Low frequency of p53 and ras mutations in bile of patients with hepato‐biliary disease: a prospective study in more than 100 patients

Abstract

The diagnosis of biliary disease, namely malignant disorders, is frequently hampered by the inconclusive cytology. We investigated prospectively the frequency of molecular changes in p53 and ras compared with cytology in patients with primary or secondary hepato-biliary disease. We investigated 118 consecutive patients, aged 24-89 with the following clinical diagnoses: choledocho/cholecystolithiasis (28), cholangiocellular carcinoma (21), gall bladder tumor (8), liver metastasis (3), autoimmune disease (8), chronic pancreatitis (16), pancreatic carcinoma (11), papillary disease (4), hepatic cirrhosis (6), cholangitis (2), anomalies (2), and normal (9). Bile was aspirated during routine endoscopic retrograde cholangio pancreatography (ERCP) or percutaneous transhepatic cholangiography (PTC). DNA was prepared freshly from a native aliquot. p53 mutations were detected by polymerase chain reaction (PCR) for exons 5 through 8 followed by TGGE. PCR for ras mutations was performed as RFLP-PCR with sequencing. In four cases, mutations in p53 could be found in exons 6 and 7. Twenty-two samples showed ras mutations; ras mutations were found in choledocholithiasis (4/28), bile duct (5/21), gall bladder (3/8) and pancreatic (1/11) carcinoma, liver metastasis (3/3), ulcerative colitis (2/3), PSC (1/2), and chronic pancreatitis (1/16). Cytology was clearly positive in seven cases, suspicious in three other, inconclusive in six, and negative in the rest. The molecular analysis resulted in a sensitivity of 33% and specificity of 87%, respectively, for the diagnosis of a malignant condition. PCR for p53 and ras mutations may aid the diagnosis of primary and secondary (metastatic) hepatobiliary disease if a malignant condition of the bile ducts and the liver is suspected and cytology is inconclusive or negative. However, the incidence of p53 and ras mutations in bile seems less frequent than in other malignant conditions of the gastrointestinal tract and the pancreas and lower than in tissue, leaving a poor sensitivity and specificity. Nevertheless, the presence of a p53 and/or ras mutation per se supports a clinical suspicion of malignancy, even when the conventional cytology is negative or inconclusive.

The V599E BRAF mutation is uncommon in biliary tract cancers

“…6 Similarly, detection of p53 and RAS gene mutations in bile has a sensitivity of only 33% and a specificity of 87%. 7 There is an ongoing need to identify highly sensitive and specific biomarkers for early detection of biliary tract cancer in biological samples, such as bile or serum.…”

The assessment of TGGE for the detection of interspecific and intergeneric DNA-marker polymorphism within Solanaceae

“…For example, these systems have been used to study bacterial communities (Gomes et al 2001;Brummer et al 2003;Fouratt et al 2003;Nishida et al 2003;Ramirez-Saad et al 2003;Chen and Banks 2004;Haruta et al 2004;Henri-Dubernet et al 2004;Luo et al 2004;Ogier et al 2004;Xu and Leff 2004), and eukaryotic communities (Carlos et al 2000;Hernan-Gomez et al 2000;Anderson and Cairney 2004;Ikenaga et al 2004;Prakitchaiwattana et al 2004;Savin et al 2004). These systems are also commonly used to screen for polymorphisms in human DNA (Toliat et al 2000;Muller et al 2001;Katzke et al 2002;Lage et al 2004;Mihic-Probst et al 2004;Saarikoski et al 2004;Sekiguchi et al 2004;Soufi et al 2004) and less commonly used in wildlife and animal population genetics (Heslewood et al 1998;Jerry and Baverstock 1998;Houlden et al 1999;Leo and Barker 2002;da Mota et al 2004;Westerdahl et al 2004). The author is not aware of any publications that involve the use of TGGE, or other related systems, for the investigation of vascular plants.…”

Rapid Detection of K-ras Mutations in Bile by Peptide Nucleic Acid-mediated PCR Clamping and Melting Curve Analysis: Comparison with Restriction Fragment Length Polymorphism Analysis

“…The presence of K-ras gene mutations in bile, duodenal juice, and pancreatic juice has been used to distinguish benign from malignant biliary strictures (3)(4)(5)(6)(7)(8). Although K-ras mutations have been detected in some patients with benign biliary strictures, such as chronic pancreatitis and gallstones (3,6 ), the detection of such mutations appears to be specific and is considered to be of help in differentiating benign from malignant strictures (3)(4)(5).…”

“…Although K-ras mutations have been detected in some patients with benign biliary strictures, such as chronic pancreatitis and gallstones (3,6 ), the detection of such mutations appears to be specific and is considered to be of help in differentiating benign from malignant strictures (3)(4)(5). Caldas et al (9 ) noted that activating point mutations in codon 12 of the K-ras gene occur in approximately one-half of nonpapillary duct lesions but were present in the majority of papillary, more advanced pancreatic cancers.…”

“…Cholangiocarcinoma also carries K-ras mutations, but the reported frequencies, as assessed in tissue DNA, vary considerably, from 20 -100% in cases in Western countries (10 -12 ) to 5-58% in Japanese cases (13 ). In general, the frequencies of K-ras mutations in biliary duct carcinoma were reported to be 8 -100% in tissue DNA, 5-30% in bile DNA (3,4,10 ), and 42% in brushing fluids (14 ). The point mutations reside mainly in the first two nucleotides of codon 12.…”