Luminal A versus luminal B breast cancer: MammaTyper mRNA versus immunohistochemical subtyping with an emphasis on standardised Ki67 labelling‐based or mitotic activity index‐based proliferation assessment

Autor:	Paul J. van Diest, Cornelia M Focke, K. Finsterbusch, Thomas Decker
Rok vydání:	2020
Předmět:	Adult 0301 basic medicine Oncology medicine.medical_specialty Histology Breast Neoplasms Pathology and Forensic Medicine 03 medical and health sciences 0302 clinical medicine Breast cancer Labelling Internal medicine Biomarkers Tumor Mitotic Index medicine Humans RNA Messenger Aged Cell Proliferation Aged 80 and over Messenger RNA Luminal B Breast Cancer business.industry General Medicine Luminal a Middle Aged medicine.disease Immunohistochemistry Mitotic activity index Subtyping Ki-67 Antigen 030104 developmental biology 030220 oncology & carcinogenesis Female business
Zdroj:	Histopathology. 76:650-660
ISSN:	1365-2559 0309-0167
Popis:	Aims Proliferation assessment by the use of Ki67 is a crucial component in intrinsic subtyping of luminal breast cancers (BCs), but suffers from variability between laboratories, observers, and methods. MammaTyper is a quantitative molecular tool that measures mRNA levels of ERBB2, ESR1, PGR and MKI67 in BC, and interprets the results according to the St Gallen 2013 consensus recommendations. We compared MammaTyper with immunohistochemistry (IHC)-based subtypes, with a focus on standardised proliferation assessment. Methods and results We analysed the agreement in assigning subtypes between MammaTyper and receptor IHC in 101 unifocal luminal HER2-negative early BCs of no special type. Two Ki67 counting protocols, Ki67-Global (Ki67-G) and Ki67-HotSpot (Ki67-H), recommended by the International Ki67 in BC Working Group, and the mitotic activity index (MAI) were used for proliferation assessment. The proportions of BCs identified as luminal A and as luminal B were 55% and 45% for MammaTyper, 55% and 45% for IHC + Ki67-G, 36% and 64% for IHC + Ki67-H, and 56% and 44% for IHC + MAI. The levels of agreement between MammaTyper-based and IHC-based subtyping were 84% (κ = 0.679) for IHC + Ki67-G, 72% (κ = 0.462) for IHC + Ki67-H, and 89% (κ = 0.779) for IHC + MAI. Conclusions High rates of agreement between mRNA-based and IHC-based intrinsic subtyping of luminal HER2-negative BC can be achieved. However, the agreement between IHC-based and MammaTyper-based luminal subtypes depends on the proliferation assessment method, and was highest when the MAI was used. Further comparative clinical studies are needed to determine which method is to be preferred, including analysis of cost-effectiveness.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::92c1a099face3c80afc1a5b73c488886 https://doi.org/10.1111/his.14048 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
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