Experimental evidence does not support use of the "no-touch" isolation technique in colorectal cancer.
OBJECTIVE
The benefits of the "no-touch" isolation technique usually performed to prevent the circulation of tumor cells are not evident. The aim of this study was to determine whether conventional surgical procedures for treatment of colon cancer could provoke the circulation of tumor cells detected by a genetic technology.


METHODS
Sixteen patients undergoing resection for colorectal cancer and two patients with irresectable tumors were studied. No patient showed liver or lung metastasis. With specific primers for carcinoembryonic antigen, we used reverse transcriptase-polymerase chain reaction to analyze tumor biopsy specimens and blood samples obtained from the antecubital vein before and after surgery and from the main drainage vein of the tumor when the tumor had been extracted. Peritoneal fluid was also collected in irrecsectable cases.


RESULTS
Amplification of cDNA with carcinoembryonic antigen-specific primers was achieved with all tumor biopsies and samples of peritoneal fluid. In two patients carcinoembryonic antigen reverse transcriptase-polymerase chain reaction products were detected in antecubital vein blood before surgery and in one of them also after surgery. Only in one patient (Dukes C) were carcinoembryonic antigen reverse transcriptase-polymerase chain reaction products detected from the main drainage vein of the tumor. In serial dilution experiments we determined that the limit of detection of this method was ten tumor cells in 2 ml of blood.


CONCLUSIONS
Our data suggest that the use of no-touch isolation techniques in colorectal cancer is not justified, based on lack of evidence indicating the detachment of cells from the tumor at surgery.
García-Olmo
D
D
Department of General Surgery, Albacete General Hospital, Spain.
Ontañón
J
J
García-Olmo
D C
DC
Vallejo
M
M
Cifuentes
J
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001202:Ascitic Fluid / Q000378:metabolism / Q000473:pathology; D001706:Biopsy; D002272:Carcinoembryonic Antigen / Q000235:genetics / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism / Q000601:surgery*; D013505:Digestive System Surgical Procedures / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating / Q000378:metabolism / Q000473:pathology; D011183:Postoperative Complications; D012333:RNA, Messenger / Q000032:analysis; D012334:RNA, Neoplasm / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity
D002272:Carcinoembryonic Antigen; D012333:RNA, Messenger; D012334:RNA, Neoplasm