Cluster of Differentiation 44 Expression in Gastrointestinal Malignancies: A Study from South India.

Cancer stem cell markers are now being tried in various cancers as prognostic markers including GI cancer but these kinds of studies are sparse in Indian population.  This study conducted over a period 50 months. Hematoxylin and eosin-stained slides were screened for grading of the tumor, extent of invasion of tumor, confirmation of metastasis, and staging was done. Immunohistochemical expression of CD44 was graded on the basis of percentage of tumor cells positive for staining. Statistical analysis was done and results were tabulated. : A total of 40 cases of GI cancer were studied. Ascending colon (37.5%) was the common site involved, 37 cases (92.5%) showed invasion beyond the muscularis externa. Most tumors were poorly differentiated (37.5%). Also, 50% of lymph nodes showed tumor deposits. The majority of the cases were in stage II (40%). There was a significant correlation between histopathological type of differentiation with lymph node metastasis and staging of tumor, lymph node metastasis also had significant association with staging. Grade 2, CD 44 expression was most common followed by Grade 3. Significant association was observed between histopathological differentiations of tumor with CD44 expression. Tumors that are invading beyond muscularis externa and lymph node-positive cases showed moderate to high CD44 expression.  CD44 expression was significantly noted in poorly differentiated tumors. Increased expression was also noted in cases of tumors invading beyond muscularis externa and lymph node metastasis. Combination of CSC markers will increase the sensitivity and specificity and predict better overall survival in GI tumors.