Nm23-H1 protein immunoreactivity in cancers of the gallbladder, extrahepatic bile ducts and ampulla of vater

Immunohistochemical expression of the nm23-H1 protein was investigated in carcinoma of the gallbladder (n=13), common bile duct (n = 5) and ampulla of Vater (n= 7) using the monoclonal antibody, NM 301 (Molecular Oncology Inc.). This was compared with cases of chronic cholecystitis (n = 11) and preneoplastic lesions of the gallbladder (n =4) and ampulla (n =3). Absent or weak nm23-H1 protein immunoreactivity was found in most (67%) of the poorly differentiated adenocarcinomas of the gallbladder and in half of the cases of moderately differentiated adenocarcinomas. The difference in nm23-H1 protein immunostaining between gallbladder carcinoma and chronic cholecystitis was statistically significant (p = 0.0022; X2 test). Significant correlation was found between prolonged patient survival periods and nm23-H1 immunoreactivity in gallbladder carcinomas (R= 0.687, p = 0.01, linear regression analysis; r= 0.652, p = 0.016, Spearman’s rank test). Most of the gallbladder dysplasias and adenomas had no reduction in nm23-H1 protein immunoreactivity. All common bile duct carcinomas, most (67%) ampullary carcinomas in situ and some (43%) ampullary carcinomas had moderate to strong nm23-H1 immunostaining. In summary, low nm23-H1 protein immunoreactivity was found more frequently in gallbladder carcinomas than in chronic cholecystitis and was associated with reduced patient survival. The differences in nm23-H1 protein immunoreactivity in common bile duct and ampullary carcinomas suggest that these tumors have a different molecular origin to gallbladder cancers.