Breast Cancer Genetic Testing, Know Your Options.

PERSONALIZED MEDICINE AND BREAST CANCER GENETICS, KNOW WHEN GENETIC TESTING MATTERS

Over the past few years, research has provided new understanding in the realm of breast cancer genetics, helping individuals and medical specialists to better predict this leading cause of cancer-related mortality amongst women worldwide. Genetic testing for inherited gene mutations can help guide treatment and better inform those at risk of acquiring breast cancer. In addition to treatment becoming personalized, rehab can also become more personalized, tailoring to your risk factors and needs.

Environmental factors and healthy behaviours play a very important role in determining cancer risk; however, through genetics we have come to understand that there is more to the puzzle. We’ve now come to understand that some people unfortunately get cancer simply because it is written in their genetic code despite their efforts to live a healthy lifestyle.

Removing the shame around a diagnosis is important.

Often those with cancer ask themselves what did I do wrong? Genetics can be influenced by non-modifiable and modifiable risk factors. How you are born in one thing, but the environmental influence on gene expression also matters and is known as epigenetics. Sometimes the dance of nurture vs nature isn’t predictable, so tools such as genetic testing can help reduce risk and remove shame.

Personalized Oncology and Precision Breast Cancer Treatment

Understanding your genetic code through tissue biopsy and detecting other cell markers, can help an oncologist individualize a breast cancer diagnosis and personalize a treatment plan. This is known as precision or personalized medicine. Take drug-gene testing as an example; genetic testing can help decipher how particular medications are metabolized in your body aiding the personalization of type and dose. Decoding relevant genetic information, together with understanding tumour properties such as HER2 or hormone sensitivities can help optimize treatment.

Learn more about managing hormone therapy

For example, BRCA gene carriers are associated with increased sensitivity to platinum-based chemotherapy drugs called PARP inhibitors. Triple negative breast cancer (i.e., no hormone sensitivities and Her2 protein) often carry BRCA mutations and can be targeted with specific therapies. Furthermore, genetic testing can help determine Oncotype which can help to better predict the likelihood of recurrence and the efficacy of chemotherapy in early-stage hormone-positive breast cancers.

Breast Cancer Genetics, What We Know

Breast cancer can be hereditary, involving one or both mutations on the BRCA1 or BRCA2 gene. The medical term for carrying a mutation(s) of the BRCA gene is termed ‘hereditary breast and ovarian cancer syndrome HBOC’. This syndrome demonstrates that carrying the BRCA gene involves increased risk of acquiring breast, ovarian, pancreatic, and possibly other cancers. Females with HBOC have a 70% chance of breast cancer onsetting prior to the age of 80.

Men carrying a BRCA1 or BRCA2 gene are at increased risk of breast cancer, prostate, pancreatic and possibly other cancers. There are many other known genes that are linked with breast cancer risk, such as ATM, PALB2, TP53, CHEK2, PTEN, CDH1, STK11 however the risk remains lower. In addition, there are several common genetic variants known as (SNPs) that can modestly increase breast cancer risk.

Learn more about our breast cancer services

Genomic Testing Innovation

Technology has radically changed genetic testing. Nowadays, it is relatively affordable and accessible through mail. Tumor DNA can be detected in blood, non-invasively known as a liquid biopsy, promising early breast cancer detection. Saliva testing may also be an option. In addition, advancements such as next-generation sequencing (NGS) enables the analysis of multiple genes at once.

Why Consider Genetic Testing for Breast Cancer?

Here is Canada, the guidelines for genetic testing are still in development hence there is not clear cohesion within the medical community as to when it is necessary or how to use the mathematical models to guide decision making. Hence genetic testing isn’t always covered by MSP here in BC or discussed. I do however have many patients who opt to pursue genetic testing privately through companies in the United States as there aren’t any options in Canada.

The American Cancer Society has recommended breast cancer genetic testing for those who fall into the following categories:

Individuals with breast cancer:

Women diagnosed at a younger age
Women with triple-negative breast cancer
Women who are of Ashkenazi descent
Women with a family history of breast, ovarian, pancreatic or prostate cancer
Men diagnosed with breast cancer

Individuals without breast cancer but fall within the following:

Known family history of BRCA gene mutation(s)
Known family history of breast cancer at a younger age
Known family history of a close family member with ovarian, pancreatic or metastatic prostate cancer
Women diagnosed with ovarian or men diagnosed with pancreatic cancer

If genetic screening isn’t an option for you, knowing family history for ovarian, pancreatic, prostate and breast cancer can be of similar insight. Further research has shown that having a first degree relative (daughter, sister or mother) who has or has had breast cancer doubles your risk, 2 relatives with a diagnosis can increase the risk 3 fold.

Companies Offering Breast Cancer Genetic Analysis in North America

As there are no companies directly in Canada, Canadian medical oncologists are working closely with the following American genetic testing companies:

Myriad Genetics, one of the most well-known genetic testing companies in the world; offers myRisk hereditary cancer test screens for multiple gene mutations including BRCA1 and BRCA2.
Ambry Genetics is offering CancerNext, a comprehensive hereditary cancer panel.
Invitae is offering a comprehensive genetic test for hereditary breast cancer risk including BRCA1 and BRCA2
Color Genomics offers a hereditary cancer risk panel screening for mutations in 30 genes.
Quest Diagnostics provides several genetic tests including BRCA1 and BRCA2

If you fall into one of the recommended categories above, please consider speaking to your oncologist or us here at the cancer physio to take first steps for genetic testing. A genetic test may be the gateway to more personalized treatment and risk reduction for yourself and others.

Consider a Genetic Test, Risk Reduction awaits.

REHAB CONDITIONS TREATED:

Prehab concerns, post-operative swelling, post-operative pain,
muscle weakness, joint stiffness or pain (arthralgia and myalgia)
adhesive capsulitis, rotator cuff strain, axillary chording and thoracic chording
scar adhesions, scar related pain amongst others.
lymphedema risk management
concerns about return to work and sport
neuropathies, neuropathic pain, chemotherapy induced peripheral neuropathies
spinal accessory nerve neuropraxia, long thoracic nerve palsy, spinal accessory nerve palsy
cranial nerve dysfunction and many others
dizzyness, balance concerns, nausea, light-headedness, exertional/exercise sensitivities, chemotherapy induced vestibular neuropathies, BPPV, vertigo amongst others.
Chemotherapy induced muscle wasting (cachexia), cardio-toxicity and neurotoxicity
cancer related fatigue
chemotherapy induced peripheral neuropathies, chemotherapy induced vestibular neuropathy, neutropenia/NADIR (other blood cell deficiencies)
concerns about return to work and sport
radiation fibrosis syndrome including but not limited to: adhesive capsulitis/frozen shoulder, cording, scar tension/pain, shoulder stiffness/pain, neck stiffness/pain, lymphedema,
radiation induced vestibular neuropathy
pneumonitis, changes in bladder/bowel functioning,
neuropathies amongst others.
AIMS (aromatase Inhibitor musculoskeletal syndrome):
nausea, hot flashes, sleep disturbances, joint pain/stiffness, osteopenia, sexual dysfunction,
concerns about return to work and sport