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

Background The diagnosis of biliary disease, namely malignant disorders, is frequently hampered by the inconclusive cytology. We investigated prospect ively the frequency of molecular changes in p53 and ras compared with cytol ogy in patients with primary or secondary hepato-biliary disease. Material and methods We investigated 118 consecutive patients, aged 24-89 w ith the following clincal diagnoses: choledocho/cholecystolithiasis (28), c holangiocellular 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), anoma lies (2), and normal (9). Bile was aspirated during routine endoscopic retr ograde cholangio pancreatography (ERCP) or percutaneous transhepatic cholan giography (PTC). DNA was prepared freshly from a native aliquot. p53 mutati ons 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 sequ encing. Results In four cases, mutations in p53 could be found in exons 6 and 7. Tw enty-two samples showed ras mutations; ras mutations were found in choledoc holithiasis (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 ca ses, suspicious in three other, inconclusive in six, and negative in the re st. The molecular analysis resulted in a sensitivity of 33% and specificity of 87%, respectively, for the diagnosis of a malignant condition. Conclusion PCR for p53 and ras mutations may aid the diagnosis of primary a nd 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 les s frequent than in other malignant conditions of the gastrointestinal tract and the pancreas and lower than in tissue, leaving a poor sensitiviy and s pecificity. Nevertheless, the presence of a p53 and/or ras mutation per se supports a clinical suspicion of malignancy, even when the conventional cyt ology is negative or inconclusive.