Is Stomach Cancer Hereditary?

Stomach cancer is not classified as a hereditary disease, although it can sometimes appear to cluster within families. This phenomenon is often attributed to shared environmental factors and lifestyle habits rather than direct genetic transmission. For example, children and their parents or grandparents may live together or share similar dietary patterns, hygiene practices, and exposure to certain risk factors.

One of the key contributors to this familial pattern is the transmission of Helicobacter pylori infection. If a parent is infected with H. pylori, a known risk factor for stomach cancer, it's possible for children in the same household to become infected as well. Additionally, families living in areas with limited access to clean water and fresh produce—such as vegetables and fruits—may experience similar dietary deficiencies, further increasing the risk across generations.

While stomach cancer can occur in multiple family members, this does not mean it is passed down genetically like conditions such as hemophilia, which follows a clear autosomal dominant inheritance pattern. Current research has not identified a specific chromosome or gene directly linked to the development of stomach cancer. Therefore, while a family history of stomach cancer may increase an individual's risk, it is not considered a strictly inherited disease.