Expression and clinical significance of colorectal cancer stem cell marker EpCAM^high/CD44⁺ in colorectal cancer

Colorectal cancer stem cells are considered the source of recurrence, metastasis and drug resistance in colorectal tumors. Therefore, the identification and targeting of cancer stem cells facilitates the elimination of tumors. Although epithelial cell adhesion molecule-high (EpCAM^high)/cluster of differentiation (CD)44⁺ cells are thought to act as a marker of colorectal cancer stem cells, the clinical significance of these cells in colorectal cancer remains unclear. The aim of the present study was to explore the prevalence and clinical significance of colorectal cancer stem cell marker EpCAM^high/CD44⁺ in colorectal cancer. Double immunohistochemical staining was used to detect the expression of EpCAM/CD44 in 80 cases of colorectal cancer and their corresponding liver metastases. The expression of EpCAM/CD44 in colorectal cancer was analyzed, and the correlation of EpCAM^high/CD44⁺ with the biological behavior of colorectal cancer was explored. In the 80 cases of colorectal cancer studied, the presence of EpCAM^high/CD44⁺ cells had no correlation with gender, patient age or the magnitude of the tumor (P>0.05), but was significantly correlated with degree of differentiation, depth of invasion, clinical stage and metastatic status (P<0.05). In addition, EpCAM^high/CD44⁺ cells were detected in the corresponding liver metastases. Thus, the results of this study indicate that EpCAM^high/CD44⁺, a marker of colorectal cancer stem cells, is significantly correlated with the invasion and metastases of colorectal cancer.