5T4 ONCOFETAL ANTIGEN EXPRESSION IN OVARIAN-CARCINOMA

5T4 oncofetal antigen is defined by a monoclonal antibody raised again st human placental trophoblast, and recognizes a 72 kD glycoprotein ex pressed in many different carcinomas but detected only at low levels i n some normal epithelia. Analysis of the patterns of expression of 5T4 oncofetal antigen in colorectal carcinomas has indicated a significan t association between the presence of the antigen in tumor cells and m etastatic spread. The 5T4 antigen expression of 72 epithelial ovarian carcinomas has been investigated by immunohistochemistry; 71% of the c arcinomas demonstrated positive 5T4 immunoreactivity in adenocarcinoma cells and/or associated stromal tissue. In order to assess any relati onship to prognosis, the 5T4 phenotypes were analyzed with respect to various clinicopathologic features of the tumors and the clinical outc ome of the patients assessed by survival and disease-free interval. Th ere was a significant correlation between 5T4 expression and more adva nced stage of disease (FIGO stages III and IV) (P < 0.001) and with po orly differentiated tumors (P = 0.036) compared to well or moderately differentiated tumors. patients with tumors expressing 5T4 were less l ikely to respond well to adjuvant therapy (P = 0.030) and had a signif icantly worse outlook in terms of survival (P = 0.033) and disease-fre e interval (P = 0.033). This significance was not demonstrated as acti ng independently of FIGO stage and tumor differentiation.