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Smoking and cancer

Smoking is the single biggest cause of cancer in the world.Thanks to years of research, the links between smoking and cancer are now very clear. Smoking is by far the most important preventable cause of cancer in the world. Smoking accounts for more than one in four UK cancer deaths, and nearly a fifth of all cancer cases.

Tobacco was responsible for more than 100 million deaths worldwide in the 20th Century. The World Health Organisation has estimated that, if current trends continue, tobacco could cause a billion deaths in the 21st Century.

Which cancers are caused by smoking?

Smoking causes more than four in five cases of lung cancer. Lung cancer has one of the lowest survival rates of all cancers, and is the most common cause of cancer death in the UK.The good news is that most of these deaths are preventable, by giving up smoking in time.

Smoking also increases the risk of at least 13 other cancers including cancers of the larynx (voice box), oesophagus (gullet), mouth and pharynx (throat), bladder,pancreas, kidney, liver, stomachbowelcervix, ovary, nose and sinus, and some types of leukaemia. There is also some evidence that smoking could increase the risk of breast cancer.


tobacco causes at least 14 types of cancer

Not all smokers get cancer. Why?

You may know someone who smoked all their lives but lived to a ripe old age. Or you may know someone who never smoked but got cancer anyway. Does this mean that smoking doesn’t really cause cancer?

Not at all. Years of research have proven that smoking causes cancer. But this doesn’t mean that all smokers will definitely get cancer or that all non-smokers won’t. It means that smoking greatly increases the risk of this disease. Smokers are, on average, much more likely to get cancer than non-smokers.

In a similar way, we can say that eating sugary foods is a cause of tooth decay. This doesn’t mean that all children who eat sugary foods will end up with decayed teeth. It means that, on average, children who eat lots of sugary foods are more likely to develop tooth decay than those who avoid such foods.

The fact is that half of all long term smokers eventually die from cancer, or other smoking-related illnesses. And half of those will die in middle age, between 35 and 69.

Our stats and evidence page has more information on the evidence linking smoking to cancer.

How does smoking cause cancer?

Tobacco smoke contains more than 70 different substances that are thought to cause cancer. When you inhale smoke, these chemicals enter your lungs and spread around the rest of your body.

Scientists have shown that these chemicals can damage DNA and change important genes. This causes cancer by making your cells grow and multiply out of control.

Check out our How smoking causes cancer page for more detail.

Giving up makes a difference

Thanks to research, new policies and improved public awareness of the benefits of quitting, the proportion of smokers in the UK has halved in the last 50 years. Because of this, the rate of people dying from lung cancer has been decreasing steadily since the 1980s. It takes time to see the benefit but giving up smoking saves lives.

There is still a long way to go. One in five people in the UK still smoke and smoking-related diseases kill over 100,000 people in the UK every year.

If you are a smoker, giving up smoking is the best present you can give yourself, your friends and family. There are many techniques you can try to help you join the hundreds of thousands of smokers who’ve already quit for good. For more information and advice on quitting, visit reducing the risk or the NHS smokefree website.

Giving up smoking can reduce your risk of cancer, heart disease, stroke and many other conditions. Find out more about smoking


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Updated: 5 September 2014