Published online Mar 1, 2004. doi: 10.3748/wjg.v10.i5.743
Revised: December 22, 2003
Accepted: December 29, 2003
Published online: March 1, 2004
AIM: To study the diagnostic significance of K-ras gene mutations in fecal samples from elderly patients with large intestinal cancer.
METHODS: DNA was extracted in the fecal and tissue samples from 23 large intestinal cancer patients, 20 colonic adenomatoid polypus patients and 20 healthy subjects. The K-ras gene mutations at the first and second bases of codon 12 were detected by the allele specific mismatch method.
RESULTS: The K-ras gene mutation was 56.52% (13/23) in the large intestinal cancer patients, which was notably higher than that in the normal subjects whose K-ras gene mutation was 5% (1/20) (Χ2 = 12.93, P < 0.001). There was no significant difference in comparison with that of colonic adenomatoid polypus patients whose K-ras gene mutation was 30% (6/12) (Χ2 = 3.05, P > 0.05). The K-ras gene mutation at the second base of codon 12 was 92.13% (12/13) in the large intestinal cancer patients. There was no significant difference between the detection rate of K-ras gene mutation in the fecal and tissue samples (Χ2 = 9.35, P < 0.01).
CONCLUSION: Our results indicate that detection of the K-ras gene mutations in fecal samples provides a non-invasive diagnostic method for the elderly large intestinal cancer patients. Its significance in the early diagnosis of large intestinal cancer awaits further studies.