Lung cancer risk factors

Lung cancer Microchapters
Home
Patient Information
Overview
Historical Perspective
Classification
Pathophysiology
Causes
Differentiating Lung cancer from other Diseases
Epidemiology and Demographics
Risk Factors
Screening
Natural History, Complications and Prognosis
Diagnosis
Diagnostic study of choice
History and Symptoms
Physical Examination
Laboratory Findings
Electrocardiogram
X-ray
Echocardiography and Ultrasound
CT scan
MRI
Other Imaging Findings
Other Diagnostic Studies
Treatment
Medical Therapy
Surgery
Primary Prevention
Secondary Prevention
Cost-Effectiveness of Therapy
Future or Investigational Therapies
Case Studies
Case #1
Lung cancer risk factors On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
American Roentgen Ray Society Images of Lung cancer risk factors All Images X-rays Echo & Ultrasound CT Images MRI
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on Lung cancer risk factors
CDC on Lung cancer risk factors
Lung cancer risk factors in the news
Blogs on Lung cancer risk factors
Directions to Hospitals Treating Lung cancer
Risk calculators and risk factors for Lung cancer risk factors

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Kim-Son H. Nguyen, M.D., M.P.A., Beth Israel Deaconess Medical Center, Harvard Medical School, Boston MA, Cafer Zorkun, M.D., Ph.D. [2]

Overview

Smoking is the most important risk factor for the development of lung cancer. The risk of lung cancer is significantly higher among individuals who are active smokers, passive smokers, and even e-cigarette smokers. Similar risks are demonstrated for other forms of smoking (e.g. hookah smoking). Other risk factors include a positive family history for lung cancers and exposure to radon, asbestos, arsenic, and other chemical carcinogens.

Common Risk Factors

The following may increase one's risk of lung cancer:

• Smoking
• Second-hand smoke
• Family history of lung cancer
• High levels of air pollution
• Radiation therapy to the chest
• Radon gas
• Asbestos
• High levels of arsenic in drinking water
• Occupational exposure to chemical carcinogens
• Previous lung disease
• Indoor burning of coal
• Weakened immune system
• Lupus

Smoking

• Cigarette smoking is the leading cause of lung cancer.
• Both active and passive smoking are associated with increased risk of lung cancer.
• The risk of lung cancer is associated with increased quantity of cigarette smoking as well as increased duration of smoking.
• There is no evidence that smoking low-tar cigarettes lowers the risk (however lung cancer has occurred in people who have never smoked).
• The more cigarettes you smoke per day and the earlier you started smoking, the greater your risk of lung cancer.
• Recently introduced e-cigarrettes, which were thought to be risk-free were recently demonstrated to be also associated with a significantly increased risk of lung cancer due to the presence of formaldehyde.
• In the United States, smoking is estimated to account for 87% of lung cancer cases (90% in men and 85% in women).*There is approximately a 20 year lag period between smoking and death due to lung cancer (in men). Shown below is an image depicting the correlation between smoking and lung cancer.

The incidence of lung cancer is highly correlated with smoking. Source: NIH.

Second-hand smoke

• Second-hand smoke is what smokers exhale and what rises from a burning cigarette, pipe or cigar. It is also called environmental tobacco smoke (ETS), or involuntary or passive smoking.

• Second-hand smoke contains the same chemicals as smoke that is actively inhaled. People exposed to second-hand smoke have an increased risk of lung cancer. Second-hand smoke is a main risk factor for lung cancer among non-smokers. No amount of exposure to second-hand smoke is safe.

Air Pollution

• Emissions from automobiles, factories and power plants are thought to pose potential risks.

• Researchers have shown that individual components of outdoor air pollution cause cancer. These components include diesel engine exhaust, benzene, particulate matter and some polycyclic aromatic hydrocarbons (PAHs).

Family History of Lung Cancer

• Family history of lung cancer may increase the risk of lung cancer. However, a positive family history is not as important as a risk factor compared to smoking.

Radiation Therapy to the Chest

• A history of radiation therapy to the chest increases the risk of lung cancer due to the development of cellular damage and DNA mutations.

Radon Exposure

• Radon gas (home basements) > 4 pCi/L
• In USA high concentrations of radon are reported in Iowa.

Asbestos Exposure

• Asbestos particles often reside in the lungs and cause a state of chronic inflammation that prediposes to the development of lung cancer.

Exposure to Other Chemical Carcinogens

• Arsenic in drinking water
• Uranium
• Beryllium
• Vinyl chloride
• Nickel chromates
• Coal products
• Mustard gas
• Chloromethyl ethers

Less Common Risk Factors

• Smoking marijuana
• Indoor burning of wood
• High-temperature frying
• Diet
• Physical inactivity
• Occupational exposure to certain chemicals
• Removal of both ovaries