Oncogenetic tests may be carried out in a person with cancer, or in unaffected family members, after a familial mutation has been identified (using pre-symptomatic and predictive testing, and cascade screening of family members).

By undergoing oncogenetic tests before presenting with symptoms, you can find out if you are at risk of developing a disease.

For example, this type of testing can be useful in identifying your risk of breast and ovarian cancer, as well as some types of colorectal cancer. Risk reduction measures (preventive surgery) and close monitoring (MRI scanning) can be set up in the case of those with a genetic predisposition.

A recent concept relates to targeted therapy. People with a genetic predisposition (e.g. a predisposition to breast and ovarian cancer) have a favourable response to treatments that specifically target the faulty molecule (resulting from the mutation that causes predisposition; e.g. PARP inhibitors).

In the absence of hereditary predisposition, mutations qualifying for targeted therapy may be present exclusively in the tumour. For this reason, even in the absence of a familial predisposition, tumour analysis is increasingly important in predicting which individual may benefit from these innovative treatments.

The vast majority of cancers are not caused by a hereditary predisposition resulting from gene mutations, but are due to multifactorial predisposition. From hundreds to thousands of genetic variants dispersed in the genome contribute to risk – only in a subtle way individually – but the cumulative effect is comparable to that caused by a mutation. The tool that calculates this risk is called a polygenic risk score (PRS). The PRS for breast cancer is now available, and others will follow shortly.

Cancer screenings at Genesupport