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Table 1 Revised Bethesda guidelines for testing colorectal tumors for microsatellite instability (MSI)

From: Germline deletions in the EPCAM gene as a cause of Lynch syndrome – literature review

1 Colorectal cancer diagnosed below 50 years of age.
2 Presence of synchronous, metachronous colorectal, or other Lynch syndrome-associated* tumors, regardless of age.
3 Colorectal cancer with high-MSI*, histology diagnosed in a patient who is less than 60 years of age.
4 Colorectal cancer diagnosed with one or more first-degree relatives with Lynch syndrome – associated tumors*, with one of the cancers being diagnosed under age 50 years.
5 Colorectal cancer diagnosed in two or more first or second degree relatives with Lynch syndrome-associated tumors* regardless of age
  1. *Lynch syndrome–associated tumors: tumors of the endometrium, small bowel, or urinary tract; high-MSI = high level microsatellite instability in tumors refers to changes in two or more of the five NCI-recommended panels of microsatellite markers.
  2. Revised Bethesda guidelines for hereditary nonpolyposis colorectal cancer [Lynch syndrome] and microsatellite instability (Umar A, Boland CR, Terdiman JP, et al. (2004).