k‐ras Point Mutations in the Supernatants of Pancreatic Juice and Bile Are Reliable for Diagnosis of Pancreas and Biliary Tract Carcinomas Complementary to Cytologic Examination

Abstract

In order to clarify whether DNA analysis for K-ras mutation can be used to diagnose cancers in supernatants of pancreatic juice and bile, samples from 29 cases of pancreatic, biliary tract, gastric, and neuroendocrine carcinomas, 1 malignant lymphoma case, 2 cases of pancreatic adenoma, 9 cases of chronic pancreatitis and 21 other non-cancer cases were examined. Polymerase chain reaction (PCR) products for K-ras gene codons 2 to 97 of exons 1 and 2 were generated with 33/33 (100%) pancreatic juice and 41/41 (100%) bile samples. By the single strand conformation polymorphism (SSCP) method, point mutations were detected in the pancreatic juice or bile supernatants of 13/13 (100%) pancreas cancer cases, 5/14 (35.7%) biliary tract cancer cases, 1/2 (50.0%) pancreatic adenoma cases and 3/9 (33.3%) chronic pancreatitis cases. Direct sequencing confirmed identical point mutations in the supernatants, malignant cells of cytologic smears of pancreatic juice or bile and cancer tissues. The DNA analysis demonstrated the presence of K-ras point mutations in 3 cases of pancreatic carcinomas with false-negative cytologic diagnoses. This novel method allows simultaneous testing for genetic abnormalities in supernatants of pancreatic juice and bile, after removing cells for cytologic diagnosis and screening for pancreatic and biliary tract tumors.

Detection of Micrometastases in Peritoneal Washings of Pancreatic Cancer Patients by the Reverse Transcriptase Polymerase Chain Reaction

“…Kras mRNA was found by RT-PCR in 89% of ascites supernatants of patients with pancreatic carcinoma. 11 Our study successfully detected mRNA of tumor markers overly expressed in peritoneal washes of pancreatic cancer patients. The level at which to cut off cycle amplification was determined by using a receiver operating characteristic (ROC) curve.…”

“…[7][8][9][10] Detection of Kras mRNA by PCR has been shown to have a sensitivity of 89% in ascites supernatants of patients with pancreatic carcinoma. 11 Carcinoembryonic antigen (CEA) and CK20 have been detected by immunohistochemistry in patients with metastatic pancreatic adenocarcinoma at a sensitivity rate of 92 and 78%, respectively. 12 Likewise, MUC1 and cytokeratin 7 (CK7) have been shown to be positive in 89 and 91% of patients with pancreatic cancer, respectively.…”

Usefulness of p53 gene mutations in the supernatant of bile for diagnosis of biliary tract carcinoma: comparison with K- ras mutation

“…᭹, p53 and K-ras mutant; , p53 mutant only; ᭺, K-ras mutant only; ᭝, p53 and K-ras wild-type al. 6 and the authors 7 of this article found that the incidence of K-ras mutations in PCa was higher in the Sup than the Sed of PJ, suggesting that the Sup of body fluids is useful for genetic analysis. To improve the molecular diagnosis of BTCa, we analyzed gene mutations in DNA extracts not only from the Sed but also from the Sup of bile samples.…”

“…Recently, Yamashita et al 6 and the authors 7 of this article found that the incidence of K-ras mutations in pancreatic cancer (PCa) was higher in the supernatant (Sup) than in the sediment (Sed) of pancreatic juice (PJ), suggesting the usefulness of Sup from body fluids for genetic analysis.…”

DNA Ploidy and Markovian Analysis of Neoplastic Progression in Experimental Pancreatic Cancer

“…Interestingly, although K-ras mutations have been observed in human chronic pancreatitis (Yanagisawa et al 1993), p53 mutations were not observed in chronic pancreatitis but were commonly observed in pancreatic cancer (Casey et al 1993). Analysis of K-ras point mutations in pancreatic juice can be a reliable diagnostic indicator of pancreatic and biliary tract carcinomas (Yamashita et al 1999). Abnormalities in DNA mismatch repair genes, such as hMLH1 and hMSH2, are seen in more than 90% of hereditary nonpolyposis colorectal cancers and are believed to constitute an initial abnormality that facilitates mutations in other genes and leads to adenocarcinoma development (Fishel et al 1993;Papadopoulos et al 1994).…”