Int J Oncol  1999 Aug;15(2):391-8 

Sampling technique influences the detection of K-ras mutations in normal
appearing mucosa of colorectal cancer patients.

Schimanski CC, Sutter C, Linnemann U, Berger MR.

Unit of Toxicology and Chemotherapy, German Cancer Research Centre, 69120
Heidelberg, Germany.

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.

PMID: 10402253 [PubMed - indexed for MEDLINE]