Decline in Antigenicity of Tumor Markers by Storage Time Using Pathology Sections Cut From Tissue Microarrays.pdf (265.52 kB)
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Decline in Antigenicity of Tumor Markers by Storage Time Using Pathology Sections Cut From Tissue Microarrays.

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journal contribution
posted on 01.08.2019, 10:49 by FM Blows, HR Ali, S-J Dawson, J Le Quesne, E Provenzano, C Caldas, PDP Pharoah
Sectioning a whole tissue microarrray (TMA block) and storing the sections maximizes the number of sections obtained, but may impair the antigenicity of the stored sections. We have investigated the impact of TMA section storage on antigenicity. First, we reexamined existing TMA data to determine whether antigenicity in stored sections changes over time. Component scores for each marker, based on cellular compartment of staining and score-type, were evaluated separately. Residual components scores adjusted for grade, tumor size, and node positivity, were regressed on the number of days storage to evaluate the effect of storage time. Storage time ranged from 2 to 1897 days, and the mean change in antigenicity per year ranged from -0.88 (95% confidence interval, -1.11 to -0.65) to 0.035 (95% confidence interval, 0.016-0.054). Further analysis showed no significant improvement in the fit of survival models if storage time adjusted scores were included in the models rather than unadjusted scores. We then compared 3 ways of processing TMA sections after cutting-immediate staining, staining after 1 year, and staining after 1 year coated in wax-on the immunohistochemistry results for: progesterone receptor, a routinely used, robust antibody, and MKI67, which is generally considered less robust. The progesterone receptor scores for stored sections were similar to those for unstored sections, whereas the MKI67 scores for stored sections were substantially different to those for unstored sections. Wax coating made little difference to the results. Biomarker antigenicity shows a small decline over time that is unlikely to have an important effect on studies of prognostic biomarkers.

Funding

Cancer Research UK (C490/A10119, C490/A10124, and C490/A16561) and funding from the NIHR Biomedical Research Centre.

History

Citation

Applied Immunohistochemistry and Molecular Morphology, 2016, 24 (3), pp. 221-226

Author affiliation

/Organisation/COLLEGE OF LIFE SCIENCES/School of Medicine/Cancer Research Centre

Version

VoR (Version of Record)

Published in

Applied Immunohistochemistry and Molecular Morphology

Publisher

Lippincott, Williams & Wilkins

eissn

1533-4058

Copyright date

2016

Available date

01/08/2019

Language

en

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