Sampling technique influences the detection of K-ras mutations in normal appearing mucosa of colorectal cancer patients.
Based on three colorectal cancer cell lines with specified K-ras status, a sensitive PCR-RFLP assay was established detecting one K-ras mutant among 106 wild-type cells. Using this assay for tissues of 124 colorectal cancer patients, 59 tumor (46%) and 11 mucosa samples (9%) were found to harbor a K-ras mutation. When using the same scalpel for collecting tumor and mucosa tissues (group A), 18% of the patients had a matching K-ras mutation in both tissues, but this coincidence was seen in 3% of patients only, when separate scalpels were used (group B). Thus we conclude that the sampling technique used for collecting specimens is a major contributor to the detection of K-ras mutations in normal appearing mucosa when a highly sensitive detection technique is used.
Schimanski
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CC
Unit of Toxicology and Chemotherapy, German Cancer Research Centre, 69120 Heidelberg, Germany.
Sutter
C
C
Linnemann
U
U
Berger
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MR
D000368:Aged; D015179:Colorectal Neoplasms / Q000235:genetics*; D005260:Female; D011905:Genes, ras; D006801:Humans; D007413:Intestinal Mucosa; D008297:Male; D009154:Mutation; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012016:Reference Values; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D013048:Specimen Handling / Q000379:methods*; D014407:Tumor Cells, Cultured