Pcr Based Mutation Profiling Of Free Dna Enhances Cytology And Fish Based Detection Of Malignancy In Patients With Biliary Structures Undergoing Ercp: A Prospective Study

Routine cytology of biliary stricture brush specimens obtained during standard ERCP has suboptimal sensitivity for malignancy. Recent studies have shown that fluorescence in situ hybridization (FISH) analysis for aneuploidy and PCR-based mutation profiling (MP) for KRAS oncogene mutations and tumor suppressor gene loss of heterozygosity (LOH) mutations can help identify malignancies otherwise undetectable by cytology. Unlike cytology and FISH, MP can be performed on free DNA using residual supernatant preservative fluid that remains after cytocentrifugation of cells from brush specimens. We compared the individual and combined ability of cytology, FISH, and MP to detect malignancy in standard biliary brushings.