Clinical usefulness of K-ras gene mutation detection and cytology in pancreatic juice in the diagnosis and screening of pancreatic cancer

Mutations of K-ras gene have been proven to play important roles in human tumor progression. Point mutations of K-ras gene located in codons 61 are gene hot spot mutation regions in patients with gastric cancer. A simple and effective capillary electrophoresis (CE) method for point mutation detection in codon 61 of K-ras gene was established. The polymerase chain reaction (PCR) fragments included codon 61 of K-ras gene were analyzed by single-strand conformation polymorphism (SSCP)-CE method. The CE analysis was performed by using a 1×Tris–borate–EDTA (TBE) buffer containing 3.0% (w/v) poly (ethylene oxide) (PEO) (MW 300 000) under reverse polarity with 15 oC and voltage of 15 kV. Forty-two gastric cancer patients were analyzed using this developed method. K-ras gene mutation was found in 17 cases (40.5 %) and the results showed that K-ras gene mutation in gastric cancer tissue is a usual event, and the SSCP-CE was feasible for mutation detection of K-ras gene in populations. Detection of gene mutation of gastric cancer tissue by PCR - SSCP has a certain value to diagnosis of gastric cancer and to prevent gastric cancer associated with clinical and pathological features, living habits of different patients by detection mutation of K-ras gene codon 61.

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Low Sensitivity of the ki-ras Polymerase Chain Reaction for Diagnosing Pancreatic Cancer From Pancreatic Juice and Bile: A Multicenter Prospective Trial

Journal of Clinical Oncology ◽

10.1200/jco.2002.06.068 ◽

2002 ◽

Vol 20 (21) ◽

pp. 4331-4337 ◽

Cited By ~ 32

Author(s):

Lorenz Trümper ◽

Markus Menges ◽

Heiner Daus ◽

Daniel Köhler ◽

Jan-Olaf Reinhard ◽

...

Keyword(s):

Pancreatic Cancer ◽

Polymerase Chain Reaction ◽

Sensitivity And Specificity ◽

Pancreatic Juice ◽

Prospective Trial ◽

Pcr Analysis ◽

Duodenal Juice ◽

Chain Reaction ◽

Ras Gene ◽

Polymerase Chain

PURPOSE: Early detection of pancreatic cancer using molecular markers may improve outcome. Mutations of the ki-ras oncogene are detected in 70% to 90% of pancreatic adenocarcinomas. A prospective, partially blinded, multicenter diagnostic trial was performed to test the sensitivity and specificity of the ki-ras polymerase chain reaction (PCR) analysis of pancreatic juice and bile specimens. PATIENTS AND METHODS: Specimens of pancreatic juice and bile were collected from 532 consecutive patients. Mutations in codon 12 of the ki-ras gene were identified by two independent enrichment PCRs and confirmed by direct sequencing. RESULTS: One hundred seventy-four of 532 patients were excluded from the final analysis (reasons: no amplifiable DNA, no specimen or only duodenal juice sent, lost to follow-up). Sixty-three of 358 patients had ductal pancreatic cancer. In 24 (38.1%) of 63 patients, a mutated ki-ras gene was identified in pancreatic juice and/or bile. Ki-ras mutations were found in four (8%) of 50 cases of chronic pancreatitis, in 10 (18.7%) of 53 cases of other malignancies of the pancreaticobiliary tree, and in 14 (7.3%) of 192 cases of benign diseases or normal findings. Sensitivity and specificity of the ki-ras PCR analysis for the detection of pancreatic cancer was 38.1% and 90.5%, respectively. CONCLUSION: In this prospective trial performed in nonselected patients, mutations of the ki-ras gene were detected in 38.1% of cases with pancreatic cancer. This test in its present form is not appropriate to confirm or screen for pancreatic cancer. More sensitive and/or quantitative PCR tests may improve the molecular diagnosis of pancreatic cancer.

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