Identifying Individuals and Families at Risk

Clinical Criteria for Diagnosis

LS may be indicated where the family history of cancer meets either the Amsterdam II Criteria or Bethesda Criteria.

Family Cancer History

A cancer family history is an important diagnostic tool.

Lynch Syndrome Australia provides a simple template for patients to use to assist in identifying a relevant family history.


Using these criteria may fail to identify some families with Lynch syndrome; particularly where family size is small or where knowledge of family cancer history is incomplete (e.g., where family members are unknown, or family members are reluctant to discuss details of this sort). It is important to consider these limitations and take a conservative approach to assessing a family history.

A diagnosis of LS is a life changing experience for a patient and they may take time to adjust to the diagnosis. Consider counselling or referral for ongoing support.

Next: Genetic Testing

Amsterdam II criteria

The patient has:

  • At least 3 relatives with cancers listed above , one of whom is a first degree relative of the other two, and
  • At least 2 successive generations are affected, and
  • At least 1 affected relative had a cancer diagnosis under age 50.

(Updated) Bethesda criteria

The patient has:

  • A Uterine cancer under age 50, or
  • A Colorectal cancer (CRC) under age 50, or
  • Synchronous or metachronous CRC (or other Lynch cancer) regardless of age, or
  • A CRC with MSI‐H negative histology under age 60, or
  • A CRC and one first degree relative also has/had a CRC (or other Lynch cancer) with one of the cancers being diagnosed under age 50, or
  • A CRC with two or more first or second degree relatives with CRC (or other Lynch cancers) regardless of age.