Literature Review from the year 2017 in the subject Medicine - Pathology, Egerton University, language: English, abstract: From a pathological perspective, cancers occur due to the failure of the immune system. It is evident that the immune system plays key roles in preventing cancer through regulating cell population in the body. Ordinarily, the bodys immune system is usually involved in some cellular processes, especially in the cell cycle in which it destroys old or defective cells through programmed cell death, a process commonly known as apoptosis. In the context of cancer, this process is usually impaired, thus damaged or defective cells are not destroyed by the immune system. In addition, the impairment of the immune systems activity affects cellular homeostasis processes including irregular cell division. These factors are responsible for tumor growth and progression of cancer. Gastric cancer affects the digestive system, primarily the stomach. Anatomically, the stomach occupies the region from the esophageal junction to the duodenum. Therefore, aim of this research is to carry out a comprehensive review of gastric cancer, also known as stomach cancer.