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. Author manuscript; available in PMC: 2010 Mar 29.
Published in final edited form as: Clin Genet. 2009 Jul;76(1):1–18. doi: 10.1111/j.1399-0004.2009.01230.x

Table 3.

Amsterdam Criteria I and II (AC-I and II) and Bethesda Guidelines

AC-I (24)

  • At least three relatives with histologically verified colorectal cancer:

    1. One is a first-degree relative of the other two;

    2. At least two successive generations affected;

    3. At least one of the relatives with colorectal cancer diagnosed at <50 years of age;

    4. Familial adenomatous polyposis (FAP) has been excluded.

AC-II (25)

  • 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 tumors)]:

    1. One is a first-degree relative of the other two;

    2. At least two successive generations affected;

    3. At least one of the syndrome-associated cancers should be diagnosed at <50 years of age;

    4. FAP should be excluded in any colorectal cancer cases;

    5. Tumors should be verified whenever possible.

Bethesda Guidelines for testing of colorectal tumors for microsatellite instability (MSI) (145)

  1. Colorectal cancer diagnosed in a patient who is <50 years of age.

  2. Presence of synchronous or metachronous colorectal, or other syndrome-associated tumorsa regardless of age.

  3. Colorectal cancer with microsatellite instability-high (MSI-H)b histologyc diagnosed in a patient who is <60 years of aged.

  4. Colorectal cancer or syndrome-associated tumora diagnosed under age 50 years in at least one first-degree relativee.

  5. Colorectal cancer or syndrome-associated tumora diagnosed at any age in two first- or second-degree relativese.

a

Syndrome-associated tumors include colorectal, endometrial, stomach, ovarian, pancreas, ureter or renal pelvis, biliary tract, and brain (usually glioblastoma as seen in Turcot syndrome) tumors, sebaceous gland adenomas and keratoacanthomas in Muir–Torre syndrome, and carcinoma of the small bowel.

b

MSI-H = microsatellite instability-high in tumors refers to changes in two or more of the five National Cancer Institute-recommended panels of microsatellite markers.

c

Presence of tumor infiltrating lymphocytes, Crohn disease-like lymphocytic reaction, mucinous/signet-ring differentiation, or medullary growth pattern.

d

There was no consensus among the Workshop participants on whether to include the age criteria in guideline 3 above; participants voted to keep <60 years of age in the guidelines.

e

Criteria 4 and 5 have been reworded to clarify the Revised Bethesda Guidelines.