Cancer in families (genetics)

If someone in your family has cancer, you may wonder if you are at risk of developing it yourself, or passing it on to your children.  

This page has information about cancer in families and how Maggie's can help.

Why might cancer run in families?

When members of the same family have cancer it can be because of:

• Coincidence or chance
• Shared lifestyle or environment like smoking, exposure to the sun, chemicals, alcohol, being overweight, and getting older
• An inherited faulty gene that makes it more likely you'll develop cancer

Risk of developing an inherited cancer

For a few families, there can be a strong family history of cancer.  

When doctors look at the possibility of a genetic cancer gene in your family, they consider a number of things:

• How many close relatives have had cancer
• How old they were when they developed it
• If there has been a combination of cancers, such as breast and ovary, or bowel and womb
• Whether there has been a rare cancer in the family
• Your ethnicity – some family groups have a higher risk of inheriting certain cancer genes
• Your age

You may be referred for genetic testing if you have a strong family history of cancer, or a hereditary cancer gene has been found in another close blood relative. 

If you're worried about your genetic cancer risk, talk to your GP. 

Genetic testing

Genetic testing looks for inherited faulty genes that may go on to develop certain types of cancer.

If you've been referred for genetic testing by your GP, you will see a specialist genetic doctor or counsellor who will look through your family history and assess your risk.

They will also discuss the positives and negatives of having genetic testing done.

They may then recommend a blood test from you and other family members.

Genetic testing and emotions

Genetic testing can cause a range of emotions before and after you get the results.

Making a decision about whether to have a test or not can be difficult and you and your family may have different opinions.

If results reveal you have a faulty gene, you may need time to absorb the information and wonder what to expect in the future.

If your results are negative, you might feel mixed emotions – relief for yourself but upset if members of your family have tested positive.

If you test positive

If you test positive for an hereditary cancer gene it means you have a higher risk of developing cancer in the future.

Depending on the type of faulty gene you may be offered:

• Regular screening – for reassurance and to pick up possible cancer early
• Surgery or medication – to prevent cancer developing
• Information about lifestyle changes to reduce your risk

Maggie's is here with you

We are here for you and your family before, during and after genetic testing.

Our Cancer Support Specialists are here to listen to your concerns and help you find the information and help that's right for you:

• Find your nearest Maggie's centre – you don't need an appointment, just come in

Last review: Oct 2021 | Next review: Oct 2022