Table 3.

Comparison of hereditary cancer syndromes

Condition	Genetic pathology	Lifetime risk of gastric cancer	Histological subtype	Other clinical features
Hereditary diffuse gastric cancer	CDH1 germline and other gene mutations	80%	Diffuse	Association with lobular breast cancer and cleft-lip malformations
Lynch syndrome	Mutations in mismatch repair genes	4.8% in MLH1 carrier 9% in MLH2 carrier[58]	Mainly intestinal-type	Lifetime risk of colon cancer 31%-38%, endometrial cancer 34% and ovarian cancer 20%[59]
Familial adenomatous polyposis	APC germline mutations	Population risk[60]	No data	Malignant extraintestinal tumours rare < 3% (thyroid, pancreas, medulloblastoma)[61]
Li-Fraumeni syndrome	TP53 mutations	14.9%[62]	No predominant subtype	Associated with wide range of early-onset cancers. Includes haematological and solid organ cancers: sarcomas, breast, brain, adrenal and lung cancers
Peutz-Jegher’s syndrome	STK11 mutations	29%[63]	No data	Characteristic mucocutaneous pigmentation commonly around mouth and nose High cumulative lifetime risk of any cancer (85%), most commonly colorectal (50%)[58]
Juvenile polyposis syndrome	SMAD4 or BMPR1A mutations	121%[64]	No data	Also at increased

¹Frequency based on cross-sectional sample rather than lifetime risk from cohort study.