Monoclonal antibody B72.3 reactivity with human endometrium: a study of normal and malignant tissues

Monoclonal antibody (MAb) B72.3, reactive with a high molecular weight mucin-like glycoprotein [termed tumor-associated glycoprotein (TAG)-72], has been shown previously to react preferentially with adenocarcinomas of the ovary, breast, and colon versus a variety of normal human tissues using immunohistochemical and radioimmunoassay (RIA) techniques. We report here B72.3 reactivity with normal postovulatory endometria, in contrast to proliferative phase epithelia that were nonreactive. Both immunohistochemical and RIA techniques were used to evaluate this phenomenon. TAG-72 expression was also detected in 100% of endometrial adenocarcinomas (n = 32) examined. No MAb B72.3 reactivity was noted in resting, postmenopausal endometria; however, it was present in hyperplastic lesions and appeared to correlate with the severity of histologic abnormality. The utility of MAb B72.3 for screening, radiolocalization, or perhaps therapy of endometrial adenocarcinoma is also discussed.