SYSTEMATIC REVIEW article

Front. Oncol.

Sec. Gynecological Oncology

Volume 15 - 2025 | doi: 10.3389/fonc.2025.1527324

Impact of the Microcystic, Elongated, and Fragmented (MELF) Invasion Pattern on prognosis in Endometrial Carcinoma: A Comprehensive Meta-Analysis

Provisionally accepted
Li  ZhouLi ZhouChengyao  LiChengyao LiJianguo  ZhaoJianguo ZhaoPu  LiPu LiPengpeng  QuPengpeng Qu*
  • Tianjin Central Hospital for Gynecology and Obstetrics, Tianjin, China

The final, formatted version of the article will be published soon.

The prognostic significance of the microcystic, elongated, and fragmented (MELF) invasion pattern in endometrial carcinoma (EC) has not been fully elucidated. This study conducted a systematic search across five electronic databases (PubMed, EMBASE, Cochrane, Web of Science, and the Chinese National Knowledge Infrastructure (CNKI)) from inception to April 2025. Assessment focused on overall survival (OS), disease-free survival (DFS), lymph node metastasis (LNM), and recurrence rate (RR) as primary outcomes. Meta-analysis calculations of overall odds ratios (ORs) and hazard ratios (HRs) with corresponding 95% confidence intervals (CIs) elucidated the impact of the MELF pattern on clinical outcomes. Analysis of 18 studies involving 5587 participants revealed a significant correlation between the presence of MELF pattern and heightened LNM incidence (OR 3.52, 95% CI: 2.17–5.71, p < 0.001). Univariate analysis indicated a notable inverse relationship between MELF pattern and OS (HR 2.31, 95% CI: 1.67–3.21, p < 0.001), as well as DFS (HR 1.67, 95% CI: 1.20–2.30, p = 0.002). In multivariate analysis, however, this association did not achieve statistical significance (for OS, HR 1.54, 95% CI: 0.99–2.41, p = 0.056; for DFS, HR 1.25, 95% CI: 0.90–1.74, p = 0.191). The findings of this meta-analysis demonstrated that the MELF pattern was linked to elevated risk of LNM and poorer OS and DFS outcomes. The correlation was influenced by various factors including surgical interventions and adjuvant therapies. While potentially increasing the risk of recurrence, the findings did not demonstrate statistical significance (OR 1.15, 95% CI: 0.61–2.16; p = 0.669).

Keywords: Microcystic, elongated, and fragmented (MELF) pattern, endometrial carcinoma, lymph node metastasis, Molecular classification, prognosis

Received: 13 Nov 2024; Accepted: 03 Jun 2025.

Copyright: © 2025 Zhou, Li, Zhao, Li and Qu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Pengpeng Qu, Tianjin Central Hospital for Gynecology and Obstetrics, Tianjin, China

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.