Background: Rectal cancer ranks eighth overall whereas colon cancer is the fourth most prevalent cancer worldwide. Incidence instances of colorectal cancer (CRC) were projected to reach 1.9 million in 2020, with 0.9 million deaths. CRC is becoming more common in middle- and low-income countries, where it is more prevalent in developed nations. Colon cancer is the ninth most frequent cancer in Egypt and according to WHO figures. Rectal cancer is the seventeenth most common cancer. CRC is the sixth most prevalent cancer overall.Investigating the relationship between CD44 expression and the clinicopathological characteristics of CRC is the goal of the current investigation.

Methods: Methods: 140 randomly chosen tissue blocks from primary colorectal adenocarcinomas and their lymph nodes were immunohistochemically stained for CD44. Of these, 53 (75.7%) cases were conventional adenocarcinomas (NOS), 7 (10%) were mucinous carcinomas, and 10 (14.3%) were Signet ring carcinomas.

Results: CD44 high expression was detected in 86 (61.4%) of cases. A statistically significant association between CD44 high expression and larger tumor size, higher tumor grade, poorly differentiated clusters (PDCs) grade, regional lymph node involvement, Lymphovascular invasion (LVI) advanced tumor stage, tumor necrosis and tumor infiltrating lymphocytes (P value 0.005*, <0.001*, <0.001*, <0.001*, <0.001*, <0.001*, <0.011 and <0.001*).

Using univariate and multivariate regression analysis. The current study found that tumor grade, PDCs grade, modified Dukes staging and lymphovascular invasion were independently associated with CD44expression (P value 0.008*, 0.009*, 0.007*, 0.001* respectively).

Conclusion: CD44 high expression could be considered as poor prognostic marker in the evaluation of Colorectal Carcinoma.