The expression of inducible co-stimulator in Egyptian patients with colorectal carcinoma

Abstract

Background and aim In Egypt, colorectal cancer (CRC) constitutes 4.2% of all tumors and comes at rank seventh in males and fourth in female. T and natural killer lymphocytes are considered the main effector players in the immune response against tumors. Co-stimulatory molecules like inducible co-stimulator (ICOS) are crucial in mediating T-cell differentiation and function. The role of ICOS in CRC carcinogenesis and tumor progression is uncertain. The aim of this work is to evaluate the role of ICOS in Egyptian patients with CRC. Materials and methods This retrospective case–control study included 158 colorectal specimens, including 87 chemonaive CRC cases, 12 adenomas, and 59 non-neoplastic colonic tissue cases from Egyptian patients. All cases were stained for ICOS antibody. Results There was no significant difference among the three groups regarding ICOS epithelial and stromal expression. There were significant associations between ICOS epithelial overexpression and well/moderately differentiated CRC cases (P=0.017). However, overexpression of ICOS in the stoma was significantly associated with advanced tumor stage and perineural invasion (P=0.04 and 0.02, respectively). There was no association between expression of ICOS and patients’ overall survival. Conclusion ICOS may not be related to early carcinogenesis. However, stromal ICOS could be incriminated in tumor progression. Therefore, ICOS function might be dual according to its topographic localization (epithelial/stromal).