DR Medhat MRCP

Inherited (familial) colorectal cancer :
1) Hereditary non-polyposis colorectal carcinoma (HNPCC ) : 5%
- An autosomal dominant condition
- Is the most common form of inherited colon cancer.
- Around 90% of patients develop cancers, often of the proximal colon,
which are often poorly differentiated and highly aggressive.
- Currently four gene mutations have been identified (including in the MLH1
,MSH2 & APC genes).
- The Amsterdam criteria are sometimes used to aid diagnosis
At least 3 family members with colon cancer.
The cases span at least two generations .
At least one case diagnosed before the age of 50 years .
2) Familial adenomatous polyposis (FAP) :