Oncofetal antigen-I: distribution in human tumors.

Oncofetal antigen-I (OFA-I) is a human tumor-associated fetal antigen that cross-reacts with fetal brain. The biological distribution of this antigen was studied in a variety of histologic types of human tumors and normal tissues. A total of 170 human tumors and 89 normal tissues obtained from biopsied and autopsied specimens were tested by immune adherence absorption assay. The antigen was most prevalent in malignant melanomas (82%); next in order of incidence were lung carcinomas (71%), sarcomas (61%), brain tumors (58%), and breast carcinomas (53%). However, OFA-I was found in only 15% of gastrointestinal tumors. The four hepatoma specimens tested were negative for OFA-I. OFA-I was also present in metastases and normal-appearing tissues of patients with OFA-I positive tumors but was not found in normal tissues from noncancer patients. These studies demonstrated that OFA-1 is widely distributed among human tumors. It appears to be more prevalent in tumors of ectodermal and mesodermal origin.