Table 1. Amsterdam II criteria (5) and Bethesda criteria (6).

Amsterdam II criteria (all criteria must be met)

Three or more relatives with histologically confirmed colorectal cancer or cancer of the endometrium, small bowel, ureter, or renal pelvis, one affected relative being first-degree relative of the other two; FAP should be excluded

Two or more successive generations are affected

At least one relative was diagnosed before the age of 50 years

Revised Bethesda guidelines (one or more of the following criteria must be met)

Colorectal cancer before the age of 50 years

Synchronous or metachronous colorectal cancer or other HNPCC-related tumors, regardless of age

Colorectal cancer with MSI-H morphology before the age of 60 years

Colorectal cancer (regardless of age) and a first-degree relative with colorectal cancer or an HNPCC-related tumor before the age of 50 years

Colorectal cancer (regardless of age) and two or more first- or second-degree relatives diagnosed with colorectal cancer or an HNPCC-related tumor (regardless of age)

FAP, familial adenomatous polyposis; MSI, microsatellite instability.