Membrane expression of TRAIL receptors DR4, DR5, DcR1 and DcR2 in the normal endometrium, atypical endometrial hyperplasia and endometrioid adenocarcinoma: a tissue microarray study

PURPOSE: To evaluate the membrane expression of DR4, DR5, DcR1 and DcR2 in the normal endometrium (NE), atypical endometrial hyperplasia (AEH) and endometrioid adenocarcinoma (EAC). METHODS: The study comprised 197 patients: 20 NE, 18 AEH and 159 EAC. Tissue microarrays were constructed. Membrane expression of DR4, DR5, DcR1 and DcR2 was examined and presented as total score (TS). RESULTS: In EAC, the membrane expression of DR4, DR5 and DcR2 was less common compared to NE (p < 0.001; p < 0.001; p = 0.018) and AEH (p < 0.001; p < 0.001; p = 0.004). In EAC the membrane expression of DcR1 did not differ when compared to NE (p = 0.055) and AEH (p = 0.173). A strong correlation was found between the type of endometrial tissue (NE/AEH/EAC) and the TS of DR4 (p < 0.001), DR5 (p < 0.001), DcR1 (p = 0.033) and DcR2 (p < 0.001). In EAC, the TS of DR4, DR5, DcR1 and DcR2 was not related to grading and staging. In EAC, the membrane expression of DR5, but not DR4, DcR1 and DcR2, was related to better disease-free survival (DFS). The overall survival (OS) was not related to membrane TRAIL receptors expression. CONCLUSIONS: The membrane expression of the receptors for TRAIL DR4, DR5, DcR1 and DcR2 is greater in NE than EAC. The level of membrane staining of the receptors in EAC is not dependent on grading and staging. In EAC patients, membrane expression of DR4, DR5, DcR1 and DcR2 are not independent predictors of survival.