The expression of syndecan-1 is related to the risk of endometrial hyperplasia progressing to endometrial carcinoma.

Objective: Aberrant expression of the cell surface proteoglycan, syndecan-1, is found in many malignancies. The current study describes the immunohistochemical study of syndecan-1 expression in normal, hyperplastic, and malignant endometrial tissues for evaluation of application as a parameter of cancer progression in patients with endometrial hyperplasia.

Methods: Immunohistochemical staining of syndecan-1 was performed in 101 formalin fixed, paraffin embedded sections of normal, hyperplastic, and malignant endometrial tissues. We analyzed specimens from patients with normal endometrium (NE, N=10) as controls, and those of simple hyperplasia (SH, N=20), complex hyperplasia without atypia (CH, N=20), atypical hyperplasia (AH, N=20), and endometrial cancer (EC, N=31).

Results: The mean rank of expression scores based on the frequency of syndecan-1 staining were 31.6, 20.5, 52.9, 72.1, and 62.1 for NE, SH, CH, AH and EC, respectively (p<0.001). Syndecan-1 expression was significantly greater in CH (p<0.001) or AH (p<0.001) than in SH, and significantly greater in AH compared to CH (p=0.028). Syndecan-1 is more frequently expressed in CH (p=0.042), AH (p<0.001), or EC (p=0.002) than in NE. Syndecan-1 expression did not differ significantly between NE and SH (p=0.248).

Conclusion: Syndecan-1 expression appears to be useful as a predictive indicator in endometrial hyperplasia.