Expression of integrins in intraductal papillary-mucinous tumors of the pancreas as an indicator of malignancy.

INTRODUCTION AND AIMS

Intraductal papillary-mucinous tumors (IPMTs) of the pancreas are intraductal tumors with diffuse or segmental dilation of the pancreatic ducts and intraductal papillary growth with abundant mucous secretion. We examined clinicopathological features and immunohistochemical findings to investigate the malignancy of IPMTs.

METHODOLOGY

Between April 1994 and December 2002, 23 patients with IPMT underwent pancreatic resections at Nagoya City University Hospital, Japan. We immunohistochemically analyzed the expression of p53 protein, proliferating cell nuclear antigen, alpha6-integrin subunit, alpha5beta1 integrin, and interleukin-1 receptor type I in tumor specimens from the 23 patients with IPMT.

RESULTS

The tumors were classified as intraductal papillary adenoma (n = 16), intraductal papillary adenocarcinoma and moderate dysplasia (n = 7). At a median follow-up of 42.9 months, 2 patients had died of this disease. The actuarial 5-year disease-free survival rate was 80.7%. Expression of the alpha6-integrin subunit was significantly strong in adenocarcinoma and moderate dysplasia tissues of IPMTs (P = 0.038).

CONCLUSIONS

Our current results indicate that alpha6-containing integrin expression can be a significant marker of malignancy in IPMTs. We emphasize that immunohistochemical investigation of resected specimens is indispensable in cases of IPMT, so that appropriate postoperative treatments for malignant IPMTs are initiated to improve prognosis.