Evaluation of the role of CD44 as a cancer stem cell marker in colorectal carcinoma: immunohistochemical study

Abstract

Objectives The aim of this work was to study the immunohistochemical expression of CD44 in colorectal carcinoma (CRC) cases. Background Cancer stem cells (CSCs) have a role in cancer initiation, progression, and metastasis of CRC through their ability of self-renewal and unlimited proliferation, and they seem to be responsible for local relapse and metastasis. Several markers for CSCs have been investigated in CRC, and CD44 was the most likely marker for colorectal CSCs. Materials and methods This retrospective study included 71 colorectal specimens (49 CRC, 13 adenoma, and nine normal cases). The studied cases were collected from the Pathology Department, Faculty of Medicine, Menoufia University, during the period from 2011 to 2015. All cases were stained with CD44 antibody. Survival data were available for 31 of 49 studied CRC cases. Results All cases of normal colonic epithelium and normal colon adjacent to CRC showed no membranous CD44 immunoreactivity; 84.6% of the studied adenoma cases showed no expression of CD44, whereas 57.1% of CRC cases showed positive expression. There was a statistically significant association between positive epithelial expression of CD44 and left-sided tumors (P = 0.01). There was a statistically significant difference between CRC and colorectal adenoma (P = 0.007) and between CRC and normal cases (P = 0.000) as regards CD44 expression. There was a highly statistically significant association between stromal expression of CD44 and absence of lymph node invasion (P = 0.002) as well as early Dukes' stage (P = 0.01). Conclusion CD44 may be involved in the pathogenesis of CRC. Stromal expression only of CD44 is associated with better prognostic factors.