Implantation of colon cancer cells on intact and damaged colon mucosa and serosa: an experimental study in the rat.

The ability of malignant colon cancer cells to implant on intact and damaged colonic mucosa and serosa was tested in a series of experiments using male WAG rats. The mucosa was damaged in an "acute" way by multiple biopsies and in a "chronic" way by means of a chemically induced colitis. The creation of an anastomosis provoked both mucosal and serosal damages. CC531 colon cancer cells injected intraluminally as an enema implanted at the serosal side of an anastomosis without invading the mucosa in 66% of the rats. An intact colon mucosa is 100% resistant to the implantation of viable CC531 cells. In contrast, tumour growth was noticed in 100% of the rats when the malignant cells were sprayed over the intact colon serosa at laparotomy. Mucosal damage by biopsies in the presence of viable colon cancer cells resulted in mucosal implantation and intraluminal tumour growth in one out of thirty rats. No tumour growth was observed when the CC531 cells were instilled on one week old mucosal ulcerations resulting from a chemical induced colitis.