Gene: 𝘾𝘿𝙃𝟭
Cancer Risks and Management per NCCN Genetic/Familial High-Risk Assessment: Breast/Ovarian/Pancreatic Version 1.2021 and Gastric Version 3.2020:
𝗪𝗼𝗺𝗲𝗻:
Breast cancer risk: Elevated at 55% – Recommend annual mammogram starting at age 30; consider breast MRI with contrast starting at age 30.
𝗠𝗲𝗻 𝗮𝗻𝗱 𝗪𝗼𝗺𝗲𝗻:
Stomach cancer risk: Elevated at 83% for women, and 67% for men – Recommend prophylactic total gastrectomy (removal of stomach) between ages 18 and 40, and may be considered prior to age 18 for certain individuals with family history of stomach cancer before age 25; For those who elect not to undergo prophylactic gastrectomy, recommend upper endoscopy with multiple random biopsies every 6-12 months.
Inheritance: Autosomal dominant, thus parents, full siblings, and children have a 50% risk for the gene mutation.
Family Testing: At-risk family members should consider genetic counseling and genetic testing. For adult-onset conditions, recommend waiting to perform genetic testing on minors until they are at least 18 years old, unless family history of stomach cancer diagnosed before age 25.
Reproductive Considerations: Option for preimplantation genetic diagnosis (PGD) may be available to ensure future generations do not inherit the known gene mutation. PGD is a procedure available for certain gene mutations to screen the embryo prior to achievement of pregnancy.
Check out the full management guidelines by creating a FREE account at https://www.nccn.org/professionals/physician_gls/pdf/gastric.pdf and https://www.nccn.org/professionals/physician_gls/pdf/genetics_bop.pdf