Tissue polypeptide antigen - a new tumour marker?

Abstract

The possibility of using Tissue Polypeptide Antigen (TPA) as a tumour marker in the diagnosis and follow‐up of patients with malignant tumours was reported. We have taken up these suggestions and examined the possible role of TPA as a tumour marker in gastric and colo‐rectal carcinoma. TPA and CEA (Carcinoembryonic Antigen) values were determined in 39 patients with gastric and 60 patients with colo‐rectal carcinoma. The tumours were histologically proven. The histological classification of the gastric carcinomas was carried out according to the recommendations of the AJC (American Joint Committee for cancer staging and end results reporting) and that of the colo‐rectal carcinomas was according to Dukes. Fifty‐two surgical patients with benign diseases were used as controls. In this group the incidence of false positive values was 15.3% for TPA and 23% for CEA. In gastric carcinoma 30 out of 39 patients (76.9%) had an elevated TPA level (medium 275.4 n/l), in contrast CEA was elevated in 18 out of 35 patients (46.1%, medium 24.6 ng/ml). In colo‐rectal cancer the TPA level was increased in 61.6% i.e. 37 out of 60 patients (medium 260.2 n/l). Elevated CEA levels were detected in 38 out of 60 patients (63.6%, medium 192 ng/ml). The mean values of TPA and CEA rise with advancing tumour stages. Elevated TPA levels were also found in non malignant diseases. Possible sources of error are inflammatory reactions. Therefore Increased TPA values should be considered indicative of neoplasia only if infections or inflammatory diseases can be excluded and the first value is confirmed by repeated examination. The high incidence of increased values in early tumour stages (Dukes A or AJC 1), seems to justify the inclusion of tests for these antigens into the diagnostic and follow‐up routine of gastric and colo‐rectal} cancer.