Immunohistochemical expression of the CD44 variant 6 in colorectal adenocarcinoma.

The CD44 variant 6 (CD44 v6) has been postulated to be involved in both carcinogenesis and tumor progression. In the present study, CD44 v6 was stained immunohistochemically in 63 colorectal cancer tissues to assess significance of CD44 v6 in the carcinogenesis and progression of colorectal carcinoma. None of the normal colonocytes showed an expression of CD44 v6. CD44 v6 expression was very strong in 24, moderate in 13, and negative in 26 tumor tissues. A negative or moderate expression of CD44 v6 was significantly associated with a larger tumor size (P < 0.05) and invasion through the bowel wall (P < 0.01). There was no correlation between the expression of CD44 v6 and gross type, histologic differentiation, lymph node involvement, liver metastasis, and clinical stage of the disease. The present study showed that the expression of CD44 v6 was characteristic of neoplastic changes in the colonocytes and that a diminished expression of CD44 v6 was associated with the penetration of colorectal cancer through the bowel wall, but not with either lymph node or distant metastasis.