Is Stomach cancer hereditary?

While most cases of stomach cancer are sporadic and caused by environmental factors like H. pylori infection or diet, approximately 5% to 10% of cases are considered hereditary. In these instances, stomach cancer arises due to inherited gene mutations that significantly increase an individual's lifetime risk of developing the disease.

Is stomach cancer hereditary or genetic?

There is an important distinction: all cancers are genetic because they result from mutations in DNA, but only a small fraction are hereditary (passed from parent to child). Most stomach cancer develops from somatic mutations—changes that occur in cells during a person's lifetime. Hereditary stomach cancer syndromes, such as Hereditary Diffuse Gastric Cancer (HDGC), are caused by germline mutations present in every cell of the body from birth.

What are the known hereditary syndromes?

Several specific syndromes are linked to an increased risk of stomach cancer. These conditions typically follow an autosomal dominant inheritance pattern, meaning a child of an affected parent has a 50% chance of inheriting the mutation. Key syndromes include:

• Hereditary Diffuse Gastric Cancer (HDGC): Primarily caused by mutations in the CDH1 gene.


• Lynch Syndrome: Increases the risk of various cancers, including gastric.


• Li-Fraumeni Syndrome: Linked to TP53 gene mutations.


• Familial Adenomatous Polyposis (FAP): Associated with increased risk of gastric polyps and cancer.

When is genetic testing recommended?

Genetic testing is not standard for every patient diagnosed with stomach cancer. It is generally recommended if a patient meets specific clinical criteria, such as a strong family history of gastric cancer, early age of onset (typically under 50), or the diagnosis of diffuse-type gastric cancer. A clinical geneticist can help determine if testing is appropriate based on your specific family pedigree.

What is the role of genetic counseling?

Genetic counseling is vital for families affected by hereditary stomach cancer. Counselors provide risk assessment, explain the implications of testing results for family members, and discuss management strategies, such as prophylactic gastrectomy for high-risk individuals. While de novo (spontaneous) mutations can occur, most hereditary cases are inherited from a parent; therefore, cascade testing for at-risk relatives is a critical component of care.

Next steps

• Consult with a board-certified genetic counselor to review your personal and family medical history.


• Discuss with your oncologist whether your specific pathology profile warrants genetic testing.


• Connect with the 13 members of our DiseaseMaps.org community to share experiences and find support.


• Review resources from the NIH Genetic and Rare Diseases Information Center (GARD) for updated clinical guidelines.

Medical disclaimer: This information is for educational purposes only and should not replace professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Gastric Cancer.


• National Cancer Institute (NCI): Genetics of Gastric Cancer (PDQ).


• Orphanet: Hereditary Diffuse Gastric Cancer.


• OMIM (Online Mendelian Inheritance in Man): Gastric Cancer entry.