Lung Cancer

Causes and Risk Factors

Tobacco Products and Cancer

Using tobacco products has been shown to cause cancer. In fact, smoking tobacco, using smokeless tobacco, and being exposed regularly to secondhand tobacco smoke are responsible for a large number of cancer deaths in the U.S. each year.

Cigarette Smoking Causes Lung Cancer

Cigarette smoking is the number one cause of lung cancer. Scientists have reported widely on the link between cancer and smoking since the 1960s. Since then, study after study has provided more proof that cigarette smoking is the primary cause of lung cancer.

Before cigarette smoking became popular in the early part of the 20th century, doctors rarely, if ever, saw patients with lung cancer. But today, lung cancer is the leading cause of death by cancer. Over 85 percent of people with lung cancer developed it because they smoked cigarettes.

If You Smoke

If you smoke cigarettes, you are at much higher risk for lung cancer than a person who has never smoked. The risk of dying from lung cancer is 23 times higher for men who smoke and 13 times higher for women who smoke than for people who have never smoked. Lung cancer can affect young and old alike.

Stopping smoking greatly reduces your risk for developing lung cancer. After you stop, your risk levels off. Ten years after the last cigarette, the risk of dying from lung cancer drops by 50 percent -- which does not mean, however, that risk is eliminated.

Smoking cigars and pipes also puts you at risk for lung cancer. Cigar and pipe smokers have a higher risk of lung cancer than nonsmokers. Even cigar and pipe smokers who do not inhale are at increased risk for lung, mouth, and other types of cancer.

The likelihood that a smoker will develop lung cancer is related to the age smoking began; how long the person smoked; the number of cigarettes, pipes, or cigars smoked per day; and how deeply the smoker inhaled.

Other Factors That Increase Your Risk

It's Never Too Late To Quit

Researchers continue to study the causes of lung cancer and to search for ways to prevent it. We already know that the best way to prevent lung cancer is to quit or never start smoking. The sooner a person quits smoking the better. Even if you have been smoking for many years, it's never too late to benefit from quitting.

Each U.S. state and territory has a free quitline to provide you with information and resources to help you quit smoking. To reach the quitline in your area, dial toll-free, 1-800-QUIT-NOW.