Low expression of claudin-1 and presence of poorly-differentiated tumor clusters correlate with poor prognosis in colorectal cancer.

Background: Claudins are integral membrane proteins that constitute tight junctions. The aim of this study was to determine the clinical significance of claudin-1 in terms of the cell-cell adhesion, considering the poorly-differentiated tumor component.

Patients And Methods: A total of 344 cases of stage II and III colorectal cancer were enrolled. We evaluated the expression of claudin-1 by immunohistochemistry and the extent of the poorly differentiated component.

Results: Low expression of claudin-1 was associated with lymphatic involvement, histological differentiation, extent of poorly-differentiated component, reduced disease-free and overall survival. Multivariate analysis indicated that lymph node metastasis, venous involvement and low claudin-1 expression were independent predictors of recurrence, and that lymph node metastasis, venous involvement and low claudin-1 expression were associated with poor survival.

Conclusion: Our study not only showed the significance of low expression of claudin-1 as a predictor of poor prognosis of colorectal cancer but also supported the concept of grading of the poorly-differentiated component.