About PDQ

Physician Data Query (PDQ) is a comprehensive cancer database of the National Cancer Institute (NCI). The PDQ database contains a summary of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, complementary and alternative medicine. Most summaries come in two versions. Professional medical versions contain detailed information written in technical language. Patient versions are written in an easy-to-understand, non-technical language. Both versions contain accurate and up-to-date cancer information, and most versions are also available in Spanish.

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

This is the purpose of the Summary

This PDQ cancer information summary contains current information on the prevention and cessation of smoking and control of tobacco use. This is to inform and help patients, families and caregivers. It does not provide formal guidelines or recommendations for making health decisions.

Reviewers and Updates

Editorial Boards write summaries of PDQ cancer and update them. These councils are made up of experts in cancer treatment and other cancer-related specialties. Summaries are reviewed regularly and changes are made as new information becomes available. The date in each summary (“Updated”) is the date of the most recent change.

The information in this patient summary is taken from the professional health version, which is regularly reviewed by the PDQ Screening and Prevention Editorial Board and updated as necessary.

Clinical trial information

A clinical trial is a study that answers a scientific question as to whether one treatment is better than another. The tests are based on past research and laboratory studies. Each experiment answers certain scientific questions to find new and better ways to help cancer patients. During clinical trials, information is gathered about the effects of the new treatment and how well it works. If a clinical trial shows that the new treatment is better than the current one, the new treatment may be “standard.” Patients may want to consider participating in a clinical trial. Some clinical trials are only open to patients who have not started treatment.

Clinical trials can be found online on the NCI website. For more information, call the NCI’s Cancer Information Service (CIS) at 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. Unless the entire summary is provided and updated regularly, it cannot be defined as an NCI PDQ cancer information summary. However, the “NCI Breast Cancer Information Summary for Breast Cancer Prevention informs the user of the risks as follows: [include excerpt from the summary]. ”

The best way to refer to this PDQ summary is:

PDQ® Screening and Prevention Editorial Board. PDQ Smoking. Bethesda, MD: National Cancer Institute. Updated . Available here: https://www.cancer.gov/about-cancer/causes-prevention/risk/tobacco/quit-smoking-pdq. was obtained. [PMID: 26389305]

Images in this summary are used only in PDQ summaries with the permission of the author (s), artist and / or publisher. If you want to use the description in the PDQ summary and do not use the entire summary, you must obtain permission from the owner. Cannot be given by the National Cancer Institute. Information on the use of 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 3,000 scientific illustrations.


The information in these summaries should not be used to make decisions about insurance payments. More information on insurance coverage can be found on the Cancer.gov Cancer Care Management page.

Contact us

You can find more information about contacting us or getting help with the Cancer.gov website on our Contact Us page for help. Questions can also be sent to Cancer.gov via the website’s email.