Adenomyosis is not an independent prognostic factor in endometrioid-type endometrial cancer

Background The prognostic significance of adenomyosis in endometrial cancer (EC) remains controversial. Although several studies have suggested an association between adenomyosis and favorable tumor characteristics or improved survival outcomes, it remains unclear whether this relationship persists after adjustment for established clinicopathologic prognostic factors. Aim To investigate the impact of coexisting adenomyosis on clinicopathologic characteristics and survival outcomes in patients with endometrioid-type endometrial cancer.

This retrospective cohort study included 527 consecutive patients with histologically confirmed endometrioid-type endometrial cancer who underwent primary surgical treatment between January 2010 and May 2025 at a tertiary gynecologic oncology center. Patients were categorized according to the presence or absence of adenomyosis identified in hysterectomy specimens. Clinicopathologic characteristics were compared between groups. Disease-free survival (DFS) and overall survival (OS) were evaluated using the Kaplan–Meier method and Cox proportional hazards regression analyses.

Adenomyosis was identified in 154 patients (29.2%). No significant differences were observed between patients with and without adenomyosis regarding age, tumor grade, FIGO stage, myometrial invasion, lymphovascular space invasion (LVSI), lymph node metastasis, or adjuvant treatment (all p > 0.05). Kaplan–Meier analysis demonstrated no significant differences in either DFS or OS according to adenomyosis status (log-rank p = 0.626 and p = 0.697, respectively). In multivariable analysis, LVSI remained the only independent predictor of poorer DFS (HR 2.15, 95% CI 1.02–4.53, p = 0.044), whereas older age (HR 1.08, 95% CI 1.06–1.12, p < 0.001), grade 3 histology (HR 2.11, 95% CI 1.26–3.54, p = 0.005), advanced FIGO stage (HR 1.92, 95% CI 1.18–2.93, p = 0.003), and positive peritoneal cytology (HR 4.47, 95% CI 1.20–16.64, p = 0.026) were independently associated with poorer OS. Adenomyosis was not identified as an independent prognostic factor for either DFS or OS.

In this cohort of patients with endometrioid-type endometrial cancer, coexisting adenomyosis was not independently associated with distinct clinicopathologic features, disease-free survival, or overall survival. Established clinicopathologic factors remained the primary determinants of oncologic outcomes. Similar content being viewed by others Data availability In view of the confidentiality and privacy of the participants, the datasets and supporting materials are available from the corresponding author upon reasonable request.

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Eur J Gynaecol Oncol 45(2):118–126. https://doi.org/10.22514/ejgo.2023.112 Funding None. Author information Authors and Affiliations Contributions Yakup Yalcin: Conceptualization; methodology, data collection, writing original draft, review & editing. Kemal Ozerkan: Conceptualization; methodology, data collection. All authors meet the criteria for authorship, have approved the final article and that all those entitled to authorship are listed as authors. Corresponding author Ethics declarations Ethical compliance All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the Helsinki Declaration and its later amendments or comparable ethical standards. This study was approved by the Bursa Uludağ University Clinical Research Ethics Committee (Protocol No. 2026/157/6 − 5). Due to the retrospective nature of the study, the ethics committee exempted the requirement for informed consent. Conflict of interest The authors declare no potential conflicts of interest with respect to the research, authorship, or publication of this article. Additional information Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Rights and permissions Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law. About this article Cite this article Yalcin, Y., Ozerkan, K. Adenomyosis is not an independent prognostic factor in endometrioid-type endometrial cancer. Ir J Med Sci (2026). https://doi.org/10.1007/s11845-026-04535-4 Received: Accepted: Published: Version of record: DOI: https://doi.org/10.1007/s11845-026-04535-4