Experimental studies of tumor radioimmunodetection using antibody mixtures against carcinoembryonic antigen (CEA) and colon-specific antigen-p (CSAp).

Experiments with the GW-39 human colonic carcinoma growing in hamsters showed that injection of radioactive antibody to a colorectal-specific, tumor-associated antigen, CSAp, results in better tumor radiolocalization than was seen previously with radioantibodies to carcinoembryonic antigen (CEA). However, a mixture of both radioactive antibodies resulted in potentiation of CEA-tumor radioimmunodetection without affecting CSAp-tumor radiolocalization. Hence, multi-marker antibody mixtures may be the method of choice in cancer radioimmunodetection.