Genetic Testing for Cancer

Genetic testing can help you understand the risk of developing cancer or passing it on to your children. It is a personal decision you should make in collaboration with your family, doctor, and genetic counsellor.

Genetic cancer testing looks at the DNA code for a specific gene or genes. It provides information about the gene(s) which are analysed and is usually performed on a blood or saliva sample. Results are normally available in 3-6 weeks. There are several different types of testing available including:

Diagnostic testing

This attempts to find the possible cause of cancer within the family and is best performed on someone who has had cancer. There are 3 possible results:

1. The test is normal. This means no disease causing mutation is found. There may still be an increased risk of cancer and increased screening may still be recommended.

2. A known cancer causing mutation is found. Cancer screening can be targeted and relatives can have testing for this mutation.

3. A variant of unknown significance is found. This means the laboratory has found a change in the gene that they cannot interpret i.e. the result is inconclusive. Cancer screening will be based on the family history.

Predictive testing

When the familial mutation is known it is possible to give relatives a definitive answer:

1. If the mutation is not present there is no increased risk of cancer.

2. If the mutation is found the indidivual has an increased risk of cancer. Increased cancer screening and risk reducing options may be helpful.

Reasons to consider genetic testing for cancer:

To help make medical decisions, such as lowering your risk through surgery, medication, or lifestyle changes. You may also receive cancer screening more often.

Relieve anxiety, especially if you know your family has a history of cancer from a specific gene mutation.

Ease uncertainty about whether you have a specific gene mutation linked to cancer

Provide information to your family about you and your children’s chance of having a specific gene mutation.

Are GeneHealth UK genetic cancer tests the same as the ones offered by the NHS?

BRCA1 & BRCA2 genetic cancer tests are the same tests as those offered through the NHS. BowelGene, ProstateGene, OvarianGene and BreastGene are more comprehensive and not yet available through the NHS. Your genetic counsellor can provide you with more information.