Molecular diagnosis of exocrine pancreatic cancer using a percutaneous technique. Ann Surg Oncol 1996 May;3(3):241-6
Date
05/01/1996Pubmed ID
8726178DOI
10.1007/BF02306278Scopus ID
2-s2.0-0030141217 (requires institutional sign-in at Scopus site) 23 CitationsAbstract
BACKGROUND: The K-ras oncogene is activated by point mutations at codon 12 in most patients with exocrine pancreatic cancer. Mutant-enriched polymerase chain reaction (PCR) amplification can enhance the detection of mutated K-ras. This technique was applied to patients undergoing percutaneous fine-needle aspiration (FNA) biopsy of suspect pancreatic lesions.
METHODS: Twenty-five patients underwent percutaneous FNA of the pancreas for cytologic and molecular analysis. After preparing cytologic smears, the 22-gauge needle and syringe used for FNA were rinsed in RPMI-1640. The specimen was centrifuged, and DNA was extracted from the supernatant and subjected to mutant-enriched PCR using appropriate mismatched primers that introduce a BstNI restriction endonuclease clevage site at codon 12 of wild-type, but not mutant, K-ras. After digestion with BstNI, the DNA was reamplified. To increase assay sensitivity, the final five PCR cycles were completed incorporating 5 microCi of (alpha-32P)dCTP. The DNA was then redigested and subjected to gel electrophoresis and autoradiography.
RESULTS: The median amount of DNA retrieved per specimen was 3.33 micrograms. Mutant K-ras was detected as a band of 143 bps; residual wild-type DNA was seen as a 114-bp fragment. Twenty-one of 25 specimens demonstrated mutated K-ras DNA. Two patients with nondiagnostic cytology results had mutated K-ras DNA; adenocarcinoma of pancreatic origin was confirmed in both cases after pancreatectomy.
CONCLUSION: The molecular diagnosis of pancreatic cancer through identifications of mutations in K-ras can be readily performed on specimens obtained by percutaneous FNA. As aggressive multimodality management of this disease becomes more common, pretreatment analysis of molecular determinants may have greater clinical significance.
Author List
Evans DB, Frazier ML, Charnsangavej C, Katz RL, Larry L, Abbruzzese JLAuthor
Douglas B. Evans MD Chair, Professor in the Surgery department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdenocarcinomaBase Sequence
Biopsy, Needle
Codon
DNA Mutational Analysis
Feasibility Studies
Genes, ras
Humans
Molecular Sequence Data
Pancreas
Pancreatic Neoplasms
Point Mutation
Polymerase Chain Reaction
Predictive Value of Tests