Can cancer be prevented?
Many people believe that getting cancer is purely down to genes, fate or bad luck. But through scientific research, we know that our risk actually depends on a combination of our genes, our environment and things to do with our lifestyle, which we’re more able to control.
Cancer is caused by damage to our DNA, the chemical instructions that tell our cells what to do. Things we come into contact with in our environment, such as UV rays, or through our lifestyle, such as the cancer-causing chemicals in tobacco, can damage our DNA. This damage can build up over time. If a cell develops too much damage to its DNA it can start to grow and multiply out of control – this is how cancer starts.
Find out more about what cancer is and how it grows.
Family history and inherited genes
Some people inherit damaged DNA from their parents, which can give them a higher risk of certain cancers. For example the BRCA genes are linked with breast, ovarian, prostate and other cancer. But the proportion of cancers caused by inherited faulty genes is small – experts estimate that only about 2 or 3 in every 100 cancer cases are linked to inherited gene faults.
Read more about inherited genes and cancer.
How many cancers could be prevented?
In the UK, more than 1 in 2 people will develop cancer at some point in their lives. Every year, more than 350,000 people are diagnosed with the disease. But experts estimate that more than 4 in 10 cancer cases could be prevented, largely through lifestyle changes, such as:
doing what you can to avoid certain infections (such as HPV or hepatitis)
being safe at work (see cancer risks in the workplace)
Surveys have shown that people aren’t necessarily aware that all of these things are linked to cancer. For example, studies have found that 15 in 20 people don’t know obesity causes cancer, and 18 in 20 people aren’t aware of the link between alcohol and cancer.
Need some inspiration?
Making lifestyle changes can be difficult, but there are so many benefits. Try to find ways to make it easier to get into healthy habits and stick with them, such as being active regularly with a friend, keeping track of what you eat or drink, or letting your friends and family know about what you're doing.
You can read our tips and advice for making lifestyle changes that could reduce your cancer risk in this section. And there are lots of other sources of information and support, such as the OneYou or Change 4 Life websites or your GP or pharmacist.
Can lifestyle changes really make a difference?
Yes, and not just for cancer. In 2008, a large UK study worked out how a combination of four healthy behaviours would affect your health. These were: not smoking; keeping active; moderating how much alcohol you drink; and eating five daily portions of fruit and vegetables.
People who did all four healthy behaviours gained an average of 14 years of life compared to people who didn’t do any of them.
You can read more about this study on our Science Blog.
Is prevention a guarantee?
‘Healthy living’ is not a cast-iron guarantee against cancer. But it stacks the odds in your favour, by reducing the risk of developing the disease.
For example, we know that it’s possible for a heavy smoker to live a cancer-free life, while someone who never touches cigarettes could develop lung cancer. But lots of large long-term studies clearly show that people who have never smoked are far less likely to develop or die from cancer than smokers.
In the same way, careful drivers cannot guarantee that they will never get into an accident due to events beyond their control, but they are much less likely to do so than reckless ones.
You can read more about understanding risk on our Science Blog.