5T4 ONCOFETAL ANTIGEN IN GASTRIC-CARCINOMA AND ITS CLINICAL-SIGNIFICANCE

Objective To evaluate the role of 5T4 antigen in gastric cancer progre ssion and prognosis. Design A prospective study of 5T4 antigen express ion in primary, secondary and recurrent gastric carcinoma, the relatio nship to selected prognostic parameters and the course of disease. Pat ients Eighty six patients operated on for gastric cancer. Tissue One h undred and twenty two gastric tumours were studied, including 86 prima ry carcinomas, 32 coexisting lymph node metastases and four recurrent carcinomas. Methods Immunohistochemistry using 5T4 monoclonal antibody on frozen sections.Results The 5T4 antigen was detected in 41% of pri mary gastric tumours including early gastric cancer, A strong relation ship was found between 5T4 positivity and tumour histology, Thus, 52% of gastric carcinomas of intestinal type expressed 5T4 antigen compare d with 28% of the diffuse type (P = 0.028). Among 16 sets of primary g astric carcinomas and regional lymph node metastases, coordinate 5T4 e xpression was seen in 14 cases; the other two showed acquisition of po sitivity on metastatic tumour cells (carcinomas of diffuse type). 5T4 antigen was detected more frequently in carcinomas with p53 accumulati on compared with those with undetectable p53 levels (P = 0.015). The p resence of 5T4 in cancer cells was correlated with poor short-term pro gnosis (24% vs 49% of 2 year survival for 5T4 positive and negative tu mours respectively, P = 0.024). The effect on survival was evident in the p53 negative group, with patients 5T4 positive showing worse survi val (28% vs 60% in 2 years). Conclusions Our results suggest that the assessment of 5T4 expression in gastric carcinoma can be helpful in id entifying patients with poor short-term prognosis. Eur J Gastroenterol Hepatol 10:479-484 (C) 1998 Lippincott-Raven Publishers.