Expression of MUC1 and MUC2 in Ampullary Cancer

Background. Mucins are high-molecular-weight glycoproteins that play important roles in carcinogenesis or tumor invasion. The authors investigated the expression of mucins in ampullary cancer. Methods. MUC1 and MUC2 expressions were examined using immunohistochemistry. Tissue samples were obtained from 32 patients with ampullary cancer who underwent resection at Yamagata University Hospital, Japan. The authors classified the cases with ampullary cancer into 2 subtypes—pancreatobiliary type (PB type) and intestinal type (I type)—using H&E, MUC1, and MUC2 staining. Then, the authors made a comparison of the clinicopathologic data of the 2 subtypes. Results. Fourteen patients (44%) were classified as PB type and 18 patients (56%) as I type. The PB-type group had significantly worse histopathologic characteristics than the I-type group in nodal involvement (PB type 57% vs I type 22%; P = .04), perineural invasion (PB type 50% vs I type 17%; P = .04), duodenal invasion (PB type 100% vs I type 33%; P = .01), and pancreatic invasion (PB type 71% vs I type 33%; P = .03). The PB-type group had significantly worse outcome than the I-type group (5-year survival: PB type 40% vs I type 72%; P = .03). Conclusion. PB-type ampullary cancers were more aggressive than I-type carcinomas. MUC1 and MUC2 expression was useful for classification as PB or I type.