Malignant tumors were induced in the stomachs of rats by 3-methylcholanthrene (3-MC) injections. Invasion of surgically arranged adjacent jejunum occurred in 18% from group 1 when the jejunum was implanted into the stomach, and in 4.3% from group 2 when the injected stomach segment had been implanted into the jejunum. In controls, where a simple gastric incision was made and closed, invasion across the suture line occurred in 50% from group 3. This experience parallels the clinically recognized resistance of human small intestine to malignant tumors.
Yamakawa T, Patin CS, Morgenstern L. Small Intestinal Resistance to Experimental Gastric Cancer. Arch Surg. 1972;105(1):105-108. doi:10.1001/archsurg.1972.04180070103022