Practical application of non-contact alternating current electric field mixing for reagent-saving in situ hybridisation of HER2.

Abstract

AIMS:

Human epidermal growth factor receptor 2 (HER2)-targeted agents are effective against HER2-positive breast cancers. However, their lack of survival benefit in HER2-negative patients as well as their toxic effects and high cost highlight the need for accurate assessment of HER2 status. Our aim was to evaluate the clinical utility of a reagent-saving in situ hybridisation (Saving ISH) that facilitates hybridisation and saves HER2/chromosome enumeration probe by taking advantage of the non-contact mixing effect of an alternating current (AC) electric field.

METHODS:

With a new device, we apply a high-voltage, low-frequency AC electric field to the tissue sections, which mixes the probe within microdroplets as the voltage is switched on and off. Specimens (n=113) from patients with breast cancers identified immunohistochemically as HER2 0/1(+), (2+) or (3+) were used. The specimens were all tested using conventional dual ISH (DISH), DISH with an automated slide stainer (ASS) and Saving ISH (1:1-1:3 dilution).

RESULTS:

The Saving ISH with 1:2 probe dilution produced stable results with less non-specific staining while using smaller amounts of probe. The accuracy of HER2 status with Saving ISH was equal to standard. We found 96.4% agreement between DISH using ASS and Saving ISH (kappa coefficient=0.912).

CONCLUSIONS:

These results suggest reagent-saving HER2 ISH could be used as a clinical tool for accurate and stable HER2 assessment, even when reagent concentrations vary.

• Authors: Nobuyasu Kurihara, Kazuhiro Imai, Hiroshi Nanjo, Ryuta Nakamura, Yuki Wakamatsu, Koji Akagami, Kaori Terata, Akiyuki Wakita, Yusuke Sato, Satoru Motoyama, Yoichi Akagami, Yoshihiro Minamiya
• Journal: Journal of clinical pathology (J Clin Pathol) Vol. 72 Issue 9 Pg. 603-608 (Sep 2019) ISSN: 1472-4146 [Electronic] England
• PMID: 31129615 (Publication Type: Journal Article)
• Copyright: © Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.

Chemical References

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

Topics

• Biomarkers, Tumor (analysis, genetics)
• Breast Neoplasms (enzymology, genetics, pathology)
• Electricity
• Equipment Design
• Female
• Gene Amplification
• Humans
• Immunohistochemistry
• In Situ Hybridization (instrumentation, methods)
• Predictive Value of Tests
• Receptor, ErbB-2 (analysis, genetics)
• Reproducibility of Results