Immunohistochemical Profiles of Endometrioid Endometrial Carcinomas With and Without Metastatic Disease

A minority of endometrial carcinomas present at an advanced stage with a poor prognosis, and should be identified to individualize treatment. Immunohistochemical markers have been studied, but most have not been directly linked to metastasis. This study analyzes the immunohistochemical profile of endometrioid endometrial carcinomas (EECs) with and without metastases, and corresponding metastases. Tissue microarray slides from stage I EECs, stage III-IV EECs, and corresponding metastases were stained and scored for expression of β-catenin, E-cadherin, ER, PR, PTEN, p16, MLH1, PMS2, L1CAM, p53, p21, and MIB1. Scores were compared between primary stage I and III-IV EECs, stage III-IV EECs, and the corresponding metastases, and between intra-abdominal and distant metastases. Primary tumors with distant metastases had a significantly lower ER expression than those without metastases or with intra-abdominal metastases. Distant metastases had a significantly lower PR expression than the corresponding primary tumor and intra-abdominal metastases. In contrast, p16 and PTEN expression was significantly higher in intra-abdominal metastases compared with corresponding primary tumors. Immunohistochemistry predicts both presence and location of EEC metastases. Loss of ER and PR was related to distant spread, and increased expression of PTEN and p16 was related to intra-abdominal spread. Additional research should assess the use of these markers in the diagnostic workup as well as the possibility to target metastases through these markers.