STOMACH CANCER Stomach (gastric) cancer is cancer that starts in the cells lining in the stomach. The stomach is an organ on the left side of the upper abdomen that digests food. Let's change the world together Share this content Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window