Purpose: CD44 is a transmembrane protein involving cell proliferation, cell differentiation, cell migration, cell-cell adhesion or cell-matrix interaction. Cleavage of extracellular domain is prominent in human tumors and CD44 standard (CD44st) is the conservative portion. In present study, we evaluated the expression of CD44st in ampullary cancer in order to identify the potential predictor.Materials and
Methods: The paraffin blocks of ampullary neoplasms surgically resected specimens from patients at National Cheng Kung University Hospital between March 1989 and June 2007 was collected. The collected specimens included dysplasia, adenoma, early or advanced adenocarcinoma. Immunohistochemistry (IHC) staining was performed over deparaffinized sections with using anti-human CD44st monoclonal antibody. The expression of CD44st was defined as loss, low or high.
Results: Total 81 patients (41 female and 40 male) were enrolled with average age 63 years, ranged from 32 to 90 years. IHC staining revealed membrane-type staining of CD44st in normal pancreatic duct, but not in normal duodenum. In ampullary neoplasms, diffuse dense membraneous positivity for CD44st was noted in 40 patients (49%), week staining in 24 patients (30%) and complete loss of CD44st in 17 patients (21%). The grading of CD44st staining was not related with age, sex, preoperative tumor markers, tumor size or lymph node involvement. But trends of CD44st loss were detected in tumors with pancreatic invasion or advanced TNM stage. The 5-year disease-specific survival rate was lower in patients with low or negative CD44st expression than those with dense CD44st expression. But in patients without pancreatic invasion, the expression of CD44st represented poor long-term survival, opposite to those with pancreatic invasion.
Conclusion: CD44st expression in patients of early ampullary cancer is a poor predictor, but not in advanced cancer. Dual role of CD44 in ampullary cancer and other malignancies represent the complexities of adhesion molecules in carcinogenesis.