IT HAS LONG been suspected that cancers may be disseminated through the bloodstream by the trauma of surgical removal. In 1913, Tyzzer, 5 after investigating cancer of the breast in mice, suggested that surgeons should consider cancers of the breast" explosive" and handle them accordingly. In 1952, Barnes 1 described a special technic for resecting the right side of the colon for cancer. He advocated ligation of the vascular pedicles and division of the bowel before handling the cancer-bearing seg-ment. In 1954, Cole, Packard, and Southwick2 reported finding cancer cells in the portal venous blood of a perfused resected cancer-bearing segment of human colon. This observation gave rise to their sugges-tion that the vascularpedicle should be ligated before significant operative ma-nipulation is undertaken.