Expression of CD44v6 in advanced gastric cancer and its relationship to hematogenous metastasis and long-term prognosis

BACKGROUND AND OBJECTIVES: Variants of CD44 have been proposed to be important in promoting tumor progression and metastasis. We attempted to determine the expression of CD44v6 product in advanced gastric cancer and to evaluate its prognostic value. METHODS: The expression of CD44v6 was analyzed immunohistochemically in advanced gastric cancers using monoclonal antibody, 44-2V. We investigated the relationship between CD44v6 expression and prognosis in 201 gastric cancer patients. RESULTS: Ninety-five (47.3%) of 201 cancer tissues expressed CD44v6. The expression of CD44v6 protein was significantly higher in differentiated, adenocarcinoma than in diffuse type carcinoma. The CD44v6-positive cancers were more frequently associated with hematogenous metastasis. There was no significant correlation between CD44v6 immunoreactivity, and prognosis among the combined cases. Among patients with differentiated adenocarcinoma, however, the prognosis was significantly poorer in patients with CD44v6-positive tumors than in those with CD44v6-negative tumors. CONCLUSIONS: CD44v6 protein may have an important role in hematogenous metastasis, and may be a biologic marker of prognostic significance in differentiated type gastric cancers.