What is 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

How Is Smoking Related to Cancer?

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

Men with prostate cancer who smoke may be more likely to die from these diseases than nonsmokers.5

Smokeless tobacco, such as chewing tobacco, also causes cancer, including cancers of the:7

How Can Smoking-Related Cancers Be Prevented?

Quitting smoking lowers the risks for cancers of the lung, mouth, throat, esophagus, and larynx.4,8

  • 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

Cancer Screening

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

How Is Cancer Treated?

The treatment for cancer depends on the type of cancer and the stage of the disease (how severe the cancer is and whether it has spread). Doctors may also consider the patient’s age and general health. Often, the goal of treatment is to cure the cancer. In other cases, the goal is to control the disease or to reduce symptoms for as long as possible. The treatment plan for a person may change over time.7

Most treatment plans include surgery, radiation therapy, or chemotherapy. Other plans involve biological therapy (a treatment that helps your immune system fight cancer).3

Some cancers respond best to a single type of treatment. Other cancers may respond best to a combination of treatments.3

For patients who get very high doses of chemotherapy or radiation therapy, a stem cell transplant, also known as a bone marrow transplant, may be recommended by their doctor. This is because high-dose therapies destroy both cancer cells and normal blood cells. A stem cell transplant can help the body to make healthy blood cells to replace the ones lost due to the cancer treatment. It’s a complicated procedure with many side effects and risks.12

Quitting smoking improves the outlook (the prognosis) for people with cancer. People who continue to smoke after diagnosis raise their risk for future cancers and death. They are more likely to die from cancer than nonsmokers and are more likely to develop a second (new) tobacco-related cancer.5,13


Colorectal Cancer and Ostomies

An ostomy (or stoma) is a surgical opening made to the body that allows waste to be eliminated from the body.10 Ostomies are used in treatment or management of cancer or other diseases.11 Ostomies are needed when the body’s normal opening is closed or altered as part of cancer treatment. An ostomy pouch is located around the opening to collect waste for removal. Ostomies are usually done during the first stages of surgical treatment to remove cancer.10 For colorectal cancer patients, a colostomy (surgical openings from the bowel or colon to the abdomen) can be a lifesaving surgery.10,11 An ostomy can be temporary or permanent.10,11 Temporary ostomies are used while the affected area of the body heals. Permanent ostomies are used when cancer has resulted in the removal of the entire colon or the end of it.10,11

Additional Resources

The United Ostomy Associations of America, Inc.external icon Web site focuses on the positive quality of life people can attain following ostomy surgery and provides information on a variety of topics, including:

  • Descriptions of ostomy terms
  • Frequently asked questions
  • Information about ostomy equipment
  • Tips for living with an ostomy
  • Resources, including:
    • Ways to connect with others who have had ostomy surgery
    • Medical information
    • Information for specific individuals (e.g., children, women)
    • Information about food and nutrition

Support Groups

To see if there is a support group in your area, visit United Ostomy Associations of America, Inc.’s support group Web siteexternal icon.


  1. National Cancer Institute. What Is Cancer? Defining Cancerexternal icon [last updated 2015 Feb 9; accessed 2015 Oct 19].
  2. Centers for Disease Control and Prevention. Cancer Prevention [last updated 2015 Jul 21; accessed 2015 Oct 19].
  3. National Institute on Aging. Cancer Facts for People Over 50external icon [last updated 2015 Jan 22; accessed 2015 Oct 19].
  4. U.S. Department of Health and Human Services. A Report of the Surgeon General. How Tobacco Smoke Causes Disease: What It Means to You. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2010 [accessed 2015 Oct 19].
  5. U.S. Department of Health and Human Services. Let’s Make the Next Generation Tobacco-Free: Your Guide to the 50th Anniversary Surgeon General’s Report on Smoking and Health. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2014 [accessed 2015 Oct 19].
  6. Centers for Disease Control and Prevention. Secondhand Smoke (SHS) Facts [last updated 2015 Aug 15; accessed 2015 Oct 19].
  7. World Health Organization International Agency for Research on Cancer. Smokeless Tobacco and Some Tobacco-Specific N-Nitrosaminespdf iconexternal icon [PDF – 3.19MB] [accessed 2015 Oct 19].
  8. Centers for Disease Control and Prevention. Poster: The Benefits of Quitting [accessed 2015 Oct 19].
  9. Centers for Disease Control and Prevention. Screen for Life: National Colorectal Cancer Action Campaign [last updated 2015 Jul 14; accessed 2015 Oct 19].
  10. American Cancer Society. Colostomy: A Guideexternal icon  [accessed 2015 Oct 19].
  11. National Institute of Diabetes and Digestive and Kidney Diseases. Ostomy Surgery of the Bowelexternal icon  [last updated 2014 Aug 13; accessed 2015 Oct 19].  
  12. Centers for Disease Control and Prevention. Diamond Blackfan Anemia (DBA): Stem Cell (Bone Marrow) Transplant [site no longer exists, Jun 6 2016].
  13. U.S. Department of Health and Human Services. The Health Consequences of Smoking—50 Years of Progress: A Report of the Surgeon General. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2014 [accessed 2015 Oct 19].
  14. U.S. Preventive Services Task Force. July 2015. Final Update Summary: Lung Cancer: Screeningexternal icon. [last updated: 2015 Jul; accessed 2016 Aug 12].