Aberrant maspin expression in human endometrial cancer

Maspin, a mammary serine protease inhibitor, was originally reported as a tumor suppressor gene in breast cancer. The purpose of the present study was to examine maspin expression and evaluate its clinicopathological significance in endometrial cancer. We examined maspin expression immunohistochemically in 41 cases with endometrioid adenocarcinoma. DNA methylation status at the maspin promoter region was determined by the methylation‐specific polymerase chain reaction method. Aberrant maspin expression was observed in 27 (66%) of 41 endometrioid adenocarcinomas but not in normal endometrial glands. Maspin immunoreactivity of the tumor cells varied in incidence and density among tumors. Positive staining was correlated significantly with the presence of squamous differentiation (presence vs absence = 11/11 [100%] vs 16/30 [53%], P