K-ras mutations in stools and tissue samples from patients with malignant and nonmalignant pancreatic diseases.

Mutant-enriched PCR and reverse dot blot hybridization in microplates were applied for examining K-ras status in stools and tissue samples from patients with pancreatic tumors and chronic pancreatitis. In tissue samples, K-ras mutations were found in 32 of 35 cases of ductal adenocarcinoma, in 5 of 7 periampullary cancers, in 1 cystadenocarcinoma, and in 3 of 5 patients with chronic pancreatitis. In stools, mutated K-ras was seen in 10 of 25 cases of ductal adenocarcinoma, in 1 case of cystadenocarcinoma, and in 2 of 6 cases of chronic pancreatitis. These data indicate that the K-ras status of stool samples may help identify pancreatic carcinoma and persons at risk for cancer development; however, it does not allow discrimination of malignant from nonmalignant diseases.