Prognostic significance of K-ras mutations in colorectal carcinoma.
BACKGROUND
Mutations at codons 12, 13, and 61 of the ras genes have been found in a variety of human tumors and may have prognostic significance. K-ras mutations have been shown in 40%-50% of colorectal cancers.


METHODS
Using a simple nonradioactive polymerase chain reaction-based technique, we have investigated the possible prognostic significance of point mutations of the K-ras gene in patients with human colorectal carcinomas. The prevalence and the type of ras mutations were compared between a group of 35 patients having recurrent disease within 5 years and a group of 64 patients who were disease free 5 years following surgery.


RESULTS
First, we found that the overall prevalence of mutations within codons 12 and 13 of the K-ras gene was 25% in the nonrecurring group vs. 71% in the patients with recurrent disease (P < 0.0001) and, second, that mutations other than GGT to GAT occurred, with one exception, exclusively in recurring tumors.


CONCLUSIONS
In Dukes' B and C primary tumors, mutations other than GGT to GAT identify patients at very high risk for recurrence. Our results indicate that determining the K-ras mutations provides a good prognostic factor in patients with advanced colorectal carcinoma.
Benhattar
J
J
Institut Universitaire de Pathologie, Lausanne, Switzerland.
Losi
L
L
Chaubert
P
P
Givel
J C
JC
Costa
J
J
D000328:Adult; D000367:Age Factors; D000368:Aged; D001483:Base Sequence; D003062:Codon / Q000235:genetics; D003110:Colonic Neoplasms / Q000235:genetics* / Q000473:pathology; D005260:Female; D011905:Genes, ras; D006683:HLA-DQ Antigens / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009362:Neoplasm Metastasis / Q000235:genetics / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000235:genetics / Q000473:pathology; D009367:Neoplasm Staging; D009838:Oligodeoxyribonucleotides; D017354:Point Mutation; D011379:Prognosis; D012004:Rectal Neoplasms / Q000235:genetics* / Q000473:pathology; D012008:Recurrence
D003062:Codon; D006683:HLA-DQ Antigens; D009838:Oligodeoxyribonucleotides