Clinical Value of Human Leucocyte Antigen G (HLA-G) Expression in the Prognosis of Colorectal Cancer

Objectives: Overexpression of human leukocyte antigen G (HLA-G) in several malignant tumors has been reported. The aim of our study was to investigate HLA-G expression in colorectal cancer tumors and determine HLA-G expression relation between clinico-pathological characteristics and survival time. Methods: HLA-G expression was evaluated by immunohistochemistry (IHC) using anti-HLA-G antibody in 100 primary tumors of colorectal cancer with different stages. Results: Our results showed that 25% of the colorectal cancer tissues had positive HLA-G expression and 75% no stained with anti-HLA-G antibody. The HLA-G expression in advanced stages (III and IV) was more prevalent than those in earlier clinical stages (I and II) (P = 0.0001). Results showed that HLA-G expression can serve as an independent factor for overall survival (OS). In this study, patients with HLA-G expression had significantly shorter survival time than those with negative expressions (P = 0.023). Conclusions: HLA-G expression can serve as an independent factor for OS and its expression may be directly related to aggressive tumor behavior via escape from the host antitumor immune defense. Protein expression of HLA-G correlates with poor prognosis in colorectal cancer.