Evidence map›Paper›PMID 41989526›Full record

Observational studyBreast cancer (Tokyo, Japan)2026

Differences in drug efficacy and prognosis between primary and metastatic sites for de novo stage IV breast cancer: an exploratory analysis of a phase III trial, JCOG1017.

Kiyo Tanaka, Akihiko Shimomura, Makoto Ishitobi, Takashi Yamanaka, Takahiro Tsukioki, Hiroji Iwata, Fumikata Hara, Tomomi Fujisawa, Keita Sasaki, Ryo Sadachi and 12 more

Erratum issuedAbstract readObservational Study
PubMed Full text at PMC Publisher
In one paragraph

Observational study in Breast cancer (Tokyo, Japan), 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. 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

5 · Who and what money

Authors and funding

22 authors.

Kiyo TanakaDepartment of Breast Surgery, Toranomon Hospital, 2-2-2 Toranomon, Minato-ku, Tokyo, 105-8470, Japan.ORCID http://orcid.org/0000-0001-6812-6150
Akihiko ShimomuraDepartment of Breast and Medical Oncology, National Center for Global Health and Medicine, Tokyo, Japan.
Makoto IshitobiDepartment of Breast Surgery, Osaka Habikino Medical Center, Osaka, Japan.
Takashi YamanakaDepartment of Breast Surgery, Kanagawa Cancer Center, Kanagawa, Japan.
Takahiro TsukiokiDepartment of Breast and Endocrine Surgery, Okayama University Hospital, Okayama, Japan.
Hiroji IwataDepartment of Advanced Clinical Research and Development, Nagoya City University Graduate School of Medical Sciences, Nagoya , Aichi, Japan.
Fumikata HaraDepartment of Breast Oncology, Aichi Cancer Center, Nagoya, Japan.
Tomomi FujisawaDepartment of Breast Oncology, Gunma Prefectural Cancer Center, Gunma, Japan.
Keita SasakiClinical Oncology Group Data Center/Operations Office, National Cancer Center Hospital, Tokyo, Japan.
Ryo SadachiClinical Oncology Group Data Center/Operations Office, National Cancer Center Hospital, Tokyo, Japan.
Riku KajikawaClinical Oncology Group Data Center/Operations Office, National Cancer Center Hospital, Tokyo, Japan.
Takehiko SakaiDepartment of Breast Medical Oncology, The Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan.
Yasuaki SagaraDepartment of Breast Surgery, Sagara Hospital, Kagoshima, Japan.
Hideo ShigematsuDepartment of Breast Surgery, Hiroshima University Hospital, Hiroshima, Japan.
Yukinori OzakiDepartment of Breast Medical Oncology, The Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan.
Kazuki NozawaDepartment of Advanced Clinical Research and Development, Nagoya City University Graduate School of Medical Sciences, Nagoya , Aichi, Japan.
Kazuki SudoDepartment of Medical Oncology, National Cancer Center Hospital, Tokyo, Japan.
Yoichi NaitoDepartment of General Internal Medicine, National Cancer Center Hospital East, Chiba, Japan.
Kaori TerataDepartment of Breast and Endocrine Surgery, Akita University Hospital, Akita, Japan.
Toshiyuki IshibaDepartment of Breast Surgery, Institute of Science Tokyo Hospital, Tokyo, Japan.
Haruhiko FukudaClinical Oncology Group Data Center/Operations Office, National Cancer Center Hospital, Tokyo, Japan.
Tadahiko ShienDepartment of Breast and Endocrine Surgery, Okayama University Hospital, Okayama, Japan. tshien@md.okayama-u.ac.jp.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundBreast cancer is a highly heterogeneous disease, with biological factors like estrogen receptor, progesterone receptor, and HER2 receptor differing between primary and metastatic sites, potentially affecting treatment response. This exploratory analysis aims to differentiate drug efficacy and long-term prognosis between these sites in stage IV breast cancer.

methodsPatients from JCOG1017, a phase III trial evaluating the role of primary tumor resection, who received primary systemic therapy (PST) were evaluated at three months. In this analysis, treatment response was assessed separately in primary and metastatic sites. Patients were categorized into four groups: discordant I (primary non-PD, metastatic PD), concordant I (both PD), discordant II (primary PD, metastatic non-PD), and concordant II (both non-PD).

resultsAmong 271 patients, overall discordance proportion of treatment response between primary and metastatic sites was 25.1%. Group distribution was 24.7% (discordant I), 9.6% (concordant I), 0.4% (discordant II), and 65.3% (concordant II). Discordance was more frequent in luminal (28.9%), triple-negative (25.0%), and luminal-HER2 (22.0%) subtypes than in HER2-enriched (11.1%). Survival analysis showed prognostic differences: concordant II, with both sites non-PD, demonstrated the most favorable outcome compared with discordant I (HR 0.556; 95% confidence interval, 0.396–0.782).

conclusionsOne-fourth of patients exhibited discordant responses between primary and metastatic sites in early treatment phases. These discrepancies were associated with survival differences, emphasizing the importance of evaluating both primary and metastatic lesions when assessing efficacy and determining treatment strategies in de novo stage IV breast cancer.

Indexed as

Antineoplastic Combined Chemotherapy ProtocolsBreast NeoplasmsAdultAgedClinical Trials, Phase III as TopicErb-b2 Receptor Tyrosine KinasesFemaleHumansMiddle AgedNeoplasm MetastasisNeoplasm StagingPrognosisRandomized Controlled Trials as TopicReceptors, EstrogenReceptors, ProgesteroneTreatment OutcomeERBB2 protein, humanErb-b2 Receptor Tyrosine KinasesReceptors, EstrogenReceptors, ProgesteroneDe novo stage IV breast cancerDiscordance of treatment response between primary and metastatic sitesOverall survivalPrimary systemic therapy

Identifiers

PMID41989526
PMCPMC13283142

What OpenQuestion holds

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LicenceCC BY-NC-ND
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Registered trials

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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.