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

Gastrointest Endosc. 1995 Oct;42(4):317-20. doi: 10.1016/s0016-5107(95)70129-x.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bile*
  • Biliary Tract Neoplasms / diagnosis
  • Biliary Tract Neoplasms / genetics
  • Cholangiopancreatography, Endoscopic Retrograde*
  • DNA Mutational Analysis*
  • Genes, ras / genetics*
  • Mutation*
  • Pancreatic Neoplasms / diagnosis
  • Pancreatic Neoplasms / genetics
  • Polymerase Chain Reaction
  • Predictive Value of Tests
  • Prospective Studies
  • Sensitivity and Specificity