Evidence map›Paper›PMID 40866784›Full record

ArticleBreast cancer (Tokyo, Japan)2025

Risk of endometrial cancer among breast cancer survivors in Japan: a matched cohort study.

Chitose Kawamura, Krishnan Bhaskaran, Takaaki Konishi, Yasuaki Sagara, Hiroko Bando, Tomohiro Shinozaki, Shuko Nojiri, Motohiko Adomi, Angel Y S Wong, Nanako Tamiya and 1 more

Abstract read
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In one paragraph

Article in Breast cancer (Tokyo, Japan), 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing 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

2 citing papers in PubMed.

  1. Article
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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.

Chitose KawamuraDepartment of Health Services Research, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan.
Krishnan BhaskaranDepartment of Non-Communicable Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.
Takaaki KonishiDepartment of Breast and Endocrine Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Yasuaki SagaraDepartment of Breast Surgical Oncology, Sagara Hospital, Social Medical Corporation Hakuaikai, Kagoshima, Japan.
Hiroko BandoDepartment of Breast and Endocrine Surgery, Institute of Medicine, University of Tsukuba, Ibaraki, Japan.
Tomohiro ShinozakiInterfaculty Initiative in Information Studies, the University of Tokyo, Tokyo, Japan.
Shuko NojiriClinical Translational Science, Juntendo University School of Medicine Graduate School of Medicine, Tokyo, Japan.
Motohiko AdomiDepartment of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
Angel Y S WongDepartment of Non-Communicable Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.
Nanako TamiyaDepartment of Health Services Research, Institute of Medicine, University of Tsukuba, Ibaraki, Japan.
Masao IwagamiDepartment of Digital Health, Institute of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, Japan. iwagami@md.tsukuba.ac.jp.ORCID http://orcid.org/0000-0001-7079-0640

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundBreast cancer (BC) survivors may have an increased risk of endometrial cancer due to shared risk factors and tamoxifen use. However, the risk among women in Japan and that for each endocrine therapy regimen remains unknown when comparing BC survivors to women without BC.

methodsWe conducted a matched-cohort study using the JMDC claims database, covering company employees and their family members in Japan. Between January 2005 and December 2019, women aged 18-74 years with BC were matched to women without BC in a 1:4 ratio by age and database entry timing. Endometrial cancer risk was compared using stratified Cox regression. In addition, starting the follow-up at one year after matching, we assessed risk by endocrine treatment (tamoxifen, aromatase inhibitor [AI], and no endocrine therapy) using unstratified Cox regression.

resultsAmong 23,729 BC survivors and 95,659 matched women (median age, 49.5 years), there were 56 vs 40 endometrial cancer cases (0.73 vs 0.13 cases/1,000 person-years, respectively), with adjusted hazard ratios of 7.71 (95% confidence interval 4.56-13.0). In the analysis by endocrine treatment, tamoxifen (n = 9,183; median 46.3 years), AI (n = 4,582; 58.1 years), and no endocrine therapy (n = 5,763; 49.4 years) cases were 26, 5, and 10 (0.92, 0.43, and 0.61 cases/1,000 person-years, respectively), and the adjusted hazard ratios were 5.67 (3.20-10.0), 2.17 (0.79-5.95), and 3.56 (1.66-7.65), respectively, compared to women without BC.

conclusionsBC survivors in Japan had an increased risk of endometrial cancer compared to women without BC. The risk was higher in women prescribed tamoxifen and those with no endocrine therapy.

Indexed as

Breast NeoplasmsCancer SurvivorsEndometrial NeoplasmsAdolescentAdultAgedAntineoplastic Agents, HormonalAromatase InhibitorsCase-Control StudiesCohort StudiesFemaleFollow-Up StudiesHumansIncidenceJapanMiddle AgedAntineoplastic Agents, HormonalAromatase InhibitorsTamoxifenAromatase inhibitorBreast cancerCancer survivorEndometrial cancerTamoxifen

Identifiers

PMID40866784

What Socratic holds

Textmetadata
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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 Socratic graph.