 The purpose of this study is to establish a gastric cancer registry. A registry is a database of information. With the registry, we can learn more about the genetic causes of gastric cancer in order to develop better methods of early diagnosis, prevention, and treatment of gastric cancers. As part of this study, you will be asked to join a registry of families who are affected with various forms of gastric cancer. These registries are important because they may help physicians better manage gastric cancer now and in the future. Participating in the Early Onset and Familial Gastric Cancer Registry can also be educational for families, since it will provide important information to patients, families, and physicians. All of this will help to further our understanding of genetic causes of gastric cancer and eventually, help determine better ways to diagnose, treat, and survey patients with gastric cancer and people who may have a higher risk for gastric cancer. 