Objective  To investigate the expression and prognostic value of the Oct4 protein in colon cancer.

  Methods  Immunohistochemical technique was used to examine the expression of Oct4 protein in 89 left side colon cancer (LCC) tissues and 77 right-side colon cancer (RCC) tissues. The relationship among Oct4 expression, clinicopathological parameters, and the prognostic value of Oct4 in colon cancer was analyzed.

  Results  The positive rate of Oct4 protein in LCC was 68.54%, and that in RCC was 71.43%. There was no significant difference between the two values. In addition, Oct4 expression in RCC was positively correlated with histological grade, lymph node metastasis, and Dukes staging. By contrast, Oct4 expression in LCC was only positively correlated with histological grade and Dukes staging. In survival analysis, the 5-year survival rate of LCC was significantly higher than that in RCC (P < 0.01). In patients with LCC, no obvious correlation was found between positive and negative Oct4 expression levels in OS. In patients with RCC, Oct4 overexpression indicated poor prognosis (P < 0.05). Also, in Cox survival analysis, Oct4 overexpression indicated poor prognosis in RCC but not in LCC.

  Conclusion  These results indicated that Oct4 plays different roles in LCC and RCC. These roles can be used as theoretical basis for exploring new targets for the diagnosis and treatment of colon cancer.