Clinical significance of K-Ras mutations in intraoperative tumor drainage blood from patients with colorectal carcinoma.
BACKGROUND
Recurrent and metastatic carcinoma of the colorectum remains a major problem. This may be ascribed to the presence of micrometastasis at diagnosis. The purpose of this study was to analyze prospectively the clinical value of detecting K-ras mutations in the perioperative circulating blood from patients with colorectal carcinoma.


METHODS
Twenty-four patients whose tumor carried mutations in codon 12 of the K-ras gene were studied for the presence of cancer cells in perioperative blood samples, in particular, tumor drainage samples. A detection assay using CD45 immunomagnetic separation plus nested mutant allele specific amplification (MASA) was performed.


RESULTS
K-ras mutations in CD45 negative cells in tumor drainage blood were detected in 7 (29.2%) of 24 patients. There was no significant relationship between the presence of a K-ras mutation and clinicopathological features. Four (57.1%) of the seven patients with a positive K-ras mutation in drainage blood had early recurrent disease. Of the 17 patients with no K-ras mutation, none developed metastatic disease. The recurrence rate of the K-ras mutation positive group was higher than that of the K-ras mutation negative group (P < .01). There was a significant difference, regarding prognosis, between K-ras mutation positive and negative groups (P < .01).


CONCLUSIONS
This preliminary study demonstrates that the detection of circulating cancer cells in the tumor drainage blood by our new assay system may provide a predictor of recurrence and metastasis of colorectal cancer.
Etoh
T
T
Department of Surgery, Medical Institute of Bioregulation, Kyushu University, Beppu, Japan.
Ueo
H
H
Inoue
H
H
Sato
K
K
Utsunomiya
T
T
Barnard
G F
GF
Kitano
S
S
Mori
M
M
D000230:Adenocarcinoma / Q000097:blood* / Q000235:genetics* / Q000473:pathology; D000368:Aged; D015179:Colorectal Neoplasms / Q000097:blood* / Q000235:genetics* / Q000473:pathology; D004322:Drainage; D005260:Female; D011905:Genes, ras / Q000235:genetics*; D006801:Humans; D007432:Intraoperative Period; D017493:Leukocyte Common Antigens / Q000097:blood; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D009360:Neoplastic Cells, Circulating / Q000473:pathology; D016019:Survival Analysis; D016896:Treatment Outcome
D017493:Leukocyte Common Antigens