Expression of Tumor‐Associated Antigens on Gastric Biopsy Materials

Abstract

Abstract: We investigated the expressions of SLX, ST‐439 and PLAP, which are regarded as having high specificity for cancer, in borderline lesions of the stomach to ascertain the significance of these potential markers in distinguishing between benign and malignant lesions. SLX, ST‐439 and PLAP expressions in gastric biopsy specimens, from 73 patients with gastric lesions, were visualized using avidin‐biotin‐peroxidase. Although the prevalence of SLX in Group V was 90%. it was also high in intestinal metaplasia (40%) and adenoma (75%). The prevalences of ST‐439 in intestinal metaplasia and adenoma grades l and 2 were 5, 23, and 17%. respectively. On the other hand, the prevalence of ST‐439 was about 60% in adenoma grade 3 and in Groups IV and V. The prevalence and immunostaining range of ST‐439 increased concomitantly with increasing grades of cytological and architectural atypia. The prevalence of PLAP in gastric biopsy materials was 30% overall, but was higher among the differentiated types. Moreover, PLAP was highly specific for cancer because of the negative immunostaining observed in benign lesions such as intestinal metaplasia and adenoma. These results suggest the following: 1) SLX is relatively non‐specific for cancer and thus not useful in the pathological diagnosis of gastric lesions, and 2) borderline lesions with positive ST‐439 mandate careful follow‐up. Moreover, lesions with apparently extensive and intense ST‐439 immunostaining may be gastric cancer and require urgent attention. Furthermore, 3) PLAP may provide additional diagnostic information useful for distinguishing between well‐differentiated adenocarcinoma and borderline lesions including adenoma.