Prognostic significance of T antigen expression in patients with gastric carcinoma

Thomsen-Freidenreich (T) antigen, the immediate precursor antigen of the human blood MN system, has been detected in malignant cells, but not in most normal cells in which it is cryptic but can be unmasked by desialylation. In this study, we determined the prognostic significance of T antigen in specimens with gastric carcinoma.

Expression of T antigen was studied immunohistochemically in 157 gastric carcinoma tissue specimens obtained at surgery from the First Department of Surgery, Osaka City University Medical School between 1983 and 1987.

T antigen expression was detected in 72 of the tumors (45.9%). The staining pattern was inclined to change from a luminal surface type to a cytoplasmic type in accordance with decreasing degree of cell differentiation. The rate of expression of T antigen significantly increased (P < 0.05) with serosal invasion, and was significantly higher (P < 0.01) in patients with hepatic or lymph node metastasis or peritoneal dissemination than in those without such metastasis or dissemination. Furthermore, among patients with Stage III or IV disease, those with T antigen-positive tumors had a significantly poorer prognosis than those with T antigen-negative tumors.

Our findings suggest that relationships exist between expression of T antigen and depth of invasion, hepatic metastasis, lymph node metastasis, or peritoneal dissemination, and that T antigen may be a good indicator of the prognosis of patients with gastric carcinoma.