National Cancer Institute


Expert-reviewed information summary about the influence of continued smoking on cancer treatment and risk of second cancers. Interventions to encourage smoking cessation are also discussed.

Expert-reviewed information summary about the influence of continued smoking on cancer treatment and risk of second cancers. Interventions to encourage smoking cessation are also discussed.

Smoking in Cancer Care

Overview

This summary is about cancer patients who smoke, why it is important to stop smoking, and ways to get help. It includes information on the following:

  • Risks of smoking in cancer patients, including second cancers.
  • Counseling to help cancer patients quit smoking.
  • Treatment with drugs to help cancer patients quit smoking.

Smoking and Cancer Risk

Key Points for this Section

  • Smoking increases the risk of cancer.
  • Lung cancer and other types of cancers are linked to tobacco use.

Smoking increases the risk of cancer.

Smoking is the leading cause of cancer in the United States. Lung cancer is the leading cause of cancer death in both men and women in the United States. If you smoke, your risk of cancer can be up to 10 times higher than it is for a person who never smoked.

Smoking increases cancer risk by:

Your risk depends on how much and how long you have smoked.

Lung cancer and other types of cancers are linked to tobacco use.

Cancer risks linked to tobacco use include the following:

  • Lung cancer and head and neck cancers are linked to tobacco use.
  • People who started smoking before age 30 and have been smoking for a long time have a high risk of colorectal cancer.
  • In smokers diagnosed with cancer, the cancer is more likely to have already spread.

See the following for more information:

Risks of Smoking During Cancer Treatment

Key Points for this Section

  • Quitting smoking is helpful after cancer is diagnosed.
  • If you keep smoking, you may not respond well to treatment.
  • Cancer patients who keep smoking increase their risk of having a second cancer.

Quitting smoking is helpful after cancer is diagnosed.

Studies have found that smokers who quit are more likely to recover from cancer than are patients who continue to smoke.

If you keep smoking, you may not respond well to treatment.

If you continue to smoke during cancer treatment, you may not respond to treatment as well as patients who do not smoke. Also, you may have worse side effects from treatment. For example, patients who are given radiation therapy for laryngeal cancer are less likely to get their voice back to normal if they keep smoking.

Wounds from surgery heal more slowly in patients who keep smoking. Studies have found that prostate cancer patients who keep smoking have a higher risk of the cancer coming back, and of death from prostate cancer. However, prostate cancer patients who quit smoking for 10 years or longer lower their risk of death to about the same as nonsmokers.

Cancer patients who keep smoking increase their risk of having a second cancer.

You have a higher risk of a second cancer if you keep smoking, whether you have a cancer that is smoking-related or not smoking-related. The risk of a second cancer may last for up to 20 years, even if the first cancer has been treated and is in remission (signs and symptoms of cancer have disappeared). Patients with oral and pharyngeal cancer who smoke have a high risk of a second cancer, but the risk is much less after 5 years of not smoking.

Counseling to Help You Quit Smoking

Key Points for this Section

  • Counseling may make it easier for you to quit smoking.
  • It may take more than one try to quit smoking completely.
  • You can find help online.

Counseling may make it easier for you to quit smoking.

It is not easy to quit smoking and research has shown that people are more likely to quit if they have help. Mood changes are common in cancer patients and in people who smoke or are trying to quit smoking. Talk with your doctor if you have feelings of depression. Your doctor can offer counseling or other ways to help you quit smoking and treat depression when needed.

Not all smokers are motivated to quit. If you are not motivated to quit smoking, your doctor may be able to help you become motivated.

Your doctor or other health care professional may take the following steps to help you quit:

  • Ask you about your smoking habits at every visit.
  • Advise you to quit smoking.
  • Help you with a plan to quit smoking by:
    • Setting a date to quit smoking.
    • Giving you self-help materials.
    • Recommending drug treatment.
  • Plan follow-up visits with you.

It may take more than one try to quit smoking completely.

When you first quit smoking, it is common to start again. There will be many stressful times that will make you want to smoke. Counseling can help you find ways to handle the stress other than by smoking. It may take more than a year to quit smoking completely, even when you are motivated.

You can find help online.

The following websites may be helpful:

Treatment With Medicine to Help You Quit Smoking

Key Points for this Section

  • There are different ways to stop smoking.
  • Nicotine replacement therapy may help you quit smoking.
  • Other medicines may also help you quit smoking.

There are different ways to stop smoking.

Different ways to stop smoking work for different patients. Some smokers can quit with the help of counseling, while others may need medicines to help them quit.

Nicotine replacement therapy may help you quit smoking.

When you are trying to quit smoking, nicotine replacement therapy may help you with withdrawal symptoms, such as:

  • Feeling depressed.
  • Feeling nervous.
  • Having trouble thinking clearly.
  • Having trouble sleeping.

Nicotine replacement products include the following:

Talk with your doctor before you start any form of treatment. Nicotine replacement products can cause problems in some people, especially:

Other medicines may also help you quit smoking.

The following drugs, which do not have nicotine in them, are used to help people quit smoking:

  • Varenicline (also called Chantix). Varenicline is a drug approved by the Food and Drug Administration (FDA) that acts the same way nicotine acts in the brain. In June 2011, the FDA warned that varenicline may increase the risk of heart problems in patients with cardiovascular disease. Other side effects of varenicline include the following:
  • Bupropion (also called Zyban). Bupropion is an antidepressant approved by the FDA to help people quit smoking.
  • Fluoxetine (also called Prozac). Fluoxetine is an antidepressant and studies have shown that it can help people quit smoking.

These medicines lessen nicotine craving and nicotine withdrawal symptoms.

Fluoxetine causes an increased risk of suicide in adults younger than 25 years. In July 2009, the FDA warned that varenicline and bupropion may cause depression, suicide, and other mental health changes in patients who take them. These changes include:

  • Extreme mood changes.
  • Psychosis (not being able to recognize what is real or relate to others).
  • Hallucinations (a sight, sound, smell, taste, or touch that the patient believes to be real but is not real).
  • Paranoia (an extreme fear or distrust of others).
  • Delusions (believing something that is not true).
  • Homicidal thoughts (thoughts about killing others).
  • Hostility (having or showing unfriendly feelings).
  • Agitation (inability to relax or be still).
  • Anxiety (feelings of fear, dread, and uneasiness that may be a reaction to stress).
  • Panic (sudden extreme anxiety or fear that may cause irrational thoughts or actions).
  • Suicidal thoughts and attempted suicide.

These mental health changes may occur in patients with or without a history of psychiatric illness and it is not known if nicotine withdrawal is a part of this. (See the Depression and Suicide section in the PDQ summary on Pediatric Supportive Care.)

All patients taking these medicines, especially those with a history of psychiatric illness, should be followed closely by a doctor.

The FDA recommends that the important health benefits of quitting smoking be weighed against the small but serious risk of problems with the use of these drugs.

To Learn More About Smoking in Cancer Care

For more information about smoking in cancer care, see the following:

About This PDQ Summary

About PDQ

Physician Data Query (PDQ) is the National Cancer Institute's (NCI's) comprehensive cancer information database. The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries come in two versions. The health professional versions have detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions have cancer information that is accurate and up to date and most versions are also available in Spanish.

PDQ is a service of the NCI. The NCI is part of the National Institutes of Health (NIH). NIH is the federal government’s center of biomedical research. The PDQ summaries are based on an independent review of the medical literature. They are not policy statements of the NCI or the NIH.

Purpose of This Summary

This PDQ cancer information summary has current information about the risks of continued smoking in cancer patients and ways to stop. It is meant to inform and help patients, families, and caregivers. It does not give formal guidelines or recommendations for making decisions about health care.

Reviewers and Updates

Editorial Boards write the PDQ cancer information summaries and keep them up to date. These Boards are made up of experts in cancer treatment and other specialties related to cancer. The summaries are reviewed regularly and changes are made when there is new information. The date on each summary ("Date Last Modified") is the date of the most recent change.

The information in this patient summary was taken from the health professional version, which is reviewed regularly and updated as needed, by the PDQ Supportive and Palliative Care Editorial Board.

Clinical Trial Information

A clinical trial is a study to answer a scientific question, such as whether one treatment is better than another. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients. During treatment clinical trials, information is collected about the effects of a new treatment and how well it works. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.

Clinical trials are listed in PDQ and can be found online at NCI's website. Many cancer doctors who take part in clinical trials are also listed in PDQ. For more information, call the Cancer Information Service 1-800-4-CANCER (1-800-422-6237).

Permission to Use This Summary

PDQ is a registered trademark. The content of PDQ documents can be used freely as text. It cannot be identified as an NCI PDQ cancer information summary unless the whole summary is shown and it is updated regularly. However, a user would be allowed to write a sentence such as “NCI’s PDQ cancer information summary about breast cancer prevention states the risks in the following way: [include excerpt from the summary].”

The best way to cite this PDQ summary is:

PDQ® Supportive and Palliative Care Editorial Board. PDQ Smoking in Cancer Care. Bethesda, MD: National Cancer Institute. Updated . Available at: http://www.cancer.gov/about-cancer/causes-prevention/risk/tobacco/smoking-cessation-pdq. Accessed . [PMID: 26389200]

Images in this summary are used with permission of the author(s), artist, and/or publisher for use in the PDQ summaries only. If you want to use an image from a PDQ summary and you are not using the whole summary, you must get permission from the owner. It cannot be given by the National Cancer Institute. Information about using the images in this summary, along with many other images related to cancer can be found in Visuals Online. Visuals Online is a collection of more than 2,000 scientific images.

Disclaimer

The information in these summaries should not be used to make decisions about insurance reimbursement. More information on insurance coverage is available on Cancer.gov on the Managing Cancer Care page.

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