Detection of hepatic micrometastasis in pancreatic adenocarcinoma patients by two-stage polymerase chain reaction/restriction fragment length polymorphism analysis.

Hepatic metastasis and retroperitoneal recurrence generally are considered to be the two primary modes of recurrence in pancreatic cancer. The goal of this study was to determine if patients with pancreatic adenocarcinoma have hepatic and peritoneal micrometastasis at operation. Pancreatic adenocarcinomas are known to have a high incidence of K-ras gene mutations. Liver tissue specimens were obtained from 30 patients (17 with pancreatic adenocarcinoma and 13 with other diseases) with a biopsy needle at operation. Peritoneal washings were obtained during operation from 20 patients with pancreatic adenocarcinoma. Two-stage polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis were used to detect K-ras oncogene mutation at codon 12. Thirteen of 17 pancreatic adenocarcinoma patients had K-ras gene mutations in the liver, whereas all 13 patients with other diseases did not. However, only two of 20 pancreatic adenocarcinoma patients revealed K-ras gene mutation in peritoneal lavage fluids. These results indicate the feasibility of detecting hepatic micrometastasis in patients with pancreatic adenocarcinoma, and imply that PCR/RFLP analysis may be of value in the diagnosis, treatment and follow-up of hepatic metastasis of pancreatic adenocarcinoma.