Prognostic value of immunohistochemically identified CEA, SC, AFP, and S‐100 protein‐positive cells in gastric carcinoma

Gastric tissues from 85 patients with advanced carcinoma were studied immunohistochemically for localization of carcinoembryonic antigen (CEA), secretory component (SC) and alpha‐fetoprotein (AFP), and for S‐100 protein‐positive cells. Our objective was to determine if these factors could serve as prognostic indicators. Forty patients died of recurrence or metastases within 2 years (Group I), and the remaining 45 survived 10 years or longer (Group II) after resection. CEA‐positive cells were present in 93% and 89% of Groups I and II, respectively. In case of staining for CEA, positive results were seen not only in the malignant cells but also in the stroma in 35% of Group I but none in Group II. The immunohistochemical status of SC was not essentially different between Groups I and II; the positive staining was recognized in 50% and in 57%, respectively. Gastric carcinomas rarely reacted to AFP. S‐100 protein‐positive cells, which play an important role in local immunity, were often present in Group II (47%) but rarely in Group I (10%). Thus, in addition to the various prognostic factors available to the surgical pathologist, the presence of CEA and the appearance of S‐100 protein‐positive cells in tumor tissue will aid in predicting the prognosis of patients with advanced gastric carcinoma.