What are genes and why am I being offered a genetic test?
We have given you this information leaflet because you have been diagnosed with or are currently being investigated for ovarian, peritoneal or fallopian tube cancer. We would like to offer you a genetic test to identify any faulty genes that may have contributed to you developing this type of cancer. This can help to plan the best treatment for you. This test is done on the sample of the tumour (or biopsy) that has or will be taken to confirm your diagnosis or as part of your treatment. If the tissue sample does not show a cancer or a cancer of a different type then genetic testing will not be performed.
Genes make up our DNA which is found in almost every cell in our body. They act as an instruction manual which contains information that enables our bodies to grow and function correctly. Genes are inherited from our parents. You receive half from each parent and any biological children you have will inherit half of their genes from you.
Cancer is a common condition and some cancers start due to an inherited faulty gene which can be passed down in families (this is called hereditary cancer and is tested for separately with a blood test). Most cancers start due to cell changes that happen as we get older.
What are BRCA1 and BRCA2 genes (BReast CAncer genes)
Everyone has two copies of the BRCA1 and BRCA2 genes (BReast CAncer genes), one set inherited from your mother and one from your father. These genes are known as tumour suppressor genes because they are normally protective against cancer by helping to repair breaks in DNA that can lead to cancer. Changes in these genes can occur randomly during our lifetime and along with other factors can increase the risk of developing breast and, or ovarian cancer.
Most of the time cancer causing genetic variants is only found in cancer cells (the tumour). These are called somatic variants and are not found in normal healthy cells of a person who has cancer. The genetic test we are offering you looks for somatic variants in the BRCA1 and BRCA2 genes in your tumour.
We would also test for homologous recombination deficiency (HRD). HRD means that cells cannot correctly be repaired when damaged, and cells with HRD can become cancerous. There are many reasons that can cause a tumour to be HRD positive, one of which is having a BRCA variant.
You are being offered this test because genetic testing of your tumour will help your specialist cancer team to plan your treatment.
How is the test done?
Following a biopsy or surgery a pathologist will send a sample of the tumour to a genetic laboratory for testing. This type of test (a tumour test) will identify if your tumour has a BRCA variant and, or has HRD. This type of genetic testing on tumour samples will not tell you or your family members if there is a risk that the cancer could be inherited. If ovarian cancer is diagnosed further testing with a blood test (called germline testing) will be discussed with you. This type of test will tell you if the cancer can run in families (hereditary cancer).
How will I get the results of my test?
The results of the tissue testing will take several weeks. The results will be sent to your consultant who will contact you.
The following websites have more information about BRCA and HRD testing
www.targetovariancancer.org.uk
https://eveappeal.org.uk/wp-content/uploads/2021/01/01_Ask-Eve-Booklet-Mobile-22.12.20.pdf