Detection of Point Mutations in the K-ras Oncogene in Pancreatic Juice for Differential Diagnosis between Pancreatic Carcinoma and Chronic Pancreatitis

Oh, Hyung Tae; Roe, Im Hwan; Lee, Myung In; Hwang, Eui Chang; Lee, Moon Sook; Kim, Suk Bae; Song, Il Han; Yang, Mi Ra; Lee, Hak Sung; Lee, Jong Hwa

Abstract

BACKGROUND/AIMS: Mutations in K-ras oncogene at codon 12 are detected in 80-90% of pancreatic carcinomas, which is suggested to be a critical event in the early stage of oncogenesis. The aims of this study were to detect K-ras point mutation in pancreatic juice from pancreatic cancer and chronic pancreatitis and to study whether it could be a useful differential diagnostic method between pancreatic cancer and chronic pancreatitis.
METHODS
Twenty-seven samples of pancreatic juice were obtained from 14 cases of histologically proven pancreatic adenocarcinoma and 13 cases of chronic pancreatitis proven by histology or a minimal follow-up period of 6 months. Then, K-ras mutations were studied using a two-step polymerase chain reaction combined with restriction enzyme digestion (PCR-RFLP).
RESULTS
Mutant K-ras codon 12 in pancreatic juice was found in 11 of 14 (78.6%) cases of pancreatic adenocarcinoma, and in 4 of 13 (30.8%) cases of chronic pancreatitis. For pancreatic carcinoma, the sensitivity, specificity, and accuracy of K-ras mutation analysis were 78.6%, 69.2%, and 74.1%, respectively.
CONCLUSIONS
K-ras analysis is a sensitive method for diagnosing pancreatic carcinoma. However, its specificity is lowered by a high frequency of K-ras mutations in patients with chronic pancreatitis. Therefore, K-ras analysis alone might be insufficient for the differential diagnosis of pancreatic carcinoma from chronic pancreatitis.