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Lung Cancer Prevention (PDQ®): Prevention - Health Professional Information [NCI] - Overview

Note: Separate PDQ summaries on Lung Cancer Screening; Small Cell Lung Cancer Treatment; Non-Small Cell Lung Cancer Treatment; and Cigarette Smoking: Health Risks and How to Quit are also available.

Who is at Risk?

Lung cancer risk is largely a function of older age combined with extensive cigarette smoking history. Lung cancer is more common in men than women and in those of lower socioeconomic status. Patterns of lung cancer according to demographic characteristics tend to be strongly correlated with historical patterns of cigarette smoking prevalence. An exception to this are the very high rates of lung cancer in African American men, a group whose very high lung cancer death rates are not explainable simply by historical smoking patterns.[1]

In nonsmokers, important lung cancer risk factors are exposure to secondhand smoke, radon exposure, and occupational exposure to lung carcinogens, such as asbestos. Cigarette smoking often interacts with these other factors. There are several examples, including radon exposure and asbestos exposure, in which the combined exposure to cigarette smoke plus another risk factor results in an increase in risk that is much greater than the sum of the risks associated with each factor alone.

Factors associated with increased risk of lung cancer

Cigarette smoking

Starting with the 1964 Surgeon General's Report and followed by each subsequent Surgeon General's Report that has included a review of the evidence on smoking and lung cancer, an enormous body of scientific evidence clearly documents that cigarette smoking causes lung cancer, and that cigarette smoking is the major cause of lung cancer.

Based on solid evidence, cigarette smoking causes lung cancer. The risks of lung cancer associated with cigarette smoking are dose-dependent and increase markedly according to the number of cigarettes smoked per day and the number of years smoked. On average, current smokers have approximately 20 times the risk of lung cancer compared with nonsmokers.

Magnitude of Effect: Increased risk, very large.

Study Design: Numerous prospective cohort and case-control studies, combined with quasi-experimental evidence showing population-level smoking prevalence predicts the population-level burden of lung cancer.
Internal Validity: Good.
Consistency: Good.
External Validity: Good.

Exposure to secondhand smoke

Based on solid evidence, exposure to secondhand smoke is an established cause of lung cancer.

Magnitude of Effect: Increased risk, small magnitude. Compared with nonsmokers not exposed to secondhand smoke, nonsmokers exposed to secondhand smoke have approximately 20% increased risk of lung cancer.

Study Design: Prospective cohort and case-control studies.
Internal Validity: Good.
Consistency: Good.
External Validity: Good.

Radon exposure

Based on solid evidence, exposure to radon increases lung cancer incidence and mortality.

Magnitude of Effect: Increased risk that follows a dose-response gradient, with small increases in risk for levels experienced in most at-risk homes to greater increases in risk for high-level exposures.

Study Design: Cohort and case-control studies.
Internal Validity: Fair.
Consistency: Good.
External Validity: Fair.
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WebMD Public Information from the National Cancer Institute

Last Updated: February 25, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
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