Diagnostic utility of K-ras mutational analysis on bile obtained by endoscopic retrograde cholangiopancreatography

John G. Lee, Joseph W. Leung, Peter B. Cotton, Lester J. Layfield, Peter J. Mannon

Research output: Contribution to journalArticlepeer-review

39 Scopus citations


Background: Because K-ras oncogene mutations are present in more than 90% of pancreaticobiliary tumors, we tested prospectively whether K-ras mutational analysis of bile samples obtained during ERCP was superior to conventional bile cytology for diagnosis of malignancy. Methods: Bile samples from 20 patients undergoing ERCP for evaluation of jaundice were examined by both cytologic study and the polymerase chain reaction for the presence of K-ras oncogene mutations. Results: Polymerase chain reaction products were amplified from the bile of 8 of 12 patients with malignancy and 3 of 8 with benign disease; K-ras oncogene mutations were present in 4 of 8 polymerase chain reaction products from malignant samples but absent in all 3 from benign samples. No cytologic results were positive for malignancy. Conclusions: Bile obtained during ERCP can yield positive results in K-ras mutational analysis, even when results of conventional bile cytology are negative. In this study, K-ras mutational analysis had a sensitivity of 33% (4 of 12), a specificity of 100%, and a positive predictive value of 100% for diagnosis of malignancy. (Gastrointest Endosc 1995;42:317-20.).

Original languageEnglish (US)
Pages (from-to)317-320
Number of pages4
JournalGastrointestinal Endoscopy
Issue number4
StatePublished - Oct 1995
Externally publishedYes

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Gastroenterology


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