[Expression of trefoil group antigen pS2 in human gastric cancer]

Expression of trefoil group antigen pS2 was examined immunohistochemically in resected stomachs from 121 patients with gastric cancer. Gastric cancer was classified as either undifferentiated or differentiated by histology, and was also divided into gastric type or non-gastric type by mucin-histochemistry. Immunoreactive pS2 was present in 20% of early cancers and 30% of advanced cancers (NS), and in 25% of undifferentiated and 15% of differentiated early cancers (NS), whereas the antigen was present in 38% of undifferentiated and 15% of differentiated advanced cancers (p = 0.04). Positivity for pS2 was found more often in gastric type early cancer (p = 0.04) as well as advanced cancer (p = 0.0002), and was also more frequent in cancers showing scirrhous (p = 0.04) and infiltrative growth (p = 0.03). Cancer positive for pS2 was characterized by mucin-histochemistry and microscopy as gastric type with scirrhous growth and diffuse infiltration, and thus the expression of pS2 in gastric cancer appears to be related to the growth of cancer with these characteristics.