Evidence map›Paper›PMID 42318191›Full record

ArticleSurgical case reports2026

Spindle Cell (Metaplastic) Carcinoma of the Breast Showing No Clinical Benefit with Pembrolizumab-Based Neoadjuvant Chemoimmunotherapy.

Rin Yamada, Keita Kai, Kaori Hidaka, Daiki Yoshii, Ren Shirotani, Tomoka Takahashi, Yuko Miyasato, Seiichi Murakami, Yoshiki Mikami, Yoshihiro Komohara and 1 more

Abstract readCase Reports
In one paragraph

Article in Surgical case reports, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

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

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

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

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors.

Rin YamadaDepartment of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
Keita KaiDepartment of Diagnostic Pathology, Kumamoto University Hospital, Kumamoto, Kumamoto, Japan.
Kaori HidakaDepartment of Breast and Endocrine Surgery, Kumamoto University Hospital, Kumamoto, Kumamoto, Japan.
Daiki YoshiiDepartment of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
Ren ShirotaniDepartment of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
Tomoka TakahashiDepartment of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
Yuko MiyasatoDepartment of Diagnostic Pathology, Kumamoto University Hospital, Kumamoto, Kumamoto, Japan.
Seiichi MurakamiDepartment of Surgery, Japan Community Healthcare Organization Amakusa Central General Hospital, Amakusa, Kumamoto, Japan.
Yoshiki MikamiDepartment of Diagnostic Pathology, Kumamoto University Hospital, Kumamoto, Kumamoto, Japan.
Yoshihiro KomoharaDepartment of Cell Pathology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Kumamoto, Japan.
Yutaka YamamotoDepartment of Breast and Endocrine Surgery, Kumamoto University Hospital, Kumamoto, Kumamoto, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

introductionMetaplastic carcinoma (MC) of the breast is a rare subtype that is frequently chemoresistant, and clinical evidence for immune checkpoint inhibitor (ICI) therapy remains limited. Here, we report a case of spindle cell carcinoma (SpCC) MC showing primary resistance to neoadjuvant chemo-immunotherapy and describe features associated with the tumor immune microenvironment. CASE PRESENTATION: A woman with a 10-year history of a left breast mass presented with rapid enlargement to approximately 7 cm. Core needle biopsy revealed SpCC that was negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2, with a high Ki-67 labeling index. Imaging suggested ipsilateral axillary nodal involvement, and neoadjuvant pembrolizumab combined with platinum/taxane chemotherapy was initiated. However, after 2 cycles, the tumor further enlarged with ulceration and protrusion from the prior biopsy site, consistent with progressive disease, and the patient underwent total mastectomy with axillary dissection. Histologically, the tumor consisted of high-grade atypical spindle cells with necrosis and minimal treatment effect. Immunohistochemistry demonstrated strong expression of programmed death-ligand 1 in both tumor and immune cells and increased CD8+ T-cell infiltration after therapy. By contrast, tumor cells showed significantly downregulated human leukocyte antigen (HLA)-A/B/C and β2-microglobulin, suggesting impaired antigen presentation. Increased CD163/CD204/triggering receptor expressed on myeloid cells 2-positive tumor-associated macrophages and focal transforming growth factor-β expression were also observed.

conclusionsThese findings suggest that HLA class I downregulation may contribute to ICI resistance.

Indexed as

breasthuman leukocyte antigenimmune checkpoint inhibitormetaplastic carcinomaspindle cell carcinomatumor-associated macrophageβ2-microglobulin

Identifiers

PMID42318191
PMCPMC13273591

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