Smoking and Lung Cancer

It has long been established that smoking causes lung cancer.Footnote 1 Footnote 2 Footnote 3 Footnote 4 Footnote 5 

Read more about lung cancer...


The risk of lung cancer increases sharply with the amount smoked,Footnote 6  the number of years one has smoked,Footnote 7 and the earlier one had started smoking.Footnote 3 Lung cancer risk also increases with the age of the smoker.Footnote 7

The risk of dying from lung cancer is up to 25 times greater among smokers than people who never smoked, depending on how much they have smoked.Footnote 2, Footnote 8

Only 16% of people diagnosed with lung cancer are expected to be still alive 5 years after diagnosis.Footnote 9  There were 18,560 deaths from lung cancer in Canada in 2007.Footnote 10  Research has shown that in 2002, almost 80% of lung cancer deaths were due to smoking.Footnote 11

Among people who have never smoked, long-term exposure to second-hand smoke also causes lung cancer.Footnote 12In Canada, 252 non-smokers died in 2002 from lung cancer due to exposure to second-hand smoke.Footnote 11  The lung cancer risk from second-hand smoke exposure is 20% to 30% higher for those living with a smoker.Footnote 12

These health warning messages address lung cancer for cigarettes and little cigars:

Look at the power of the cigarette
Lung cancer
This is what dying of lung cancer looks like

What is lung cancer?

Lung cancer is the leading cause of death from cancer among both males and females. It is the uncontrolled growth of abnormal cells in the lung, leading to the formation of a tumour.

Lung cancer symptoms include cough, chest pain, weight loss and sometimes the spitting up of blood or bloody mucus.

Treatment for lung cancer can involve surgery, chemotherapy, radiation or a combination of treatments.

How does smoking increase the risk of lung cancer?

Some of the chemicals in tobacco smoke cause, initiate or promote cancer. Footnote 13 Footnote 14  These chemicals cause genetic changes in cells of the lung, which can lead to the development of lung cancer.Footnote 1 

In addition, some of these chemicals inhibit and damage the normal cleaning process by which the lungs get rid of foreign and harmful particles. Smoke destroys an important cleansing layer in the lungs, which in turn causes a build-up of mucus. The result is "smokers' cough," an alternative method for the lungs to try to clean themselves.Footnote 15 

The benefits of quitting

When people stop smoking, the risk of lung cancer starts to decrease. Ten years after quitting, the risk of lung cancer is about one-third to one-half of that of a smoker.Footnote 15 

People who quit, even at middle age, avoid much of the future risk associated with smoking. The earlier someone quits, the greater the long-term benefit.Footnote 16 Footnote 17 

Quitting is more effective than other measures to avoid the development of lung cancer and other smoking-related diseases.

Need help to quit? Call the pan-Canadian quitline toll-free at 1-866-366-3667.

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