Skip to content

Cancer Health Center

Font Size

Cigarette Smoking: Health Risks and How to Quit (PDQ®): Prevention - Health Professional Information [NCI] - Summary of Evidence

Note: A separate PDQ summary on Levels of Evidence for Cancer Screening and Prevention Studies is also available.

The cancer prevention summaries in PDQ refer to cancer prevention, defined as a reduction in the incidence of cancer. The PDQ includes summaries generally classified by histological type of cancer, especially when there are known risk factors for the specific types of cancer. This summary addresses a specific risk factor, tobacco use, which is associated with a large number of different cancers (and other chronic diseases) and unequivocally contains human carcinogens.[1] The focus of this summary is on clinical interventions by health professionals that decrease the use of tobacco.

Recommended Related to Cancer

Get More Information From NCI

Call 1-800-4-CANCER For more information, U.S. residents may call the National Cancer Institute's (NCI's) Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 8:00 a.m. to 8:00 p.m., Eastern Time. A trained Cancer Information Specialist is available to answer your questions. Chat online The NCI's LiveHelp® online chat service provides Internet users with the ability to chat online with an Information Specialist. The...

Read the Get More Information From NCI article > >

Effects of Smoking Cessation

Based on solid evidence, cigarette smoking causes cancers of the lung, oral cavity and pharynx, larynx, esophagus, bladder, kidney, pancreas, stomach, uterine cervix, and acute myeloid leukemia.[2] Smoking avoidance and smoking cessation result in decreased incidence and mortality from cancer.

Description of the Evidence

  • Study Design: Evidence obtained from a randomized controlled trial.
  • Internal Validity: Good.
  • Consistency: Good.
  • Magnitude of Effects on Health Outcomes: The relative risk (RR) of several cancers is much greater in cigarette smokers compared with nonsmokers (depending on the anatomical site of the cancer and the intensity and duration of smoking, the RR can range from twofold to tenfold or greater in smoking populations). A reduction of 15% is seen in the RR of all-cause mortality in heavy smokers subjected to intensive clinical cessation interventions.
  • External Validity: Good.

Counseling and Smoking Cessation

Based on solid evidence, counseling by a health professional improves smoking cessation rates.

Description of the Evidence

  • Study Design: Evidence obtained from randomized controlled trials.
  • Internal Validity: Good.
  • Consistency: Good.
  • Magnitude of Effects on Health Outcomes: Counseling improves cessation rates (odds ratio [OR], 1.56; 95% confidence interval [CI], 1.32–1.84).[3,4]
  • External Validity: Good.

Physician Advice and Smoking Cessation

Based on solid evidence, simple advice from a physician to stop smoking improves smoking cessation rates.

  • Study Design: Evidence obtained from randomized controlled trials.
  • Internal Validity: Good.
  • Consistency: Good.
  • Magnitude of Effects on Health Outcomes: Physician advice improves cessation rates (relative risk [RR], 1.66; 95% CI, 1.42–1.94).[3]
  • External Validity: Good.
    1|2
    Next Article:

    Today on WebMD

    Colorectal cancer cells
    A common one in both men and women.
    Lung cancer xray
    See it in pictures, plus read the facts.
     
    sauteed cherry tomatoes
    Fight cancer one plate at a time.
    Ovarian cancer illustration
    Do you know the symptoms?
     
    Jennifer Goodman Linn self-portrait
    Blog
    what is your cancer risk
    HEALTH CHECK
     
    colorectal cancer treatment advances
    Video
    breast cancer overview slideshow
    SLIDESHOW
     
    prostate cancer overview
    SLIDESHOW
    lung cancer overview slideshow
    SLIDESHOW
     
    ovarian cancer overview slideshow
    SLIDESHOW
    Actor Michael Douglas
    Article