All 5 criteria must be met to classify as Amsterdam II positive. Criteria met = offer germline MMR gene panel testing. Low sensitivity (~60%) — universal MMR-IHC of CRC tumours is supplementary.
≥ 3 relatives with Lynch-associated cancer
CRC, endometrial, small bowel, ureter, or renal pelvis — one must be a 1st-degree relative of the other two
≥ 2 successive generations affected
≥ 1 patient diagnosed before age 50
FAP (Familial Adenomatous Polyposis) excluded in CRC cases
No evidence of FAP phenotype in colorectal cancer cases
Tumours verified by pathology
Not self-report; histopathology confirmation required
Verified
Last Review: 2026
Last Comprehensive Review: 2026