Evidence map›Paper›PMID 42562391›Full record

ArticleCancer reports (Hoboken, N.J.)2026

Human Epidermal Growth Factor Receptor 2-Positive, Claudin-18 Isoform 2-Positive, Mismatch Repair-Deficient Gastric Cancer Revealed by Immunohistochemical Analysis of Surgical Specimens: A Case Report.

Daichi Takagi, Mikito Mori, Kiyohiko Shuto, Chihiro Kosugi, Akihiro Usui, Ryosuke Takayanagi, Shunsuke Sato, Sumiyo Adachi, Takashi Fujino, Kazuto Yamazaki and 1 more

Abstract readCase Reports
In one paragraph

Article in Cancer reports (Hoboken, N.J.), 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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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

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

11 authors.

Daichi TakagiDepartment of Surgery, Teikyo University Chiba Medical Center, Ichihara, Chiba, Japan.
Mikito MoriDepartment of Surgery, Teikyo University Chiba Medical Center, Ichihara, Chiba, Japan.ORCID 0000-0001-8946-3471
Kiyohiko ShutoDepartment of Surgery, Teikyo University Chiba Medical Center, Ichihara, Chiba, Japan.ORCID 0000-0001-7265-8117
Chihiro KosugiDepartment of Surgery, Teikyo University Chiba Medical Center, Ichihara, Chiba, Japan.ORCID 0000-0003-3719-6425
Akihiro UsuiDepartment of Surgery, Teikyo University Chiba Medical Center, Ichihara, Chiba, Japan.
Ryosuke TakayanagiDepartment of Surgery, Teikyo University Chiba Medical Center, Ichihara, Chiba, Japan.
Shunsuke SatoDepartment of Surgery, Teikyo University Chiba Medical Center, Ichihara, Chiba, Japan.
Sumiyo AdachiDepartment of Pathology, Teikyo University Chiba Medical Center, Ichihara, Chiba, Japan.
Takashi FujinoDepartment of Pathology, Teikyo University Chiba Medical Center, Ichihara, Chiba, Japan.
Kazuto YamazakiDepartment of Pathology, Teikyo University Chiba Medical Center, Ichihara, Chiba, Japan.ORCID 0000-0001-8384-5364
Hiroaki ShimizuDepartment of Surgery, Teikyo University Chiba Medical Center, Ichihara, Chiba, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundHuman epidermal growth factor receptor 2 (HER2), mismatch repair (MMR) proteins, claudin-18 isoform 2 (CLDN18.2), and the programmed cell death ligand-1 combined positive score (PD-L1 CPS) are predictive biomarkers for the efficacy of combination chemotherapy in patients with locally advanced unresectable or metastatic gastric or gastroesophageal junction cancer. However, only a small proportion of these patients are positive for at least two of these predictive biomarkers. CASE: We present a rare case of HER2-positive, CLDN18.2-positive, MMR-deficient gastric cancer. A 72-year-old man was initially diagnosed with clinical stage IVB gastric cancer (cT4aN0, M1 PUL). Immunohistochemical analysis of endoscopic biopsy specimens revealed HER2-negative, CLDN18.2-negative, and MMR-proficient gastric cancer. He underwent surgery to remove the hemorrhagic gastric cancer before chemotherapy, and immunohistochemical analysis of surgical specimens revealed HER2-positive, CLDN18.2-positive, and MMR-deficient gastric cancer. Moreover, a transbronchial lung biopsy after surgery showed that one of the bilateral multiple lung nodules was lung adenocarcinoma, and he was ultimately diagnosed with pathological stage IIB gastric cancer and clinical stage IVB lung cancer. He died of lung cancer without any signs of gastric cancer recurrence during 17 months of follow-up.

conclusionHER2-positive, CLDN18.2-positive, MMR-deficient gastric cancer is extremely rare. Adequate endoscopic biopsy sampling from different areas of a tumor is essential for accurate predictive biomarker assessment in patients with gastric or gastroesophageal junction cancer because of intratumoral heterogeneity.

Indexed as

Biomarkers, TumorClaudinsDNA Mismatch RepairErb-b2 Receptor Tyrosine KinasesStomach NeoplasmsAgedGastrectomyHumansImmunohistochemistryLung NeoplasmsMaleBiomarkers, TumorClaudinsCLDN18 protein, humanERBB2 protein, humanErb-b2 Receptor Tyrosine Kinasesclaudin‐18 isoform 2gastric cancerhuman epidermal growth factor receptor 2intratumoral heterogeneitymismatch repair deficiencyprogrammed cell death ligand‐1 combined positive score

Identifiers

PMID42562391
PMCPMC13447005

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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.