Ki-67 Expression in Breast Cancer Tissue Microarrays: Assessing Tumor Heterogeneity, Concordance With Full Section, and Scoring Methods.

Published

Journal Article

Objectives: Ki-67 has been proposed to be used as a surrogate marker to differentiate luminal breast carcinomas (BCs). The purpose of this study was to determine the utility of and best approaches for using tissue microarrays (TMAs) and Ki-67 staining to distinguish luminal subtypes in large epidemiology studies of luminal/human epidermal growth factor receptor 2 (HER2)-negative BC. Methods: Full-section and TMA (three 0.6-mm cores and two 1.0-mm cores) slides of 109 cases were stained with Ki-67 antibody. We assessed two ways of collapsing TMA cores: a weighted approach and mitotically active approach. Results: For cases with at least a single 0.6-mm TMA core (n = 107), 16% were misclassified using a mitotically active approach and 11% using a weighted approach. For cases with at least a single 1.0-mm TMA core (n = 101), 5% were misclassified using either approach. For the 0.6-mm core group, there were 33.3% discordant cases. The number of discordant cases increased from 18% in the group of two cores to 40% in the group of three cores (P = .039). Conclusions: Ki-67 tumor heterogeneity was common in luminal/HER2- BC. Using a weighted approach was better than using a mitotically active approach for core to case collapsing. At least a single 1.0-mm core or three 0.6-mm cores are required when designing a study using TMA.

Full Text

Duke Authors

Cited Authors

  • Khoury, T; Zirpoli, G; Cohen, SM; Geradts, J; Omilian, A; Davis, W; Bshara, W; Miller, R; Mathews, MM; Troester, M; Palmer, JR; Ambrosone, CB

Published Date

  • August 1, 2017

Published In

Volume / Issue

  • 148 / 2

Start / End Page

  • 108 - 118

PubMed ID

  • 28898983

Pubmed Central ID

  • 28898983

Electronic International Standard Serial Number (EISSN)

  • 1943-7722

Digital Object Identifier (DOI)

  • 10.1093/ajcp/aqx053

Language

  • eng

Conference Location

  • England