Biological Distribution of Oncofetal Antigen‐I (OFA‐I) in Gynecologic Tumors and Trophoblastic Tissues

Oncofetal Antigen-I (OFA-I) is a membrane antigen of human cancer cells that cross-reacts with human fetal brain tissues. The presence of this antigen was examined in a variety of histological types of gynecologic tumors, trophoblasts and normal tissues. A total of 22 tumors, 13 trophoblasts and 48 normal tissues were tested by IA absorption using patient's sera containing functionally mono-specific anti-OFA-I. Ovarian carcinoma had the highest percentage of reactivity to OFA-I (78%) followed by cervical carcinoma (40%). Conversely, this antigen was not detected in endometrial carcinoma (0%), normal trophoblast tissue (0%) or hydatidiform mole (0%) or in normal tissues from non-cancer patients. These studies show that OFA-I is frequently detected in ovarian carcinomas.