Regardless, the Amsterdam criteria
fail to identify approximately 50% of cases, and Bethesda guidelines fail to identify at least 30% of cases , which has led to increased support for the universal application of the polymerase chain reaction (for detection of MSI-high tumors) and/or IHC testing to all CRC specimens .
This patient's family history fulfilled Amsterdam criteria
for Lynch syndrome with more than three family members with CRC in two consecutive generations and more than one family member diagnosed earlier than the age of 50 years.
All individuals and families that fulfil the Amsterdam Criteria
should be referred for colonoscopic surveillance as well as further laboratory testing to diagnose or exclude Lynch syndrome.
The Amsterdam criteria
were proposed in 1990  and revised in 1997 to identify families at risk of HNPCC.
In clinic, it is diagnosed by Amsterdam criteria
I:5 (1) three or more relatives with histologically confirmed colorectal cancer, one of whom is the first-degree to the other two; (2) colorectal cancer affecting at least two generations; and (3) one or more colorectal cancer cases diagnosed before the age of 50.