Zhang Xiaobo, Han Bo, Shen Danhua
Department of Pathology, Peking University People's Hospital, Beijing 100044, China.
Cancers (Basel). 2024 Oct 21;16(20):3555. doi: 10.3390/cancers16203555.
: Microcystic, elongated, and fragmented (MELF) invasion is a special invasion pattern in endometrioid endometrial cancer (EEC). This study aimed to investigate the clinical, pathological, and molecular features of the MELF pattern and its prognostic value in patients with EEC. : The clinical and pathological data of 342 patients with EEC were retrospectively collected at Peking University People's Hospital from January 2019 to December 2022. Some key clinicopathological features were evaluated, including the tumor grade, Federation of Gynecology and Obstetrics (FIGO) staging, cervical stromal involvement, lymph node status, and lymphatic vascular space infiltration (LVSI). Immunohistochemical staining and molecular tests were performed, and the relevant literature was reviewed. : The MELF pattern was more prevalent in low-grade EEC. A significant correlation was found between the MELF pattern and advanced FIGO staging, LVSI, the depth of myometrial invasion, cervical stromal involvement, and lymph node metastasis (LNM). The incidence of mismatch-repair-deficient (MMRd) proteins was much higher in the MELF group than in the no-MELF group. Molecular testing revealed that, after copy number-low (CNL), microsatellite instability-high (MSI-H) was the second-most frequent subtype in the MELF group. The recurrence risk did not significantly differ between the MELF and no-MELF groups, but the differences among the four molecular subtypes were statistically significant. However, the MELF group experienced a shorter recurrence time. Among the four molecular subtypes, the recurrence risk was the highest in the CNH subgroup, followed by the MSI-H subgroup. : MELF is a special invasion pattern in EEC and is associated with distinct clinicopathological and molecular characteristics, including the latest 2023 FIGO staging. Further research is warranted to explore its implications for treatment strategies and patient outcomes.
微囊性、细长形及破碎状（MELF）浸润是子宫内膜样腺癌（EEC）中的一种特殊浸润模式。本研究旨在探讨MELF模式在EEC患者中的临床、病理及分子特征及其预后价值。
2019年1月至2022年12月，北京大学人民医院对342例EEC患者的临床和病理资料进行了回顾性收集。评估了一些关键的临床病理特征，包括肿瘤分级、国际妇产科联盟（FIGO）分期、宫颈间质受累情况、淋巴结状态及淋巴血管间隙浸润（LVSI）。进行了免疫组织化学染色和分子检测，并复习了相关文献。
MELF模式在低级别EEC中更为常见。发现MELF模式与FIGO晚期分期、LVSI、肌层浸润深度、宫颈间质受累及淋巴结转移（LNM）之间存在显著相关性。错配修复缺陷（MMRd）蛋白在MELF组中的发生率远高于非MELF组。分子检测显示，在拷贝数低（CNL）之后，微卫星高度不稳定（MSI-H）是MELF组中第二常见的亚型。MELF组和非MELF组的复发风险无显著差异，但四种分子亚型之间的差异具有统计学意义。然而，MELF组的复发时间较短。在四种分子亚型中，CNH亚组的复发风险最高，其次是MSI-H亚组。
MELF是EEC中的一种特殊浸润模式，与独特的临床病理和分子特征相关，包括最新的2023年FIGO分期。有必要进一步研究以探讨其对治疗策略和患者预后的影响。
