Cancers Caused by Smoking: Full List for Canada

Cancer is one of the diseases Health Canada ties to tobacco, and the list is longer than most people expect. This page puts the cancers in one table, with the share of cases Health Canada attributes to smoking wherever it gives one. Where a page gives no figure, the table says so instead of guessing. Every figure comes from Health Canada’s own tobacco pages, read on November 13, 2026.

The list at a glance

Cancer	Share attributed to smoking	What Health Canada says
Lung	72% of cases (another page says 85% of new cases)	Smoking is the main cause
Mouth and throat (oral)	About 40% of new cases in 2015	Smokers have roughly 5 to 10 times the risk of people who never smoked
Bladder	About half of diagnosed cases	Smokers can have up to six times the risk
Stomach	About 20% of cases in 2015	Risk rises with years smoked and cigarettes per day
Cervical	About 26% of cases in 2015	Smokers are twice as likely to develop certain subtypes
Kidney	About 17% of cases in 2015	Risk rises with the number of cigarettes smoked
Larynx, esophagus, pancreas, leukemia	No figure given	Named as linked to smoking

Lung cancer

Health Canada estimates that 72% of lung cancer cases in Canada are caused by smoking. Its “Smoking and your body” page gives 85% of new cases instead. The two pages do not explain the gap, so read the figure as “most” rather than a precise number. For what smoking does inside the lungs, see what smoker’s lungs look like, and for warning signs see lung cancer symptoms.

Mouth and throat cancers

Health Canada says about 40% of new oral cancer cases in 2015 were due to smoking. Drinking alcohol adds to the risk. The “Smoking and your body” page also names the voice box and the esophagus, without percentages. Risk for oral cancer starts to fall within five years of quitting and, after 20 or more years, matches that of a person who never smoked.

Bladder, kidney and stomach cancers

Smoke chemicals pass into the urine, and Health Canada says they can stay there for up to 18 hours, which can change bladder cells. A few years after quitting, bladder cancer risk drops by about half. For kidney cancer, risk falls by up to 25% after 15 or more years without smoking. Stomach cancer risk is similar to that of a never-smoker about ten years after quitting.

Cervical cancer

Health Canada says smoking exposes the cervix to carcinogens and weakens defences against HPV infection. After 20 or more years smoke-free, the page says risk is the same as for someone who has never smoked.

Leukemia and pancreatic cancer

Health Canada says smoking tobacco is a contributing cause of leukemia and of pancreatic cancer. The page gives no percentages for either.

Smoking after a diagnosis

The bladder, oral, cervical and kidney pages each say that continuing to smoke after a diagnosis can lower survival chances. The oral, bladder and cervical pages add that it raises the risk of other smoking-related cancers, such as lung cancer. For the wider picture of harm, read cigarette side effects, the broader smoking and cancer page and smoking statistics for Canada. If you are eligible for screening, the lung screening eligibility checker explains the criteria.

This is general information, not advice for your situation. A doctor, nurse practitioner or pharmacist can talk through your own risk, or you can call 811.

What we could not confirm

We did not confirm a Canadian share for larynx, esophagus, pancreatic, liver, colorectal cancer or leukemia from the pages above. The Canadian Cancer Society pages returned an access error when we tried to read them, so nothing here relies on them. Provincial figures were not checked.