Presence of an estrogen-regulated protein in endometrial cancer.

The presence of an estrogen-regulated protein of Mr 24,000 (24K) was studied in 43 patients diagnosed as having endometrial adenocarcinoma. using an anti-24K monoclonal antibody, a modified immunoperoxidase system (avidinbiotin complex) was used to detect the presence of 24K in formalin-fixed, paraffin-embedded tissue samples. The positivity for 24K was correlated with low tumor histologic grade, few mitotic figures, few nucleoli, and a low degree of nuclear pleomorphism. These data suggest that 24K may be a potential marker of tumor differentiation.