Combined use of carcinoembryonic antigen and tissue polypeptide antigen in oncologic therapy and surveillance

In the Radiology Clinic of our hospital at present more than 2000 patients have been under surveillance using carcinoembryonic antigen (CEA) and tissue polypeptide antigen (TPA) as markers. The available results have indicated that a combination of both parameters may be applicable in monitoring therapy and in the surveillance thereafter in a variety of cancer sites. It was advantageous to utilize a common index derived from the CEA and TPA serum values after natural logarithmic transformation. Hence, discrimination could be achieved between patients without evidence of disease, and those with progressive disease, eg, in breast cancer with a probability of 95%. The following probabilities were established in 10 other tumor sites: colorectum, 96%; seminoma, 94%; lung, 93%; prostate and bladder, 90%; hypernephroma, 87%; sarcoma, 86%; thyroid, 84%; melanoma, 83%; head and neck, 77%; female genitals, 76%. CEA alone was not applicable in some localized tumors, such as seminoma, melanoma, hypernephroma, and sarcoma. Also, in monitoring patients under chemotherapy, it was established in the follow-up of different cancer sites that TPA was superior to CEA. A concordance with the clinical efficacy of the chemotherapy was found for TPA in 94%, for CEA in 54%, and for both markers in 52%. Thus, as a typical proliferation antigen, TPA appeared to react with a greater sensitivity than CEA on the cytostatic effect of chemotherapy.