Incorporating microarray assessment of HER2 status in clinical practice supports individualised therapy in early-stage breast cancer

Kathleen A Grant; Fredrieka M Pienaar; Karen Brundyn; Gillaume Swart; George S Gericke; Ettienne J Myburgh; Colleen A Wright; Justus P Apffelstaedt; Maritha J Kotze

doi:10.1016/j.breast.2014.12.006

Incorporating microarray assessment of HER2 status in clinical practice supports individualised therapy in early-stage breast cancer

Breast. 2015 Apr;24(2):137-42. doi: 10.1016/j.breast.2014.12.006. Epub 2015 Jan 10.

Authors

Kathleen A Grant¹, Fredrieka M Pienaar², Karen Brundyn³, Gillaume Swart³, George S Gericke⁴, Ettienne J Myburgh⁵, Colleen A Wright⁶, Justus P Apffelstaedt⁷, Maritha J Kotze⁸

Affiliations

¹ Division of Anatomical Pathology, Department of Pathology, Faculty of Medicine and Health Sciences, University of Stellenbosch, Tygerberg, South Africa; Department of Biomedical Sciences, Faculty of Health and Wellness, Cape Peninsula University of Technology, Bellville, South Africa.
² GVI Oncology, Panorama Medi-Clinic, Panorama, South Africa.
³ Pathcare N1-City, Goodwood, South Africa.
⁴ Ampath, Centurion, Pretoria, South Africa.
⁵ Panorama Medi-Clinic, Panorama, South Africa.
⁶ Division of Anatomical Pathology, Department of Pathology, Faculty of Medicine and Health Sciences, University of Stellenbosch, Tygerberg, South Africa; National Health Laboratory Service, Port Elizabeth, South Africa.
⁷ Department of Surgery, Faculty of Medicine and Health Sciences, University of Stellenbosch, Tygerberg, South Africa.
⁸ Division of Anatomical Pathology, Department of Pathology, Faculty of Medicine and Health Sciences, University of Stellenbosch, Tygerberg, South Africa. Electronic address: maritha@sun.ac.za.

PMID: 25586984
DOI: 10.1016/j.breast.2014.12.006

Abstract

Accurate determination of human epidermal growth factor receptor-2 (HER2) status is essential for optimal selection of breast cancer patients for gene targeted therapy. The analytical performance of microarray analysis using TargetPrint for assessment of HER2 status was evaluated in 138 breast tumours, including 41 fresh and 97 formalin-fixed paraffin embedded (FFPE) specimens. Reflex testing using immunohistochemistry/in situ hybridization (IHC/ISH) in four discordant cases confirmed the TargetPrint results, achieving 100% agreement regardless of whether fresh tissue or FFPE specimens were used. One equivocal IHC/ISH case was classified as HER2-positive based on the microarray result. The proven clinical utility in resolving equivocal and borderline cases justifies modification of the testing algorithm under these circumstances, to obtain a definitive positive or negative test result with the use of microarrays. Determination of HER2 status across three assay platforms facilitated improved quality assurance and led to a higher level of confidence on which to base treatment decisions.

Keywords: Analytical validation; Breast cancer; HER2 status; MammaPrint prescreen algorithm; Quality assurance; TargetPrint microarray.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Algorithms
Biomarkers, Tumor / metabolism*
Breast Neoplasms / metabolism*
Breast Neoplasms / pathology
Breast Neoplasms / therapy
Carcinoma, Ductal, Breast / metabolism*
Carcinoma, Ductal, Breast / pathology
Carcinoma, Ductal, Breast / therapy
Carcinoma, Lobular / metabolism*
Carcinoma, Lobular / pathology
Carcinoma, Lobular / therapy
Female
Humans
Immunohistochemistry
In Situ Hybridization
Middle Aged
Neoplasm Staging
Precision Medicine
Quality Assurance, Health Care
Receptor, ErbB-2 / metabolism*
Tissue Array Analysis

Substances

Biomarkers, Tumor
ERBB2 protein, human
Receptor, ErbB-2