Hereditary Colon Cancer

What about genetic testing?

Researchers around the world have been able to find some of the genes that are involved in hereditary colon cancer. For some families, it may be possible to find out if one of these genes is being passed on through the family. If such a gene is found, genetic testing can be offered to other relatives, in order to identify which family members have an increased risk of cancer, and which family members do not. Relatives with the gene can then continue their screening program, while relatives who did not inherit the gene can be reassured that their chance of developing cancer is the same as the general population.

It is important to know that genetic testing for colon cancer is a new and somewhat complicated test. It is still considered to be research, and for this reason, bowel screening is still the best way to deal with the increased risk of cancer in a family.

Before any testing can be done, a relative who has survived colon cancer will meet with a genetic counsellor to explain how the test works, and what the results could mean. It is important to know that genetic testing for colon cancer is a new and somewhat complicated test currently being offered to all Ontario residents who have been identified at high-risk for hereditary colon cancer. (see "How can you tell if a family has hereditary colon cancer?"). However, bowel screening is still the best way to deal with the increased risk of cancer in a family.

Genes are the basic units of heredity that determine how our bodies grow and develop. Each of us inherits thousands of genes from our parents. Each gene has a specific job that it does within the body- some genes control our eye or hair colour, while others tell us what blood type we have. The genes that cause hereditary colon cancer have to do with the normal growth of cells in the body, like the cells that line the colon. A person with a gene for hereditary colon cancer can pass it on to their children. Each child has a 50% chance of inheriting the gene and a 50% chance of not inheriting it.

Having an inherited cancer gene is often called having an "inherited predisposition" to cancer. This simply means that someone has inherited a gene that makes it more likely that they will develop cancer.

It is important to know that having a cancer gene does not guarantee that a person will develop cancer. This is how cancer can appear to "skip a generation" in a family tree. In the same way, not having a cancer gene does not guarantee that a person will not get cancer — it just means that they have the same chance as anyone else.

Hereditary Colon Cancer

What about genetic testing?

Researchers around the world have been able to find some of the genes that are involved in hereditary colon cancer. For some families, it may be possible to find out if one of these genes is being passed on through the family. If such a gene is found, genetic testing can be offered to other relatives, in order to identify which family members have an increased risk of cancer, and which family members do not. Relatives with the gene can then continue their screening program, while relatives who did not inherit the gene can be reassured that their chance of developing cancer is the same as the general population.

It is important to know that genetic testing for colon cancer is a new and somewhat complicated test. It is still considered to be research, and for this reason, bowel screening is still the best way to deal with the increased risk of cancer in a family.

Before any testing can be done, a relative who has survived colon cancer will meet with a genetic counsellor to explain how the test works, and what the results could mean. It is important to know that genetic testing for colon cancer is a new and somewhat complicated test currently being offered to all Ontario residents who have been identified at high-risk for hereditary colon cancer. (see "How can you tell if a family has hereditary colon cancer?"). However, bowel screening is still the best way to deal with the increased risk of cancer in a family.

Genes are the basic units of heredity that determine how our bodies grow and develop. Each of us inherits thousands of genes from our parents. Each gene has a specific job that it does within the body- some genes control our eye or hair colour, while others tell us what blood type we have. The genes that cause hereditary colon cancer have to do with the normal growth of cells in the body, like the cells that line the colon. A person with a gene for hereditary colon cancer can pass it on to their children. Each child has a 50% chance of inheriting the gene and a 50% chance of not inheriting it.

Having an inherited cancer gene is often called having an "inherited predisposition" to cancer. This simply means that someone has inherited a gene that makes it more likely that they will develop cancer.

It is important to know that having a cancer gene does not guarantee that a person will develop cancer. This is how cancer can appear to "skip a generation" in a family tree. In the same way, not having a cancer gene does not guarantee that a person will not get cancer — it just means that they have the same chance as anyone else.