Table 1.

Breakdown of the Amsterdam Criteria I+II and Revised Bethesda Guidelines [11,12,13,14,15].

Amsterdam Criteria I At least three relatives with histologically verified colorectal cancer: One is a first-degree relative of the other two; At least two successive generations affected; At least one of the relatives with colorectal cancer diagnosed at <50 years of age; Familial adenomatous polyposis (FAP) has been excluded.

Amsterdam Criteria II At least three relatives with an hereditary nonpolyposis colorectal cancer (HNPCC)-associated cancer [colorectal cancer, endometrial, stomach, ovary, ureter/renal pelvis, brain, small bowel, hepatobiliary tract, and skin (sebaceous tumours)]: One is a first-degree relative of the other two; At least two successive generations affected; At least one of the syndrome-associated cancers should be diagnosed at <50 years of age; FAP should be excluded in any colorectal cancer cases; Tumors should be verified whenever possible.

Revised Bethesda Guidelines Colorectal tumors from individuals should be tested for MSI in the following situations: Colorectal cancer diagnosed in a patient who is <50 years of age. Presence of synchronous or metachronous colorectal, or other HNPCC-associated tumors regardless of age. Colorectal cancer with microsatellite instability-high (MSI-H) histology diagnosed in a patient who is <60 years of age. Colorectal cancer diagnosed in one or more first-degree relatives with an HNPCC-related tumor, with one of the cancers being diagnosed under age 50 years. Colorectal cancer diagnosed in two or more first- or second-degree relatives with HNPCC-related tumors, regardless of age.