Smoking and Cancer Risk

Medically Reviewed by Jennifer Robinson, MD on September 14, 2022
2 min read

Smoking cigarettes causes about 3 out of every 10 cancer deaths in the U.S. As many as 80% of people who die of lung cancer used tobacco.

But the toxins and chemicals from cigarette smoke can lead to cancers almost anywhere in your body. Among them are some of the most common types of tumors.

There are more than 100 kinds of cancers. The U.S. Surgeon General has identified smoking as a cause for these 12 cancers:

Tobacco smoke has more than 7,000 chemicals. Many, such as arsenic, radioactive polonium-20, and mercury, are toxic. Doctors know of at least 70 things, called carcinogens, that cause cancer in people or animals.

You also can get cancer from smokeless tobacco products. They include dipping and chewing tobacco. Breathing other people’s smoke secondhand can cause cancer. For example, those bystanders are up to 30% more likely to get lung cancer than someone who’s not exposed to secondhand smoke.

Cancer can happen when carcinogens damage your DNA and cause your cells to grow and divide abnormally. The cancerous growth then may invade healthy tissue and spread throughout your body.

The toxins from smoking also weaken your body’s immune response and make it harder to fight off cancer.

There is no safe way to use tobacco. And even brief exposure to smoking can raise your risk for cancers.

Your chances of cancer rise with the number of cigarettes you smoke each day and how many years you do it. The reverse is true, too. The less you smoke and the sooner you quit, the lower your odds of getting any of the 12 cancers linked to smoking.

Five years after you quit, your odds for mouth, throat, esophageal, and bladder cancer will drop by half. Your odds of getting cervical cancer will fall to the same level as someone who doesn’t smoke.

If you go 20 years without smoking, your risk of getting cancer of the mouth, throat, voice box, or pancreas will be about the same as if you’d never smoked.