Abstract

Background: Colorectal cancer is one of the commonest malignant tumors among men and women worldwide with large morbidity and mortality 90% of colorectal carcinoma are adenocarcinoma while mucinous type comprising >20% of all colorectal cancers . Development process is slowly with late diagnosis, therefore early detection and screening is of vital importance. CD44, CD166 and ALDH1A1 are stem cell markers with different expressions depending on type of tumor and relation to clinical parameters. Objective: To highlight expression of CD44,CD166 and ALDH1A1 in normal tissue adjacent to mucinous and non-mucinous colorectal adenocarcinoma and correlate with clinic- pathological parameters in a group of Iraqi patients. Methods: A retrospective study of 70 cases with normal tissue adjacent to colorectal carcinoma obtained from two hospitals from 2015 to 2016, divided into two groups. Paraffin blocks were IHC treated with CD44, CD166 and ALDH1A1 markers to compare the expression pattern of these stem cell markers. Results: The study revealed that 15.7 % were mucinous CRC with mean age 59yrs and equal M / F ratio and common site is rectum and recto sigmoidal region .CD44 CD166 and ALDH1A1 markers had different expression pattern among mucinous and non-mucinous CRC. Conclusion: The normal tissue adjacent to CRC had different marker expression properties depending on type of the tumor.