Immunohistochemical Expression of Carbohydrate Antigen 19–9 in Gastric Carcinoma

Immunohistochemical localization for carbohydrate antigen 19–9 (CA19–9) was studied in the gastric tissues from 115 patients with advanced gastric carcinoma. We compared two groups: 57 patients who died of recurrence or metastases within 2 yr (group I) and 58 patients who survived 5 yr or more after resection (group II). The staining patterns were classified into negative, apical, and/or cytoplasmic type and stromal type. Thirty‐three cases (58%) of group I showed a stromal type, whereas only 17 cases (30%) of group II showed the same type. In undifferentiated type carcinoma, the stromal type was seen in 20 cases (65%) of group I and seven cases (23%) of group II. However, in differentiated type carcinoma, there was only a small difference in the appearance of stromal type between group I (50%) and group II (37%). The immunohistochemical localization for CA19–9 in the tumor tissues, particularly in undifferentiated carcinoma, will be useful in predicting the prognosis of the patients with advanced gastric carcinoma.