Secretory component and immunoglobulin in human gastric carcinoma: an immunohistochemical study.

The occurrence of secretory component (SC), IgA, IgG and IgM within tumor cells was immunohistochemically examined in a total of 101 gastric carcinomas comprising 50 early cancers and 51 advanced cancers. In advanced cancers, the frequency of SC was significantly higher in well-differentiated adenocarcinoma than in poorly differentiated adenocarcinoma. The frequency of IgA did not differ with stage of cancer, but the frequencies of IgG and IgM were significantly higher in advanced cancer than in early cancer. The immunoglobulin-producing plasma cells in the stroma of advanced cancer were chiefly IgG, followed by IgA and IgM producers. The intensity of IgA plasma cell infiltration correlated with presence of IgA in tumor cells. No correlation was noted between serum immunoglobulin value and immunoglobulin in tumor cells. The survival rate indicated a tendency for IgG-containing advanced cancers which were infiltrated with many IgG plasma cells to have a better prognosis.