Serum concentration of CD44 variant 6 and its relation to prognosis in patients with gastric carcinoma

Abstract

The expression of variant isoforms of CD44 is correlated with the ability of tumor cells to metastasize in some clinical carcinomas. In this study, the serum concentration of soluble splice isoforms of CD44 that shared exon variant 6 (sCD44v6) were measured and the histologic expression of CD44v6 in tumors from patients with gastric carcinoma examined. Serum samples were obtained from 102 patients with primary gastric carcinoma before surgery and serum levels of sCD44v6 were determined with an enzyme-linked immunoadsorbent assay. The expression of CD44v6 in tumors was examined by immunohistochemical staining. Both the serum concentration of sCD44v6 and its expression in tumors were associated significantly with the depth of invasion of the tumor, lymph node metastasis, and clinical stage in patients with diffuse type gastric carcinoma. Among patients with gastric carcinoma, the serum level of sCD44v6 was higher in those with CD44v6 positive tumor cells than in those with CD44v6 negative tumor cells. The serum level of sCD44v6 was a prognostic indicator in patients with diffuse type gastric carcinoma, as was the histologic expression of CD44v6. However, neither CD44v6 nor sCD44v6 was a predictor of survival time in patients with intestinal type gastric carcinoma. It appears that CD44v6 and sCD44v6 are related to the progression of diffuse type gastric carcinoma. An elevated serum level of sCD44v6 may be useful as a prognostic indicator in patients with diffuse type gastric carcinoma.