Implantation metastasis as a cause of local recurrence of colorectal carcinoma.

Local recurrence of colorectal carcinoma postoperatively is due to locally unresected tumor, lymphatic permeation by tumor, or intraoperative implantation of viable shed cancer cells. One hundred eighty-five patients with colorectal carcinoma underwent resection for cure. Of these patients, 40 received diluted formalin intraluminally for prevention of local recurrence, and the remainder received no cancericidal agent. Distribution by tumor size and stage was similar in both groups. Local recurrence occurred in 2.6 percent of formalin-treated patients and 14.3 percent of untreated patients. The difference in recurrence rates was significant (p less than 0.05). No significant difference between the two groups was present in the actuarial survival curves. The 5-year survival rate was 66.6 percent in the formalin-treated group and 50.5 percent in the control group. No suture line recurrences were observed in the treated group. Our results indicate that intraluminal fixation of cancer cells before opening the bowel is an effective method of reducing local recurrence after resection of colorectal cancer.