The role of CD24 in various human epithelial neoplasias.

CD24 is a small, heavily glycosylated glycosylphosphatidylinositol-linked cell surface protein, which is expressed in hematologic malignancies and in a large variety of solid tumors. It appears to function as a ligand of P-selectin, an adhesion molecule present in activated platelets and endothelial cells. The authors aimed at evaluating CD24 protein expression in adenoma and adenocarcinoma of the stomach, colon, gallbladder, ovary, and breast to establish a correlation with clinicopathologic data. Staining was evaluated using four degrees of positivity (negative, weakly, moderately, strongly positive), and the staining patterns (membranous vs. intracytoplasmic) were analyzed for statistical analysis. The present study clearly demonstrates that CD24 is abundantly expressed in adenocarcinoma compared to adenoma of the colon and breast. Moreover, the positivity degree of CD24 expression increases with positive nodal status in advanced gastric carcinoma. Intracytoplasmic CD24 expression was found to be highly associated with adenocarcinoma of the colon, gallbladder, and ovary compared to the adenoma group of those organs, and with the positive nodal status compared to the negative nodal status of the colonic adenocarcinoma. We conclude that the degree of positivity and the staining pattern of CD24 constitute an important molecular marker for various epithelial neoplasms, which could help to define malignant transformation and to predict lymph node metastasis.