Experimental evidence does not support use of the "no-touch" isolation technique in colorectal cancer

PURPOSE: The benefits of the "no-touch" isolation technique usually perform ed to prevent the circulation of tumor cells are not evident. The aim of th is study was to determine whether conventional surgical procedures for trea tment of colon cancer could provoke the circulation of tumor cells detected by a genetic technology. METHODS: Sixteen patients undergoing resection fo r colorectal cancer and two patients with irresectable tumors were studied. No patient showed liver or lung metastasis. With specific primers for carc inoembryonic antigen, we used reverse transcriptase-polymerase chain reacti on to analyze tumor biopsy specimens and blood samples obtained from the an tecubital vein before and after surgery and from the main drainage vein of the tumor when the tumor had been extracted. Peritoneal fluid was also coll ected in irrecsectable cases. RESULTS: Amplification of cDNA with carcinoem bryonic antigen-specific primers was achieved with all tumor biopsies and s amples of peritoneal fluid. In two patients carcinoembryonic antigen revers e transcriptase-polymerase chain reaction products were detected in antecub ital vein blood before surgery and in one of them also after surgery. Only in one patient (Dukes C) were carcinoembryonic antigen reverse transcriptas e-polymerase chain reaction products detected from the main drainage vein o f the tumor. In serial dilution experiments we determined that the limit of detection of this method was ten tumor cells in 2 mi of blood. CONCLUSION: Our data suggest that the use of no-touch isolation techniques in colorect al cancer is not justified, based on lack of evidence indicating the detach ment of cells from the tumor at surgery.