What Is the Lifetime Risk of Stomach Cancer in CDH1 Mutation Carriers?

The Meaning and Importance of an Inherited CDH1 Mutation

CDH1, or the Cadherin 1 gene, helps cells bind to one another, supporting the healthy formation of tissues and organs. Located on chromosome 16, it plays a particularly critical role in cell adhesion. However, mutations in its structure can sometimes increase cancer risk. CDH1 mutations are strongly associated with certain cancers, particularly stomach and breast cancer.

Inherited mutations are genetic changes received from a person's parents and generally present from birth. Other changes in genetic material are acquired during life through environmental or other factors and are called somatic mutations.

Approximately 3% of all stomach cancers are estimated to arise from inherited mutations.

Stomach Cancer and CDH1: What Does the New Study Say About Risk?

Pathogenic or likely pathogenic changes in CDH1 are genetic changes that increase stomach cancer risk.

“Pathogenic” refers to genetic changes capable of causing disease, while “likely pathogenic” describes variants with this potential for which more data are needed.

Lower Risk Than Previously Estimated

On July 14, 2024, JAMA published a new study showing that stomach cancer risk in CDH1 mutation carriers may be lower than previous estimates , although it remains higher than in the general population.

Risk is particularly elevated in people with a family history of stomach cancer.

The new research estimated lifetime stomach cancer risk in men carrying CDH1 mutations at 10%, compared with 7% in women.

These figures can rise to 38% in people with a history of stomach cancer in three first-degree relatives.

Interestingly, 3% of all stomach cancers can be attributed to inherited factors, highlighting the importance of genetic testing and family history in cancer prevention.

Helicobacter Pylori and Inherited Factors: A Combination Increasing Stomach Cancer Risk

Helicobacter pylori (H. pylori) is a bacterium associated with stomach cancer and ulcers, estimated to infect about half the world's population. Stomach cancer risk has been observed to be highest when this infection combines with certain mutations in DNA repair genes. This combination makes cancer development even more likely in people carrying inherited risk factors. In particular, a study from Japan showed that H. pylori infection combined with pathogenic mutations in DNA repair genes substantially increased stomach cancer risk. These findings suggest that environmental factors contribute more to inherited stomach cancer risk than previously thought .

Early detection and effective treatment of H. pylori infection in people with inherited stomach cancer risk may therefore significantly reduce that risk.

CDH1 Mutation Testing and Its Importance

Genetic testing that identifies a CDH1 mutation may have important clinical implications for individuals and their families. Screening and prevention strategies recommended for carriers may increase the chance of early stomach cancer diagnosis.

If a person carries a CDH1 mutation and has multiple stomach cancer cases in their family, prophylactic total gastrectomy (removal of the entire stomach) may be recommended to reduce risk. Stomach health also needs close, continuous monitoring through regular endoscopy and biopsy .

Conclusion

CDH1 mutations carry stomach and breast cancer risks, which can be managed through early diagnosis and personalized treatment plans. Recent studies clarify these risks, allowing individuals and families to make more informed decisions. Every CDH1 mutation carrier should receive genetic counseling and regular screening support.