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.
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:
keeping a healthy bodyweight
eating a healthy, balanced diet
cutting back on alcohol
enjoying the sun safely
doing what you can to avoid certain infections (such as HPV or hepatitis)
being safe at work
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.