A putatively new antigen (CSAp) associated with gastrointestinal and ovarian neoplasia.

CSAp is an antigen originally identified in the GW-39 human colonic carcinoma xenograft, and also found in gastric and colonic cancers, fetal colon, normal and inflammatory adult colon, and in some ovarian tumors. However, it appears to be increased primarily in inflammatory, benign , malignant, and fetal human intestine, gastric cancer, and ovarian tumors, as determined by an hemagglutination-inhibition assay. Gel immunodiffusion patterns show that CSAp is immunologically distinct from CEA, NCA, AFP, BOFA, and human liver ferritin. CSAp thus appears to be a putatively new fetal substance with a high degree of specificity for gastric, colonic, and ovarian tissues.