Genetic counselling for breast cancer

Mention the word genetics, and I have observed two types of reactions, poles apart from each other – either fascination and an eagerness to learn more about our inheritance; or a glazed look that films over the eyes with the knowledge that they are going to get lost in the medical jargon and concepts that are difficult to comprehend.

That is where the role of a genetic counsellor fits in. Genetic counsellors are medically trained healthcare professionals, registered with the Health Professionals Council, whose purpose is to translate genetic and other medical information into something that is understandable and meaningful. This enables a person to make informed choices in how to deal with a part of their medical future. Finding out genetic information about you, your partner, your parents or your children may have life-changing effects.

There are so many genes associated with the formation of breast cancer; the most common are BRCA1 and BRCA2. Over 15 genes have already been described as being associated with breast cancer formation and it is not practical, or financially viable to test for all of these. Genetic counselling is an individualised process, and a genetic counsellor will guide each individual through their path of what testing is suitable for them personally.

All cancers are genetic, but not all cancers are hereditary.

We have all heard about Angelina Jolie who has publicised her BRCA1 status in the hope of getting women talking about breast cancer, and encouraging them to be tested. The reality is that only 5-10% of breast cancers are inherited. That means that many people affected with breast cancer will not gain any useful information by having genetic testing for breast cancer. As previously mentioned, there are so many genes that may be involved in the development of breast cancer, it is not practical to test for all of them.

The process of genetic counselling for breast cancers includes a pre-test counselling session. The following aspects are usually covered:

  • Family history
  • Risk calculation
  • Genetic education 
  • Realities of genetic testing
  • Exploring patient perceptions
  • Discussing expectations about the testing and test results
  • Interpretation of information 

Blood for genetic testing may be taken after this first counselling session. Depending on the testing being conducted, the results will take several weeks to months before they are complete. This can be a time filled with much anxiety.

The results of genetic testing are revealed in a post-test counselling session. This is important to help people understand what the genetic results are, what they mean to the individual, and what further action or steps may be offered to them. The genetic counsellor helps people filter through the plethora of information and assists the individual to make choices that are most appropriate for them. Autonomy is a key factor in genetic counselling; it is important that an individual makes their own choices and is then supported in those choices by their healthcare professionals.

Predictive genetic testing vs. Diagnostic genetic testing

When breast and/or ovarian cancer have been diagnosed in a family, it may be possible for other family members to have predictive genetic testing performed. This gives them a chance to do something pro-active about their breast cancer risk.

The process of predictive testing involves thinking about your breast cancer risk, before anything has developed. This can be a complex process for some, and difficult, as it involves thinking about what might happen. A genetic counsellor is trained to guide individuals through this process. Predictive genetic testing for breast cancers is not offered to individuals under the age of 18 years, as they are not usually at risk for the development of breast cancer.

Information to gather before you see a genetic counsellor

Find out about the cancer diagnoses in your family. Ask the questions: Who is affected? Which cancer was their primary cancer? What was their age at diagnosis? If anyone has passed away, at what age did they pass away?

All this information helps in guiding a genetic counsellor in assessing which genetic testing is most appropriate. It is important that evey assessment is individualised. Members of the same family may have similar risks, but depending on the relationships and who in the family is affected, their risks may be different.

When should you see a genetic counsellor?

There is an increased probability of finding an inherited cancer in your family when there are:

  • Four or more cases of breast cancer diagnosed <60years
  • Three cases of breast cancer diagnosed <50years
  • Two cases of breast cancer and one of ovarian cancer
  • Male breast cancer diagnosed
  • You come from a high risk ethnic group (eg. Ashkenazi Jewish or Afrikaner background)
  • You have a personal history of breast cancer diagnosed at a young age
  • You have a diagnosis of bilateral breast cancer
  • A woman in your family has both ovarian and breast cancer
Who to contact?

There are very few registered genetic counsellors in the country – only 22 in total. However, most are based in the urban areas of Johannesburg, Pretoria, Durban, Cape Town and Bloemfontein. Ask your doctor for a referral to your closest centre.

Written by Sarah Walters

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