Smoking and Cancer
Cancer refers to diseases in which abnormal cells divide out of control and are able to invade other tissues. Cancer cells can spread to other parts of the body through the blood and lymph systems, which help the body get rid of toxins.1,2
There are more than 100 different types of cancer. Most cancers are named for the organ or type of cell in which they start—for example, lung cancer begins in the lung and laryngeal cancer begins in the larynx (voice box).1
Symptoms can include:3
- A thickening or lump in any part of the body
- Weight loss or gain with no known reason
- A sore that does not heal
- Hoarseness or a cough that does not go away
- A hard time swallowing
- Discomfort after eating
- Changes in bowel or bladder habits
- Unusual bleeding or discharge
- Feeling weak or very tired
Smoking can cause cancer and then block your body from fighting it:4
- Poisons in cigarette smoke can weaken the body’s immune system, making it harder to kill cancer cells. When this happens, cancer cells keep growing without being stopped.
- Poisons in tobacco smoke can damage or change a cell’s DNA. DNA is the cell’s “instruction manual” that controls a cell’s normal growth and function. When DNA is damaged, a cell can begin growing out of control and create a cancer tumor.
Doctors have known for years that smoking causes most lung cancers. It’s still true today, when nearly 9 out of 10 lung cancers are caused by smoking cigarettes. In fact, smokers have a greater risk for lung cancer today than they did in 1964, even though they smoke fewer cigarettes. One reason may be changes in how cigarettes are made and what chemicals they contain.5
Treatments are getting better for lung cancer, but it still kills more men and women than any other type of cancer. In the United States, more than 7,300 nonsmokers die each year from lung cancer caused by secondhand smoke.6 Secondhand smoke is the combination of smoke from the burning end of a cigarette and the smoke breathed out by smokers.
Smoking can cause cancer almost anywhere in your body, including the:5
- Blood (acute myeloid leukemia)
- Colon and rectum
- Kidney and renal pelvis
- Mouth and throat
- Trachea, lung. and bronchus
Smokeless tobacco, such as chewing tobacco, also causes cancer, including cancers of the:7
- Within 5 years of quitting, your chance of getting cancer of the mouth, throat, esophagus, and bladder is cut in half.4
- Ten years after you quit smoking, your risk of dying from lung cancer drops by half.4
If nobody smoked, one of every three cancer deaths in the United States would not happen.4
Screening for Cervical and Colorectal Cancers
Research shows that screening for cervical and colorectal cancers, as recommended, helps prevent these diseases. Screening for cervical and colorectal cancers helps find these diseases at an early, and often highly treatable, stage. CDC offers free or low-cost cervical cancer screening nationwide.2
Health care reform through the Affordable Care Act increases access to cervical and colorectal cancer screening through expanded insurance coverage and eliminating cost-sharing. In addition, CDC’s Screen for Life: National Colorectal Cancer Action Campaign informs men and women aged 50 years and older about the importance of having regular colorectal cancer screening tests.9
Screening for Lung Cancer
People who have smoked for many years may consider screening for lung cancer with low-dose computed tomography (LDCT). Talk to your doctor about lung cancer screening and the possible benefits and risks. Lung cancer screening is not a substitute for quitting smoking.
The U.S. Preventive Services Task Force recommends annual screening for lung cancer with low-dose computed tomography in adults aged 55 to 80 years who have a 30 pack-year smoking history and currently smoke or have quit within the past 15 years. Screening should be discontinued once a person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery.14
The treatment 