Expression of the cancer stem cell markers ABCG2 and OCT-4 in right-sided colon cancer predicts recurrence and poor outcomes

Right-sided colon cancer (RCC) has a poorer prognosis and a higher relapse rate than left-sided colon cancer (LCC). Like cancer stem cells (CSCs), RCC cells cannot be fully eradicated and are often involved in relapse or metastasis. Because CSCs may be linked with poor outcomes, CSC markers may have prognostic value in RCC. ATP-binding cassette sub-family G member 2 (ABCG2) and OCT-4 (also known as POU5F1) are among the most useful markers for CSC identification. We therefore examined the malignant behavior of ABCG2 and OCT-4 in vitro and in vivo, and their expression was assessed in pathology tissues obtained from clinicopathologically recurrent and non-recurrent cases. Our survey suggested associations between ABCG2 and OCT-4 expression and RCC clinicopathological variables. No correlations were detected between ABCG2 or OCT-4 expression and age, gender, tumor size, or tumor shape, but ABCG2 expression correlated with TNM stage, tumor differentiation, and lymphovascular invasion. Additionally, expression of both ABCG2 and OCT-4 correlated with RCC recurrence and poor outcomes.