Expression of two CD44 variant proteins (v3 and v6 ) in human colorectalcarcinoma and its relevance for prognosis

AIM To evaluate the expression of CD44v3 and v6 protein in colorectal carcinoma and its prognosticsignificance.METHODS One hundred and twenty-one cases of formalin-fixed paraffin-embedded colorectal carcinomaspecimens were retrospectively analyzed using EnvisionTM immunohistochemical method with the monoclonalantibody CD44v3 and v6. The median follow-up time was 67.77 months and the prognostic value of theCD44v3 and CD44v6 was assessed using univariate and multivariate survival analysis.RESULTS The positive rates of CD44v3 and v6 protein were 60.3% and 57.9%, respectively. There wassignificant correlation between CD44v3 immunoreactivity and tumor location, lymph node metastasis, distantmetastasis and Duke's stage (P< 0.05, Spearman correlation test). Significant correlation between CD44v6immunoreactivity and patients' gender, lymph node metastasis, distant metastasis, Duke's stage was alsonoticed (P < 0.05, Spearman correlation test). The 5-year survival rates were 81.25% and 60.27% inCD44v3 negative and positive cases, respectively. As CD44v6, the 5-year survival rates were 80.39% and60.00% in CD44v6 negative and positive cases, respectively; these differences between the two groups ofpatients were significant (P<0.05, Log-rank test). In multivariate analysis using the Cox regression model,CD44v3 expression emerges as an independent prognostic indicator.CONCLUSION CD44v3 and v6 might play some important roles in metastasis of colorectal carcinoma, andCD44v3 expression might be a new useful independent prognostic marker of colorectal carcinoma.