Updating Genetic Testing – when and why you should consider retesting

24 Aug 2021

Tanya Dwarte is a Clinical Research Coordinator at one of Australia’s most respected medical research institutes, the Garvan InstituteThe Pink Hope team reached out to Tanya for her expert opinion on when and why an individual or family should recontact a genetics service for updated information. 

When should someone reconnect with their genetics service? 
Most genetics services advise that individuals and families should check back in with the service if or when: 

1. There is a new cancer diagnosis in the family or other changes to the family history (e.g. births, deaths in the family)

2. They are approaching the age when screening is recommended to begin, or other risk management needs to be considered (e.g. risk-reducing bilateral salpingo-oophorectomy) 

3. They are planning a family and have questions about their reproductive options

4. Their contact details have changed, and they would like to maintain contact with a service (e.g. receive a newsletter, are interested in recontact should new information become available) 

When to consider updated genetic testing. 
We know that some families had genetic testing over 10-15 years ago and our technologies and knowledge of cancer predisposition genes have changed considerably since then. Individuals who previously had uninformative or inconclusive testing may wish to arrange a genetics review to see if there is any further testing recommended for them.  

This would be assessed based on the individual family history and situation, but in many circumstances, people who were tested 10-15 years ago would likely have only had testing for the BRCA1 and BRCA2 genes. As there are several newly discovered high and moderate risk breast cancer predisposition genes, it may be appropriate for these individuals to have updated genetic testing.  

 It is likely that individuals who had testing in the last 5 years have already had testing for some of these more recently discovered genes. Again, depending on the genetic testing they have already had and their family history, they may have been provided with advice to check-in in 3-5 years to see if any additional information becomes available.  

What can you tell us about polygenic risk? 
Unfortunately, there are still many families where we can't yet find an explanation for their family history of cancer. We know an exciting area of research into breast cancer predisposition is a polygenic risk. This is the impact of having many genes that individually have a small influence on breast cancer risk, but if a person inherits a certain combination of these low-risk genes they can combine to contribute to overall increased cancer risk. This is not something we can currently test for in the clinic, but current evidence suggests that this might be possible in the next 5 years.   

Final words 
Ultimately, families are encouraged to maintain contact with their genetics service by checking-in every 5 years or so or if they have any questions about one of the key check-in times I listed above. 

If you would like to know more about your risk of breast and ovarian cancer, you can take our Know Your Risk questionnaire here, and you can access our library of resources that will help you assess, understand and reduce your risk here. 

Do you have a question that you would like answered about genetics? Email us by clicking here.