Evidence map›Paper›PMID 42329461›Full record

ArticleBreast cancer research and treatment2026

Clinical implications of discordance in HER2 reassessment from HercepTest to 4B5 in metastatic breast cancer.

Yuhei Yamaguchi, Mai Hoshino, Tatsunori Shimoi, Hiroki Tamura, Yutaka Natori, Takuro Saiki, Taro Yamanaka, Rui Kitadai, Ayumi Saito, Shosuke Kita and 9 more

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Article in Breast cancer research and treatment, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

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5 · Who and what money

Authors and funding

19 authors.

Yuhei YamaguchiDepartment of Medical Oncology, National Cancer Center Hospital, Tsukiji 5-1-1, Chuo-ku, Tokyo, 104-0045, Japan.ORCID http://orcid.org/0009-0002-9544-1193
Mai HoshinoDepartment of Medical Oncology, National Cancer Center Hospital, Tsukiji 5-1-1, Chuo-ku, Tokyo, 104-0045, Japan.ORCID http://orcid.org/0009-0008-2232-6315
Tatsunori ShimoiDepartment of Medical Oncology, National Cancer Center Hospital, Tsukiji 5-1-1, Chuo-ku, Tokyo, 104-0045, Japan. tshimoi@ncc.go.jp.ORCID http://orcid.org/0000-0002-3603-8575
Hiroki TamuraDepartment of Medical Oncology, National Cancer Center Hospital, Tsukiji 5-1-1, Chuo-ku, Tokyo, 104-0045, Japan.
Yutaka NatoriDepartment of Medical Oncology, National Cancer Center Hospital, Tsukiji 5-1-1, Chuo-ku, Tokyo, 104-0045, Japan.
Takuro SaikiDepartment of Medical Oncology, National Cancer Center Hospital, Tsukiji 5-1-1, Chuo-ku, Tokyo, 104-0045, Japan.
Taro YamanakaDepartment of Medical Oncology, National Cancer Center Hospital, Tsukiji 5-1-1, Chuo-ku, Tokyo, 104-0045, Japan.ORCID http://orcid.org/0000-0001-9346-5090
Rui KitadaiDepartment of Medical Oncology, National Cancer Center Hospital, Tsukiji 5-1-1, Chuo-ku, Tokyo, 104-0045, Japan.
Ayumi SaitoDepartment of Medical Oncology, National Cancer Center Hospital, Tsukiji 5-1-1, Chuo-ku, Tokyo, 104-0045, Japan.
Shosuke KitaDepartment of Medical Oncology, National Cancer Center Hospital, Tsukiji 5-1-1, Chuo-ku, Tokyo, 104-0045, Japan.
Aiko MaejimaDepartment of Medical Oncology, National Cancer Center Hospital, Tsukiji 5-1-1, Chuo-ku, Tokyo, 104-0045, Japan.
Yuki KojimaDepartment of Medical Oncology, National Cancer Center Hospital, Tsukiji 5-1-1, Chuo-ku, Tokyo, 104-0045, Japan.
Kazuki SudoDepartment of Medical Oncology, National Cancer Center Hospital, Tsukiji 5-1-1, Chuo-ku, Tokyo, 104-0045, Japan.
Akiko Miyagi MaeshimaDepartment of Diagnostic Pathology, National Cancer Center Hospital, Tokyo, Japan.
Takeshi MurataDepartment of Breast Surgery, National Cancer Center Hospital, Tokyo, Japan.
Shin TakayamaDepartment of Breast Surgery, National Cancer Center Hospital, Tokyo, Japan.
Yasuto NaoiDivision of Endocrine & Breast Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Kan YonemoriDepartment of Medical Oncology, National Cancer Center Hospital, Tsukiji 5-1-1, Chuo-ku, Tokyo, 104-0045, Japan.
Masayuki YoshidaDepartment of Diagnostic Pathology, National Cancer Center Hospital, Tokyo, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeHER2-low breast cancer has emerged as a therapeutic category following the DESTINY-Breast04 trial, where trastuzumab deruxtecan (T-DXd) improved survival. As the Ventana 4B5 assay was the companion diagnostic in this trial, many patients previously tested with the Dako HercepTest required reassessment. However, the frequency and clinical predictors of discrepancies between these assays remain unclear. This study aimed to evaluate discordance frequency between HercepTest

methodsWe retrospectively analyzed patients who underwent prior HER2 testing with HercepTest and subsequent reassessment with 4B5 between May 2023 and November 2024 at our institution. The primary endpoint was reassessment discordance, and secondary analyses examined the clinicopathological predictors of discordance.

resultsEighty-four patients (median age: 58 years) were included. Specimens were obtained from primary tumors (28.6%) and metastatic lesions (71.4%); 15.5% were resections and 84.5% were biopsies. The discordance rate between HercepTest

conclusionsDiscordance between HercepTest

Indexed as

Biomarkers, TumorBreast NeoplasmsErb-b2 Receptor Tyrosine KinasesAdultAgedFemaleHumansImmunohistochemistryMiddle AgedNeoplasm MetastasisPrognosisRetrospective StudiesTrastuzumabBiomarkers, TumorERBB2 protein, humanErb-b2 Receptor Tyrosine KinasesTrastuzumab4B5ConcordanceHER2HER2-lowHercepTest

Identifiers

PMID42329461
PMCPMC13287252

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.