The Bethesda Criteria

The Bethesda criteria were developed to identify colorectal cancer patients with possible Lynch syndrome (HNPCC), to be genetically studied and diagnosed. 

These are highly sensitive criteria, so able to identify a large percentage of patients with the Lynch mutation. 

If you fulfill the Bethesda criteria, the genetic study can start with an analysis of the tumor, either by  microsatellite instability  (MSI) testing, or genetic sequencing (process that identifies the precise order of the units that constitute the patients’ DNA, looking for genetic abnormalities/mutations)(MSI), ou avançar directamente para o teste genético por sequenciação genética.

_{Learn more about  genetic testing}

The Bethesda criteria – see if you present them

• A diagnosis of CRC* before the age of 50
• Multiple HNPCC**-associated tumors – whether synchronous*** or metachronous*** CRC, or other types of tumors associated with the syndrome – developed at any age
• Individuals with CRC positive for MSI (MSI+)****, diagnosed before the age of 60
• Individual with CRC and a first-degree relative with an HNPCC-associated tumor, one of them diagnosed before the age of 50
• Individual diagnosed with CRC, who has two or more 1st or 2nd-degree relatives with HNPCC-associated tumors

^{*CRC - colorectal cancer ** HNPCC is a hereditary cancer syndrome - when an inherited mutation predisposes the individual to develop more than one type of cancer. In HNPCC case these include colorectal, endometrium, small intestine and urothelial (urinary system) cancer .
** Metachronous cancers are new primary tumors not connected with previous cancers of the patients, while Synchronous cancers are also multiple primary tumors in a patient but developing at the same time.
**** MSI – microsatellite instability} 

Briefly, criteria to identify CRC patients who might have Lynch syndrome:

• Diagnosed early in life
• With one or two cancers, diagnosed simultaneously or sequentially, at an early age
• With an MSI+ tumor 
• Several disease cases in a family, even if they do not fulfill the Amsterdam criteria