Question: How do genes influence colon cancer risk?
For most people, the impact of genes is minimal. About 75% of colon cancer occurs in people with no (or very little) family history of the disease. However, the other 25% of cases are attributed to two types of colon cancers: familial and hereditary.
Answer: Familial colon cancer accounts for about 20% of cases and hereditary colon cancer accounts for the remaining five percent. Both are caused by genetic mutations passed from one generation to the next.
Familial Colon Cancer
Presence of the mutated genes that cause familial colon cancer increases the risk of developing the disease. The risk is almost three times greater when two immediate family members have been diagnosed with colon cancer. It's ten times greater when three immediate family members have had colon cancer. Parents, siblings, and children are considered immediate family members with regard to colon cancer risk.Hereditary Colon Cancer
People who carry genetic mutations linked to hereditary colorectal cancer are the most likely to develop the disease. Individuals who carry the mutation that causes familial adenomatous polyposis (FAP) have almost a 100% chance of developing colon cancer by age 45.Someone who carries mutations linked to hereditary non-polyposis colorectal cancer (HNPCC) can have up to an 80% risk of developing the disease. FAP and HNPCC are the most common types of hereditary colorectal cancer.
To learn about other causes of colon cancer, please read 15 Causes of Colon Cancer.
Related Research:
- Smoking Increases Risk for Carriers of the HNPCC Gene
- HNPCC Gene Settles in America
- BRCA Mutations May Not Increase Colon Cancer Risk
- Bloom Syndrome Increases Colorectal Cancer Risk
- Insight into the Origin of Colon Cancer
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