Characterization of CD24 expression in intraductal papillary mucinous neoplasms and ductal carcinoma of the pancreas

CD24 is a molecule involved in cell adhesion and tumor metastasis. The aims of this study were (1) to evaluate the association between CD24 expression and the progression of intraductal papillary mucinous neoplasms of the pancreas and (2) to investigate the association between CD24 expression in pancreatic cancer and the prognosis of patients who underwent curative pancreatectomy. Immunohistochemical analysis of CD24 was performed for 95 intraductal papillary mucinous neoplasms of the pancreas and 83 pancreatic cancers. We investigated the association between CD24 expression and the histologic grade of intraductal papillary mucinous neoplasms of the pancreas, the clinicopathologic parameters of pancreatic cancers, and the survival time of pancreatic cancer patients who underwent pancreatectomy. The positive rates of CD24 expression in intraductal papillary mucinous adenoma, borderline intraductal papillary mucinous neoplasm, noninvasive intraductal papillary mucinous carcinoma, and invasive intraductal papillary mucinous carcinoma were 5 (20%) of 24, 12 (48%) of 25, 10 (43%) of 23, and 15 (65%) of 23, respectively. The CD24-positive rates were significantly higher in borderline intraductal papillary mucinous neoplasm and intraductal papillary mucinous carcinoma compared with intraductal papillary mucinous adenoma (P = .046 and P = .007, respectively). The staining scores, which were determined from the percentage of stained cells and the staining intensity, were significantly higher in invasive intraductal papillary mucinous carcinoma than in noninvasive intraductal papillary mucinous carcinoma (P = .043). In the pancreatic cancers, higher tumor stage (P = .007), nodal metastasis (P = .021), and higher-grade tumors (P < .001) were more frequent in the CD24-positive group compared with the CD24-negative group. CD24 expression was associated with shorter survival in univariate analysis (P = .028) However, based on the multivariate analysis, the CD24 expression was not associated with survival. In conclusion, CD24 is involved in the progression of intraductal papillary mucinous neoplasms of the pancreas and in the malignant behavior of pancreatic cancers.