The expression of matrix metalloproteinases in intrahepatic cholangiocarcinoma, hilar (Klatskin tumor), middle and distal extrahepatic cholangiocarcinoma, gallbladder cancer, and ampullary carcinoma: role of matrix metalloproteinases in tumor progression and prognosis.

BACKGROUND/AIMS: Carcinomas of the biliary tree are rare tumors of the gastrointestinal tract, with an increasing incidence in recent years. Biliary neoplasms are classified into intra- and extrahepatic cholangiocarcinoma (Klatskin tumor, middle and distal extrahepatic tumors), gallbladder adenocarcinoma, and ampullary carcinoma. We aimed to determine the expression profile of matrix metalloproteinase (MMP)-2, MMP-9 and MMP-14 in the biliary neoplasms classified according to their localization and the relation with the prognosis.

METHODS

Ten gallbladder adenocarcinoma, 8 distal bile duct carcinomas (distal cholangiocarcinoma), 8 Klatskin tumors, 8 intrahepatic cholangiocarcinomas and 10 ampullary carcinomas were included in the study. The immunohistochemical expression of MMP-2, MMP-9 and MMP-14 was detected in the nontumoral, metaplastic, dysplastic and tumoral epithelia. The tumor differentiation, angiolymphatic and perineural invasion of the tumor, and presence of lymph node and distant metastasis were determined. Survey of the patients was noted from the patient follow-up data.

RESULTS

The nontumoral epithelia of the gallbladder, intrahepatic ducts, and Klatskin tumor did not express MMP-2. MMP-2 expression was detected in the distal part of the biliary ducts, in 75% (6/18) of cases and in the nontumoral epithelia of the ampullary region in 50% (5/10) of cases. The metaplastic and dysplastic epithelia were positively stained in all of the gallbladder adenocarcinoma, distal cholangiocarcinoma and ampullary tumors. In the intrahepatic cholangiocarcinoma, the hepatocytes were positively stained but the infiltrative tumors were spared. Klatskin tumors were also not stained with MMP-2. The gallbladder adenocarcinoma, distal cholangiocarcinoma and ampullary carcinomas expressed MMP-2 in 30%, 37% and 40% of the cases, respectively. MMP-9 and MMP-14 were expressed in normal, metaplastic, and dysplastic epithelium and tumoral cells in all of the cases of the groups. Expressions of MMPs were higher in subjects with neural invasion, but there was no correlation between MMP expression and tumor differentiation or angiolymphatic invasion.

CONCLUSIONS

When tumors of the biliary system are divided as intrahepatic and extrahepatic cholangiocarcinomas, MMP-2 expression was present in the extrahepatic cholangiocarcinomas including gallbladder carcinomas. Like the intrahepatic cholangiocarcinoma, Klatskin tumors also did not express MMP-2. This can be related with its characteristic growth pattern. MMP-9 and MMP- 14 were present in metaplasia, dysplasia carcinoma sequence in all of the bile tract tumors, suggesting that MMPs play an important role in carcinogenesis. The higher expression of the MMPs with neural invasion suggests the significant role of those tumors in the invasion activity.