With record numbers of people having bowel cancer checks following the death of cancer campaigner Dame Deborah James, and the passing of Olivia Newton-John thrusting breast cancer back into the spotlight, there’s never been a better time to take control of your health. 

With 1 in 2 of us likely to develop cancer at some point in our lives, genetic cancer testing is one way to check your risk levels for certain cancers and gain some peace of mind that you’re fully prepared for the possibility of it happening to you. 

Of course not all cancers are hereditary – other lifestyle aspects such as diet, exposure to UV rays and smoking can all play a part – but knowing whether you’re predisposed to a particular type of cancer can give you vital information to make important decisions about your health. 

With that in mind, here’s our guide on everything you need to know about genetic cancer testing so you can decide if it’s right for you. 


What is cancer genetic testing?

Genetic cancer testing checks your DNA for the presence of certain genetic mutations inherited from parents that increase the likelihood of developing specific cancers, such as breast or bowel cancer. If you’ve inherited a gene mutation (which you have a 50% chance of if you have a parent with it), you have a higher risk of getting that particular type of cancer. 

Because the gene mutations involved in susceptibility to certain cancers have been identified, we can look for them as markers of potential cancer in the future. Cancer genetic testing will check your risk levels for certain types of cancer, depending on what type of test you take. 

It’s estimated that inherited mutations account for between 3% and 10% of all cancers. It’s important to remember though that, even if you find you have inherited a particular variant, that doesn’t mean you definitely will develop that specific cancer. Lifestyle factors also have an impact on the extent to which a gene mutation is expressed in the form of cancer.


What cancers can be detected through a genetic test?

There are many gene variants that have been identified as influencing a person’s cancer risk and which can be tested for, but some of the most common include:

  • Breast cancerbreast cancer genetic testing can detect the BRCA1 & BRCA 2 genes which can lead to the disease developing, along with other gene variants linked to breast cancer.

  • Bowel/colorectal cancer – only around 5% of bowel cancers are associated with a gene mutation, but there are some conditions which are linked to genes and that can lead to colorectal cancer.

  • Prostate cancer – several genes and chromosomal abnormalities have been identified as increasing the risk of developing prostate cancer and it’s estimated that 5-9% of all cases are due to hereditary genes.

  • Skin cancer (melanoma) – melanoma can run in families; one in every 10 people diagnosed with the disease has a family member who has also had it. There are certain gene mutations which can lead to an increased risk of developing skin cancer, and these can be detected with genetic cancer testing


Who should get genetic testing for cancer?

It’s important to take a detailed look at your family history when deciding if it’s worth getting tested for hereditary cancers; in particular, look at aspects such as:

  • Whether multiple family members (on the same side of the family) have all developed a particular type of cancer, particularly across generations.

  • Cancer that was diagnosed in a family member at an early age (before the age of 50).

  • A family member developing several different types of cancer.

  • Unusual cases of a specific cancer in the family, such as male breast cancer. 

  • Cancer occurring in both of a set of organs, e.g. breasts or kidneys. 

If any of these apply to your situation, you may want to think about genetic cancer testing.


What are the benefits of getting a genetic cancer test?

As with many things in life, it’s useful to weigh up the pros and cons when making important life decisions. When it comes to deciding whether to have genetic cancer testing, there are various advantages which you might think make it worthwhile, including:

  • The chance to prepare yourself and modify your lifestyle and any medication you take to reduce your risk of developing a specific cancer as much as possible; for example, you may wish to eat a more balanced diet, take up regular exercise or quit smoking so you can lead as healthy a lifestyle as possible.

  • If you have children and get a positive result, you can give them vital information they need to make important decisions about their health; after all, there’s a 50% chance they’ll be carrying the genetic mutation as well, and knowing this may prompt them to get tested so they can also prepare themselves.

  • A positive genetic cancer test result can lead to you getting cancer screenings more frequently (and checking your body yourself regularly) and from a younger age, increasing the chances of spotting cancer early before it spreads and becomes more dangerous.

  • You can take proactive action to prevent the cancer developing by having tissue removed, for example, by having a mastectomy in the case of breast cancer.

  • If you get a negative result, it may ease any anxieties you have and give you peace of mind that your chance of getting a specific cancer is no higher than that of the general population.

  • If you’ve already been diagnosed with cancer, a positive genetic cancer test result can help you make informed decisions about your treatment. 


What does it tell you?

Taking a genetic cancer test will tell you whether you have inherited a gene mutation from one of your parents which increases the likelihood of you developing a certain type of cancer. Your risk factor will be compared to that of the general population who don’t have the faulty gene. If you already have cancer, a positive result can confirm that your cancer likely developed due to the presence of this mutation. 

A negative result indicates that the test did not find the specific mutation it was designed to detect. You can then rest assured that you don’t have an increased risk of developing that particular cancer, although of course that doesn’t mean that you definitely won’t.

Sometimes the result is uncertain, which means that it doesn’t help to determine a person’s risk factor for that cancer. In some cases a benign variant is found – this is a genetic change (called a polymorphism) common among the general population and which does not indicate any increased risk of getting certain cancers. 

Is it accurate?

As with other health tests, cancer genetic testing is not perfect, but it does give you an opportunity to detect any genetic mutation associated with a specific cancer that you might be carrying and take precautions to reduce your risk. It doesn’t, however, rule out the presence of any other mutations you might have which could also lead to developing a certain cancer.

If you have a family history of breast cancer, for example, and you test for the BRCA genes commonly associated with hereditary breast cancer, the result may come back negative; however, you could still be carrying other inherited gene variants which can increase the risk of the disease but which were not tested for.

There are likely certain gene variants that increase the chances of getting specific cancers which we haven’t identified yet and therefore can’t test for. 

Are there any disadvantages to
genetic cancer testing?

Although getting tested for hereditary cancer genes can give you a feeling of control over your health, there are some potential drawbacks to think about.

There’s always the chance of receiving an inconclusive test result which might leave you disappointed, and you may worry about being discriminated against due to a positive result. Discovering you do carry a genetic mutation associated with an increased cancer risk could also leave you feeling more anxious than if you didn’t know at all. Then of course there’s the cost of private genetic cancer testing.

Although these are valid concerns, you’ll probably realise that gaining such valuable information about your health is priceless, and getting the opportunity to forearm yourself in this way is something to be embraced rather than feared. It can ease any anxieties you have about developing a specific cancer, and that peace of mind is something you can’t put a price on.

How is genetic cancer testing done?

Tests for genetic cancer are usually done by taking a sample of tissue or bodily fluids, such as blood, saliva or skin cells. The sample is then sent to a specialised laboratory to analyse the results. The laboratory technicians look for specific genetic mutations associated with certain types of cancers.  

Cancer genetic testing can be done at home using a test kit or at a specialised clinic. 

How long does it take to get the results of a
private genetic cancer test?

It usually takes a few weeks to get the results as your DNA needs to be analysed thoroughly to detect cancer-causing genes. 


How much is private cancer genetic testing?

The cost of getting a private genetic cancer test varies, depending on the provider and whether you take the test at a clinic or have a test kit delivered to your home. It also depends on the type and complexity of the test you take, for example, if you’re testing for multiple gene variants this will cost more. You might think it’s worth spending the money though for peace of mind or the chance to take control of your health. 

Where can I get
genetic testing for cancer?

If you’re having a cancer genetic test privately, you can take the test either at a local clinic or at home using a home testing kit.

Goodbody offers a range of home testing kits to detect specific cancers such as bowel, breast, prostate and skin cancer, as well as a complete cancer DNA test to check your risk of developing 8 types of cancer.

All of these genetic tests for cancer can be done at home by providing a saliva sample which is then posted to one of our specialised laboratories. You’ll then receive the results in 3-4 weeks. It’s a stress and hassle-free process.

Check out our extensive range of genetic cancer tests here.