Immunohistochemical detection of sialosyl-Tn antigen in carcinoma of the prostate

Objective To investigate the expression of sialosyl-Tn antigen (STn) in human benign and malignant prostate. Materials and methods The expression of STn was investigated immunohistochemically in formalin-fixed and paraffin-embedded tissue specimens from 56 patients with primary prostatic adenocarcinoma (median age 74.3 years, range 47-59) and 20 patients with benign prostatic hyperplasia (median age 73.4 gears, range 60-87). Results STn was expressed in only three (4%) of the 20 hyperplastic glands and the benign areas adjacent to the 54 carcinomas; by contrast, STn was expressed in 34 (61%) of the 56 carcinomas, The frequency of STn positivity was much higher in well-differentiated carcinomas than in those poorly differentiated. Conclusion STn is expressed with malignant transformation of the prostatic epithelial cells and immunohistochemical methods using commercially available STn monoclonal antibody may be useful as an adjunct for distinguishing carcinoma from benign tissue.