Genetic Testing for Targeted Cancer Therapy

In order to understand the importance of genetic testing for targeted cancer therapy, it is helpful to understand a little bit about how genes are involved in cancer development and proliferation.


Hello. This page will tell you more about Genetic Testing for Targeted Cancer Therapy. If you’d like specific detail on the tests we have identified as the best available for successful Targeted Cancer Therapy at this time, just explore these pages:

Genetic Testing of Your Cancer Tumour Tissue: Targeted Cancer Therapy

Liquid Biopsy (ctDNA, cfDNA) Testing for Targeted Cancer Therapy and Non-Invasive Treatment Monitoring

Otherwise, please have a read below to learn about the basics of genetic testing and why it is so important to the outcome of your cancer treatment:

How Exactly are Your Genes Involved in Your Cancer?

Genes are pieces of DNA (deoxyribonucleic acid) inside each of our cells that instruct them how to make the proteins the body needs to function. DNA is the genetic “blueprint” found in each cell. Genes affect inherited traits passed on from a parent to a child, such as hair colour, eye colour, and height. They also affect whether a person is likely to develop certain diseases, such as cancer.

In humans, genes are located on 23 pairs of long strands of DNA called chromosomes. One of each chromosome pair comes from the mother, and the other from the father. Each chromosome can contain hundreds or thousands of genes that are passed from the parents to the child. The genes you were born with are in every cell in your body.

Changes to your genes, called mutations, play an important role in the development of cancer.

Mutations can cause a cell to make (or not make) proteins that affect how it grows and divides into new cells. Certain mutations can cause cells to grow out of control, which can lead to cancer. Usually several gene changes are needed before a cell becomes a cancer cell.

Only about 5% to 10% of all cancers are thought to be related to an inherited gene change that strongly affects a person’s risk for a certain type of cancer. (

Most cancers start because of gene mutations that happen sometime during a person’s lifetime. Sometimes these gene changes have an outside cause, such as exposure to sunlight or tobacco. But gene changes can also just be random events that sometimes happen inside a cell, without a discernible cause.

What is Genetic Testing for Targeted Cancer Therapy?

Genetic tests for targeted cancer therapy detect changes (mutations) in the DNA of cancer cells.

Knowing whether your cancer has a particular mutation helps your treatment team to select the best possible treatment for you as the presence or absence of certain mutations can predict which treatments you will benefit most from and which you will not respond to.

As described above, cancer is the uncontrolled growth of abnormal cells. Multiple factors may contribute to this uncontrolled growth. One such factor is the malfunctioning of certain proteins involved in controlling cell growth and maturation. The proteins usually malfunction as a result of a mutation in the DNA of the gene that codes for that protein.

Some mutations may result in a defective protein that cannot stop cell growth while other mutations may produce a protein with altered function that stimulates cell growth. Either way, the end result is unchecked growth and division of these abnormal cells, which we call cancer.

Medical researchers have long studied these changes in genes in order to better understand cancers and to develop drugs to fight them. Their goal has been to create drugs that disrupt a specific step in cancer growth, while doing minimal damage to the normal cells surrounding the tumour, or throughout your body at large. These are called targeted cancer drugs and the process is called targeted cancer therapy.

What researchers have noted is that specific types of cancer are frequently associated with specific genetic mutations. Not every cancer will have the same mutations, but a significant percentage of a certain type of cancer will have a similar mutation. Cancers with these mutations usually have a more predictable response to certain drug treatments compared to cancers without these mutations.

It is important to note that most tumours typically have more than one mutation driving them. This means that while oncologists can often make a fair guess that one common mutation might be involved, for the most successful cancer treatment outcome, your doctor must also be aware of which other mutations are present.

Having a clear picture of all of the mutations that are triggering your cancer or supporting it to proliferate is key to ensuring that the treatment you receive takes all of your mutations and their interplay into consideration, not just one.

Additionally, it is crucial to ensure that the treatment you engage in to target one genetic mutation does not lead to increased growth in another, as can frequently happen when targeted therapy regimes do not consider the interplay between mutations.

To ensure that you are getting the right treatment that considers these key factors of mutations and their interplay, medical science has developed a variety of genetic tests to detect the presence of mutations in cancer tissue that tell a doctor whether the person being tested is likely to benefit from a specific therapy. 

Why is Genetic Testing Important for Targeted Cancer Therapy?

Standard treatment for cancer usually involves surgery, chemotherapy, radiation therapy or some combination of these. Treatment with chemotherapy drugs and radiation aims to slow the growth of cancer, keep it from spreading, and kill any cancerous cells that have spread to other parts of the body (metastasized).

Chemotherapy works by attacking cells that are actively growing and dividing. Radiation therapy kills cancer cells by damaging their genes and preventing them from growing and dividing. Both types of therapy can affect all cells that are growing and dividing in your body, including normal cells. This often leads to harmful side effects such as the potential for the creation of new mutations, in addition to common symptoms such as hair loss, nausea and fatigue.

Additionally, these old, standard treatments require careful adjustment to maximize the killing of cancer cells while minimizing the damage to healthy tissue, which is difficult to do when the treatment is affecting all dividing cells and not just the cancerous ones.

Targeted cancer therapy is a newer type of cancer treatment that offers doctors and their patients the opportunity to use a drug that has a greater effect on cancerous tissue, while reducing many of the side effects associated with standard therapy.

It is based on the fact that the genetic makeup of the cancer cells is different than that of the healthy cells around them. With targeted cancer therapy, a drug specifically designed to target only those cells with a particular mutation is used to disrupt specific steps or processes that are unique to the cancer cells in your tumour.

How is Genetic Testing for Targeted Cancer Therapy Accomplished?

For detailed information on the specific genetic tests we highly recommend and how they work just visit our detailed page for each test.

In general, genetic tests for optimal cancer treatment currently work in one of two ways:

  1. Liquid Biopsy (a.k.a. ctDNA or cfDNA):

In this form of genetic test for cancer a sample of your blood plasma is obtained through a simple blood draw at the CTOAM testing facility and is then tested for a short list of common mutations.

This test, called a liquid biopsy, and also known as a circulating tumour DNA (ctDNA) or cell free DNA (cfDNA) test, is very useful when your treatment team suspects a certain mutation is involved in your cancer and wants to know for sure and quickly.

The turnaround time for this test is typically less than one week. This means that fewer than 7 days from the day of your blood draw you can have confirmation as to whether certain key mutations are driving your cancer to proliferate. Within one week you can know that the treatment you are getting is the right one for you.

  1. Genetic Tumour Tissue Testing: Targeted Cancer Therapy:

In this form of testing, a slide of your tumour tissue (from a previous biopsy) is tested for a large panel of genetic mutations. This test takes a little longer (typically 3 weeks for the test to be completed once the lab has received a sample of your tumour tissue), but is a far more detailed panel than a liquid biopsy test.

The Detailed Genetic Testing panel that we use looks at well over 300 possible mutations that are known to influence the development of cancer and which are considered targetable because there are specific treatments available that target those mutations directly.

The results this test produces give you a very clear picture of the key mutations that are involved in your cancer, and allow our researchers to explore all possible targeted cancer therapy options available for you, worldwide.

 How to get genetic testing for cancer?

If you would like to have confidence, based on solid, peer-reviewed science and the most advanced technology available today, that you are getting the best possible treatment for your cancer, contact us to find out more or to arrange for your genetic test for targeted cancer therapy today.