Table 1.
Hereditary Cancer Syndromes With Increased Risks of Gastric Cancer
| Syndrome | Associated gene(s) | Lifetime gastric cancer risk | Other associated cancers | Nonmalignant phenotypic features |
|---|---|---|---|---|
| HDGC | CDH1; possibly CTNNA1, MAP3K6, and others | 67%–70% (males), 56%–83% (females) | Lobular breast carcinoma | Cleft lip/palate in some families |
| FAP | APC | <1%a | Colorectal duodenal/ampullary, thyroid, desmoid tumors, hepatoblastoma, medulloblastoma | Colorectal (and duodenal and gastric) adenomas, gastric fundic gland polyps, osteomas, CHRPE, supernumerary teeth |
| GAPPS | APC (promoter 1B region) | Undefined, but likely higher than FAP | None known | Fundic gland polyps of the proximal stomach |
| Lynch syndrome | MLH1, MSH2, MSH6, PMS2, EPCAM | <1% to 13%a | Colorectal, endometrial, ovarian, urothelial, pancreatic, small-bowel, and hepatobiliary | Cutaneous sebaceous adenomas and keratoacanthomas |
| Li–Fraumeni syndrome | TP53 | ∼5%a | Breast, sarcomas, lung, adrenocortical, brain (choroid plexus), leukemias, colorectal, many others | None |
| Peutz–Jeghers syndrome | STK11 | ∼29% | Breast, pancreatic, lung, colorectal, small intestine, ovaries, testes | Hyperpigmentation of oral/genital mucosa, lips, fingers; hamartomatous polyps of GI tract, especially small bowel |
| Juvenile polyposis syndrome | BMPR1A, SMAD4 | ∼21% | Colorectal and duodenal cancers | Juvenile polyps of the GI tract |
CHRPE, congenital hypertrophy of the retinal pigment epithelium; GI, gastrointestinal.
a
Risks may be higher in Asian patients.