of the follow-up blocks. CONCLUSIONS: Our investigations, based on EOC, suggest that sampling variability in protein expression may result when TMAs are used. Thus, at least for EOC, it is important to preferentially sample from the periphery of tumor blocks where exposure to tissue fixatives is optimal.

Full Text

Duke Authors

Cited Authors

  • Permuth-Wey, J; Boulware, D; Valkov, N; Livingston, S; Nicosia, S; Lee, J-H; Sutphen, R; Schildkraut, J; Narod, S; Parker, A; Coppola, D; Sellers, T; Pal, T

Published Date

  • January 2009

Published In

Volume / Issue

  • 18 / 1

Start / End Page

  • 28 - 34

PubMed ID

  • 19124477

Pubmed Central ID

  • PMC2664171

International Standard Serial Number (ISSN)

  • 1055-9965

Digital Object Identifier (DOI)

  • 10.1158/1055-9965.EPI-08-0713


  • eng

Conference Location

  • United States