Genetic testing is an important way that people with a diagnosis of cancer can understand the role of genetics in their diagnosis. Certain types of cancer such as breast, ovarian, pancreatic, prostate, bowel and endometrial cancers may be caused by genetic variants that increase the risk of developing these cancers. For example, women who have inherited a variant form of the BRCA1 or BRCA2 gene have a lifetime risk of developing breast cancer of around 70%, compared to the 12% risk faced by women in the general population.
Genetic testing involves the testing of a person’s genes to identify if they are at a higher risk of certain cancers. The process generally begins with sequencing the DNA of a person who has been diagnosed with cancer to look for genetic variants or ‘spelling mistakes’. If a gene variant is found which explains the person’s diagnosis of cancer, their relatives can have genetic testing to see if they have inherited it also. For people who have not yet had a cancer this is called predictive testing, because it can predict future cancer risk, enabling a person to take preventative action, such as undergoing special cancer screening tests, or having preventative surgery.
Before you undergo genetic testing, you will need to meet with a specialist healthcare professional known as a genetic counsellor. A doctor’s referral is not required to access genetic counselling services and referrals can be made by patients, carers or healthcare professionals.