The PMCC to Conduct Genetic Testing for All Breast Cancer Patients

By Patricia Thangaraj

Starting in the Fall of 2022, the Princess Margaret Cancer Centre will conduct genetic testing for all breast cancer patients for over 75 genes associated with hereditary forms of cancer.

This is according to Medical Geneticist and Medical Director, Genetics and Cancer Early Detection, Princess Margaret Cancer Centre, Dr. Raymond Kim who delivered a presentation on “Breaking Ground: Universal Genetic Testing and Cancer Early Detection” as part of a webinar entitled “Breaking Ground: Moving Towards Universal Genetic Testing in Cancer.”

He said that this would apply to patients with a large 75 gene panel and it includes those patients who otherwise would not have had the opportunity to be tested because they do not fall under the Ministry of Health guidelines for genetic testing.

“The PM genetics team continue to push the boundaries in clinical care. As of the Fall of 2022, we would be testing all breast cancer patients with a large 75 gene panel – with support from the PM Foundation and its donors – and this includes patients who otherwise would not have been covered in the Ministry of Health’s updated guidelines.”

He explained that cancer is caused when cells divide uncontrollably and spread into surrounding tissues. “Cancer is caused by genetic changes, which results in cells to grow uncontrollably and form masses or tumours in the body that can move or metastasize as the doctors call it.”

There are a number of reasons why these genetic changes can occur. However, there are also related to genetic mutations, explained Dr. Kim.

“Now these genetic changes can be caused by environmental factors such as UV light if you’re sitting out in the sun, some chemicals, viruses like human papillomavirus, smoking and some inflammatory states where cells divide very quickly. But some of these changes are hereditary or inherited and about 10 percent of all cancers are caused by this type of genetic change.”

Focussing on BRCA Gene Mutations

Dr. Kim said that the PM Cancer Centre team at The Bhalwani Familial Cancer Clinic focus their efforts on these types of cancers. He said that persons who have a BRCA1 or BRCA2 gene are more likely to develop breast or ovarian cancer. Prostate and pancreatic cancers are also likely to occur.

He said that one of their goals at the PM Cancer Centre is to manage these high-risk previvors using MRIs and then based on their results, recommend the next steps that they must take to protect themselves from developing cancer.

“These patients have a 70 percent lifetime cancer risk and they have a predictable lifecycle where they are born with a genetic change, but are cancer free – we call them previvors – and then we manage them with intensive surveillance with MRIs and tell them to remove their breasts and ovaries as potential options to prevent cancer.”

However, in spite of their best efforts, many of these persons do go on to develop cancer and in those cases, the PM Cancer Centre team would put them on personalized treatments based on their specific gene mutation and if patients survive, clinicians will then continue with their surveillance.

Regrettably, due to genetic changes in their body, these patients can get another cancer and therefore, the goal of their team is to use genetic testing to identify these patients and their families.

“Unfortunately in spite of this, many of them do develop cancer and often receive personalized treatments with targeted therapies designed around their gene mutation and if they survive their cancer, they continue with their surveillance and this cycle continues and unfortunately, very often, they can get another cancer because of these genetic changes throughout their body. So we identify these patients and their families through genetic testing and they do provide an opportunity for all cancer patients for precision cancer and early detection.”

Dispelling the Genetic Myths

He said that there are a lot of myths surrounding genetic testing. One of these myths is that persons would be discriminated against because of their genetic condition. Dr. Kim said that in 2017, the Bill S-2O1 was passed, where Canadian employers and companies of goods and services such as disabilities and life insurance cannot ask about the results of genetic testing.

Another myth is that there is a cost associated with genetic testing. However, most genetic testing is covered by public health care and the cost of genetic testing has been reduced from a $1000 per gene several years ago to approximately a $1 a gene using some technologies.

A third myth is that children would carry a gene mutation. However, clinicians are working to ensure that this is not a reality. “There is a myth that children would carry a genetic mutation and for decades, we in the genetics field have been able to select out embryos which carry the gene so future generations are liberated from their ancestors cancer risk.”

He added that genetic conditions are no longer considered taboo as a result of the “Angelina Jolie effect.”

Treating Cancer Patients with Specific Therapies

Dr. Kim explained that there are various types of targeted cancer drugs that can be used to treat cancer patients based on their specific gene mutation.

“Now as mentioned, hereditary gene mutation carriers have developed specific therapies based on their identified gene mutation. This has been applied to other non-carriers who share that same genetic change, but actually only in their tumour and some examples are listed here such as PARP inhibitors for BRCA, rank ligand inhibitors and immunotherapy in Lynch syndrome or colon cancer and endometrial cancer.”

Advancing Genetic Testing During COVID-19

Dr. Kim stated that the PM Cancer Centre genetics team needed to find ways to keep updated with the “genetic revolution” and with support from the Bhalwani Familial Hereditary Cancer Fund, they increased their team by two-fold, developed new models of genetic testing and counselling and became a provincial and national leader in cancer genetics.

He stated that many members of this Bhalwani Familial Hereditary Cancer team charted the path for Ontario Health, who implemented updated genetic testing guidelines back in April, May and September of 2021 and these testing guidelines drastically increased access to genetic testing for all cancer patients. However, in spite of these improved guidelines, not all gene carriers are being identified.

Therefore, their next steps at the PM Cancer Centre would be to ensure that all cancer patients, especially breast cancer patients can be tested as there are benefits to this.

“Recent studies have shown that testing all cancer patients, in particular breast cancer patients has a high gene mutation detection rate. The American Society of Breast Surgeons recommends all breast cancer patients should have genetic testing.”

He said that a major study from the Mayo Clinic was published earlier last year and the lead author of that study, Dr. Keith Stewart became the Vice President, Cancer and Director of the Princess Margaret Cancer Program, UHN, enabling the PM Cancer Centre to place cost-effective universal genetic testing at the forefront of the services that they offer.

A New Focus for the Princess Margaret Cancer Centre

Dr. Kim stated that under Dr. Keith Stewart’s leadership, the PM Cancer Centre genetics team have shifted their focus from tough to treat cancers to detecting cancers at its earliest stages, where finding cures is still a possibility. These treatment options would consist of genetics, radiology, biomarkers, supportive care, pathology and chemoprevention.

He said that some of the questions that he gets asked often is how persons can break their cycle. “One of the questions I often get asked from my patients is how can we break this cycle? How can I predict if my cancer will come? Where on the cycle do I sit?”

Referring to a diagram, he said that there is a blood test that can predict when certain cancers come along.

“Now, there is a concept known as cell free DNA or liquid biopsy in patients who do have a cancer. And what happens when patients progress from healthy patients to a cancer patient is that their cells start to grow uncontrollably and some of them invariably die. And when cells grow quickly into tumours, they often release the DNA – small bits of DNA – that we can detect in the patient’s blood using modern, sensitive technology.”

He continued, stating that they can then use liquid biopsies as opposed to taking a surgical sample from a tumour with a biopsy.

“These small bits of DNA are called cell free DNA and it occurs in various health states and in cancer as I mentioned, we call it a liquid biopsy, where these genetic changes are detected in liquid whereas taking a surgical sample from a tumour with a biopsy.”

Charting a New Path for BRCA Carriers

He stated that one of the ways that this would change the cancer journey of those who carry the BRCA1 or BRCA 2 gene is that they would be able to better predict a carrier’s risk of developing cancers associated with these gene mutations.

“In a patient like Angelina, who is currently healthy, we present her with some statistics about some other carriers. She would have a 75% risk of breast cancer, a 40% risk of ovarian cancer etcetera and with these generalized numbers, how is she supposed to know which applies to her? And when her cancer ticking time bomb would go off.”

He said that if people have read her medical choice in the New York Times, they can get an idea as to the inner turmoil that carriers face.

From here, the PM Cancer Centre team can then tell their patients about their specific cancer risks and map out a recommended treatment plan for these persons.

“So what we would like to do is to give a precise cancer risk to carriers by using cell free DNA, a blood test with a liquid biopsy to provide a personalized future cancer risk. We would be able to tell you that based on your cell free DNA, liquid biopsy profile, your breast tissues seem to be turning over quickly. So it is time to remove your breasts or we can say that your ovarian tissue cells seem to be quiet, so you can keep your ovaries for the time being and consider having that next child instead of removing them. A simple blood test to answer a complex question for our patients is what we are trying to do at the Princess Margaret.”

Dr. Kim concluded by stating that the team at the PM Cancer Centre are planning ahead for the future of cancer care and the “future is bright with our DNA being our lighthouse.”

References:

Breaking Ground: Moving Towards Universal Genetic Testing in Cancer: https://www.youtube.com/watch?v=XdMrhlsqbgM