A thermostable antigen associated with ovarian cancer.

Ovarian carcinoma contains an antigen (TA) which is stable at 100 degrees. Rabbit antisera to glycoprotein-rich extracts of tumors detect TA in 70 per cent of ovarian malignancies, in some benign ovarian cysts, certain normal lung preparations, normal cervix, and squamous-cell carcinoma of the cervix. Highest levels may be associated with mucin secretion. No detectible antigen was present in normal ovary, plasma, A, B, and O erythrocytes, leukocytes, placenta, brain, heart, liver, corpus uteri, spleen, skeletal muscle, or kidney. Prolonged digestion of boiled tumor extracts with papain, trypsin, chymotrypsin, on Sephadex G-150 corresponding to a globular protein of 27,000 to 36,000 molecular weight. A beta-globulin mobility is seen in immunoelectrophoresis. It appears that TA differs in tissue specificity and molecular size from other known ovarian cancer associated antigens.