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Tobacco use causes cancer

What you may have heard

Tobacco use is a leading cause of cancer and cancer death. It is also the biggest preventable cause of cancer.

What science tells us

All tobacco products, including cigarettes, cigars, pipe tobacco, chewing tobacco, and snuff contain poisonous substances, cancer-causing agents, and nicotine (a highly addictive substance).

Cigarettes are the most common form of tobacco used and are responsible for about 90% of all lung cancers, according to the American Lung Association (Johns Hopkins).

Epidemiological Evidence

Both people who smoke and people who inhale secondhand smoke have an increased risk of cancer, because tobacco has chemicals that cause DNA damage. Tobacco use causes many types of cancer:  lung, larynx (voice box), esophagus, throat, bladder, kidney, liver, stomach, pancreas, colon, rectum, and acute myeloid leukemia (cancer of the blood and bone marrow) (NCI).

Cigars and pipes are often branded as a less harmful way to smoke tobacco; however, cigar and pipe smokers are at increased risk for cancer of the oral cavity, esophagus, voice box, and lungs. Pipe smokers are also at increased risk for lip cancers because of where the pipestem rests (Johns Hopkins).

People who use smokeless tobacco (snuff or chewing tobacco, which is placed between the cheek and the gum) have an increased risk of cancers of the mouth, esophagus, and pancreas (Johns Hopkins). Over 28 cancer-causing chemicals have been found in smokeless tobacco.

Laboratory Evidence/ Supportive Evidence

Animal models have also confirmed that tobacco smoking not only increases the risk of lung cancer, but lifetime exposure to tobacco smoke also increases the risk for lung cancer (Hecht). 

IARC Carcinogen Classification: Group 1 (carcinogenic to humans)

How to reduce your risk

There is no safe level of tobacco use. People who use any type of tobacco product are strongly urged to quit. Scientific evidence shows that people who quit smoking, regardless of their age, have large gains in life expectancy compared to people who continue to smoke (NCI). Also, quitting smoking when diagnosed with cancer reduces the risk of cancer death.

If you are having trouble quitting on your own, get help from your doctor or from other support services, such as your state Quitline (1-800-QUIT-NOW) or the American Cancer Society (1-800-ACS-2345). The American Cancer Society recommends picking a stress-free time to quit, asking for support and encouragement from family and friends, doing some exercise or activity each day to relieve stress, joining a stop-smoking program, and talking with your healthcare provider about medicines that may help you quit (Johns Hopkins).

Bottom line

Tobacco use does increase risk of cancer. Avoid smoking and smoke exposure. Resources are available to help quit smoking.

National Cancer Institute (NCI): Tobacco
Centers for Disease Control and Prevention (CDC): Cancer and tobacco use
Johns Hopkins: Oral cancer and tobacco
Cancer Research UK: Cancer and smoking
National Cancer Institute (NCI): Harms of smoking and benefits of quitting


June 24, 2021
Verified/updated: August 22, 2022