The positive relationship between the expression of CD44 variant 6 and prognosis in colorectal cancer.

CD44 variant 6 (CD44 v6) is well known as a useful marker of tumor progression; however, its relationship to prognosis has not yet been elucidated. In this study, we investigated the expression of CD44 v6 in colorectal cancer to analyze its relationship to hepatic metastasis as well as to prognosis. Tumor tissues were obtained from 42 patients with colorectal cancer who underwent curative resection with follow-up periods ranging from 5.9 to 71.3 months. There were 21 patients (50%) whose tumors were positive for CD44 v6, with no significant difference between colon and rectal cancer. CD44 v6 staining was significantly related to Dukes' classification as well as to hepatic metastasis. The 5-year survival rate was significantly higher in patients with CD44 v6 negative cancer (84%) than in those with CD44 v6 positive cancer (31%). Thus, we concluded that CD44 v6 could be a reliable prognostic indicator, as well as a predictor of metastatic potential after curative surgery for colorectal cancer.