Table 3.
Contrasting two types of families that fulfill the pedigree Amsterdam-I Criteria (adapted from Familial Colorectal Cancer Type X In: Genetics of Colorectal Cancer, Chapter 8.2. JD Potter and NMLindor, Eds. Springer, Publishers. In press, 2008).
| Lynch Syndrome | Familial Colorectal Cancer Type X | |
|---|---|---|
|
| ||
| Colorectal | ||
|
| ||
| Cancer risk | very high | modestly increased |
| Age of onset | ~ 45 years average | 50s–60s |
| Usual location | proximal colon | distal colon |
| Polyps | Few | More |
| Malignant transformation | Rapid | Less rapid |
|
| ||
| Other cancers | ||
|
| ||
| Endometrial risk | Very high risk | Risk not significantly increased |
| Other cancer sites | Many others | None known |
| Germline MMR genes | Mutations found | No mutations found |
| CRC tumor testing | Microsatellite instability | No microsatellite instability (by definition) |
| CRC Tumor staining | Loss of MMR protein expression | Normal expression |
CRC = colorectal cancer
MMR = mismatch repair