Have a Conversation with Your Oncologist About Genetic Counselling

By Patricia Thangaraj

Breast cancer survivors who may not have had genetic testing previously or who may have had genetic testing done more than five years ago should have a talk with their oncologist and/or family doctor to get an updated assessment of their cancer risks and find out if there is a need for any new tests. And if yes, this physician can refer them for genetic counselling and testing.

This is according to Genetic Counsellor at the Bhalwani Familial Cancer Centre, Princess Margaret Cancer Centre, Brittney Gillies, who was answering a query during the Question and Answer segment of a webinar entitled “Breaking Ground: Moving Towards Universal Genetic Testing in Cancer” recently.

She said that the field of genetics is changing rapidly and they are always learning about new genes or getting new interpretations of previous results. Therefore, if patients wanted an updated status of their results, they can see if they can get referred to have this conversation.

“If someone did not have genetic testing previously or even if they did have testing done, you know five, 10 years ago. The field of genetics is rapidly changing all of the time and we’re learning about new genes or new interpretations of different types of results. So we typically recommend that patients be referred whether that’s five years in the future, three years in the future for an updated assessment to talk with a genetic counsellor about any previous results or if new testing would be indicated.”

Family History Collected From Both Sides Of The Family

Gillies also dispelled the myth that if a person has a family history of breast cancer on the paternal side of their family, then they are not eligible for genetic testing and/or that their risks of getting cancer would not be as high, stating that everyone inherits half of their genes from their maternal side and the other half from their paternal side. Therefore, genetic testing would involve collecting information from both sides of the family. 

“This is a common myth that a lot of people hear that if a family history of breast cancer is on the paternal side, that they might not be eligible for testing or that the risks might not be as high. But we know that we inherit half of our genetic information from our mom’s side of the family and half of our genetic information from our dad’s side of the family. So as part of the genetic counselling process, we really do incorporate the full family history on both sides and if someone does have a family history of cancer on their dad’s side of the family, it’s definitely something that is incorporated into criteria and offering genetic testing.”

The same principle also applies for males and a possible inherited cancer risk from the maternal side of their families, she stated.

“Yes, same thing with inheriting both of the information from both sides. Some of the genes that are associated with hereditary cancer syndromes are associated with cancers like breast and ovarian cancer in a female or prostate cancer in a male or breast cancer in a male so we really incorporate the information as a whole.”

What is Genetic Counselling?

Delivering a presentation on “Genetic Counselling and Hereditary Cancer” as part of this webinar, she explained that genetic counselling involves helping people understand and adapt to the medical, psychological and familiar implications of the genetic contributions to cancer and as genetic counsellors, they have specialized education in genetics and counselling that would help patients make important decisions as it relates to their genetic health.

She said that since the start of the COVID-19 pandemic, the clinic at the Princess Margaret Cancer Centre has transformed to working virtually and appointments and sessions are usually conducted either by phone or by video. A part of their genetic counseling appointment involves counsellors meeting with patients to increase their knowledge of what patients hope to gain and what their main concerns are.

Genetic counsellors also gather information about each patient’s personal and family history to garner a more in-depth understanding of a cancer occurring or recurring in their family and they provide education and counselling for those who are eligible to help to promote informed consent. This is followed by counsellors presenting patients with the various options available to them in terms of genetic testing and the types of results that might come back from a genetic test.

Meanwhile, the post-test appointment is where genetic counsellors discuss the results with patients and the implications for them and their families. If a genetic mutation that is associated with a hereditary cancer syndrome is identified, genetic counsellors can help facilitate cascade genetic testing, which would not only benefit the patients that they are seeing, but also their families, she said.

Identifying When Cancers Are Hereditary

Gillies explained that approximately five to 10 percent of all cancers are hereditary, 10 to 20 percent are caused by a combination of various factors including genetics and the environment while the remaining amount is intermittent.

“About 5 to 10 percent of all cancers are hereditary whereas about 10 to 20 percent is familial, caused by a contribution of many different genetic and environmental factors and then the other proportion is sporadic, caused by environmental factors like aging or hormones or other types of things.”

She said that when they look at a patient’s family history with the belief that this cancer could be hereditary, they are generally looking for evidence to support this theory and this could include factors such as multiple family members being diagnosed with cancer across many generations and persons in the family being diagnosed with more than one type of cancer among other factors.

“But when we are looking at someone’s family history and we have this question could the cancer be hereditary, we’re often looking for clues. So this could be multiple relatives in a family being diagnosed with cancer across several generations, people being diagnosed with rare cancers like male breast cancer, people diagnosed with more than one type of cancer like breast and ovarian cancer or people diagnosed with cancer at particularly young ages.”

When Cancers Are Not Hereditary Or Family History Is Not Known

The Genetic Counsellor said that there are also cases where patients may not have a strong family history of cancer or may not know their family history well enough to know if they do have a strong family history of cancer and this is where genetic testing plays a crucial role in helping them to identify those patients to find out if they have a hereditary cancer syndrome.

“However, what we know is that not all family histories of cancers look this significant. Many people don’t have strong family histories of cancer or they don’t know the details about their family history and they might still have a hereditary cancer syndrome. So that’s why genetic testing is so important and with the decreasing costs of genetic testing and increasing access to genetic testing through expanding eligibility criteria, we can really rely more on genetic testing to help identify more carriers to introduce early cancer detection and prevention as a whole.”

Introducing A Model Of Care Known As Mainstreaming

Gillies said that this would hopefully lead to early detection and prevention of cancer for their patients.

“So I think that this is what is so exciting about the universal genetic testing piece – or one of the very exciting pieces about it at least – and with all breast cancer patients being offered genetic testing, we can really rely less on complex eligibility in our family history and be able to identify more genetic carriers and improve early cancer detection and cancer prevention as a whole.”

This would help to increase the number of patients who would receive genetic testing and the Princess Margaret Cancer Centre plans to facilitate these patients through a model of care known as mainstreaming, where the oncologist would order the genetic test and then genetic counsellors would follow up with patients with written information explaining their results, what this means for them and their next steps, said Gillies.

“And as this really does increase the number of patients who would be receiving genetic testing, we plan to introduce this through a model of care known as mainstreaming, whereby the oncologist would order the genetic testing and then genetics would follow up with results and for patients whose results are normal, they would receive a letter to describe the results to them and for patients who have abnormal results, they would be booked an appointment in genetics and this model has been successful in the breast site previously and as with a number of the other cancer sites that we work with and really allows us to be more efficient, while still providing dedicated counselling and support for hereditary cancer families.”

Educational Resources for Breast Cancer Patients and Survivors

She stated that in order to support their patients with the whole genetic counselling experience, their clinic has developed several resources to help guide patients throughout the process. This includes a brochure that explains more about genetic testing and videos that describe the genetic testing process and the types of results that are likely to incur.

Gillies added that as a genetic counsellor, she feels “honoured” to support patients throughout their genetic counselling journey and with all of these new advances in genetic testing continually being unveiled, including the introduction of universal genetic testing in personalized genetic medicine, “it’s a very exciting time to be in genetics.”

References:

Breaking Ground: Moving Towards Universal Genetic Testing in Cancer