The pathophysiology of lung cancer refers to the functional changes that cause, result from, or are otherwise associated with the disease. In the case of lung cancer, the changes occur in the lungs. As the disease progresses, other areas of the body may be involved as well.
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Types of Lung Cancer
The two main types oflung cancerare small cell lung cancer andnon-small cell lung cancer. Non-small cell lung cancers make up about 80% to 85% of all lung cancer cases and include:
Small cell lung cancers make up about 10% to 15% of all lung cancer cases and are sometimes called oat cell cancer.
What does pathophysiology mean?
Causes
Other exposures that can lead to lung cancer are secondhand smoke, radon, air pollution, and asbestos. Some workplace exposures like diesel exhaust and other chemicals can also raise the risk of lung cancer.
First-Hand vs. Second-Hand Smoke ExposureLung cancers in those who have never smoked tend to cause different lung changes than the cancers that are present in people who have smoked. Those who have never smoked tend to develop lung cancer at a younger age and may have certain gene changes.
First-Hand vs. Second-Hand Smoke Exposure
Lung cancers in those who have never smoked tend to cause different lung changes than the cancers that are present in people who have smoked. Those who have never smoked tend to develop lung cancer at a younger age and may have certain gene changes.
Inherited Gene Mutation
It’s possible to inherit a DNA mutation from one or both of your parents. It’s important to note that inherited mutations alone usually do not lead to cancer. They simply increase our risk. People who inherit a mutation in chromosome 6 are more likely to develop lung cancer even if they do not smoke tobacco.
Other inherited mutations include people whose bodies cannot break down some of the chemicals found in cigarettes or who cannot repair damaged DNA.
Some forms of non-small cell lung cancer cause the epidermal growth factor receptor (EGFR)gene to produce too much EGFR protein in the body. This is often seen in individuals withadenocarcinomawho do not have a history of smoking.
Acquired Gene Mutation
While it is possible to inherit a gene mutation that can lead to cancer, most gene mutations are acquired over a lifetime. These mutations often occur due to environmental exposures and cause changes in the DNA of lung cells. These changes can then lead to abnormal cell growth and possibly cancer.
DNA is a chemical in our cells that makes up our genes. We inherit DNA from both of our parents, and it can influence our risk of developing several chronic diseases, including cancer. The genes involved in cancer are:
Gene mutations that may lead to lung cancer include:
Besides mutations, gene alterations—like translocations, for example—may also increase the risk of lung cancer. Examples of common translocations include:
Besides gene mutations and translocations, non-random chromosomal abnormalities associated with lung cancer have been described on chromosome 3 and chromosome 6.
A 2020 meta-analysis found that there was no link between mutations in theBRCA1orBRCA2genes and lung cancer.
Tobacco Smoke
Exposure to tobacco smoke is the leading risk factor for developing lung cancer. Smoking a cigar or pipe has been found to be almost as likely to cause lung cancer as cigarette smoking.
Secondhand smoke can raise your risk of developing lung cancer. It’s estimated that secondhand smoke leads to 7,000 deaths from lung cancer each year.
Radon
Radonis a naturally occurring radioactive gas that you cannot see, smell, or taste. It’s believed to be the second leading cause of lung cancer in people who do not smoke.Radon exposure usually happens inside the home. Breathing in small amounts every day raises your risk for lung cancer over time.
Radon exists naturally in the soil and comes up into buildings through small cracks or gaps in the floor. It’s estimated that one in every 15 homes in the United States is at risk for radon exposure.If you’re unsure if your home is at risk, you can purchase a test kit from a hardware store to test the levels.
Asbestos
Asbestosis a group of naturally occurring minerals that are likely found in mines, mills, textile plants, shipyards, and places where people work with insulation. Exposure to these minerals at work raises your risk for lung cancer, especially if you also smoke.
Exposure to asbestos also raises your risk formesothelioma, a type of cancer that starts in the lining surrounding the lungs, known as the pleura. Asbestos exposure usually occurs at work. Other workplace exposures that have been linked to lung cancer include:
History of Radiation to the Lungs
Receiving radiation to your chest is a risk factor for lung cancer, especially if you also smoke. People who may have a history of chest radiation include those treated forHodgkin lymphomaor breast cancer.
Air Pollution
It’s estimated thatair pollutionis to blame for about 5% of all lung cancer deaths worldwide.This risk factor is difficult to address because we as individuals usually do not have control over the quality of the air we breathe.
History of Lung Cancer
Having a personal or family history of lung cancer raises your risk of developing the disease. Talk with your doctor if lung cancer runs in your family, especially if you experience other risk factors.
Cancer research is constantly evolving, and we may learn of additional causes in the future. The following substances may raise your risk for lung cancer, but there is not yet enough evidence to be sure:
Symptoms of Lung Cancer
Lung cancer does not always cause symptoms in the early stages. Often,lung cancer symptomspresent once the cancer has begun to spread. As soon as you develop any signs or symptoms of lung cancer, it’s important to see your doctor right away.
The most common signs and symptoms of lung cancer include:
Summary
The pathophysiology of lung cancer refers to the physical changes in the body that lead to lung cancer. The leading cause of lung cancer is exposure to tobacco smoke.
Other possible causes include radon, asbestos, radiation, and air pollution. Gene mutations, either inherited or acquired, may raise your risk of developing lung cancer. Signs and symptoms include a persistent cough, coughing up blood, chest pain, and loss of appetite.
7 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Cancer Society.Types of lung cancer.Stoyanov GS, Naskovska G, Lyutfi E, Kirneva R, Bratoeva K.In search of the ninth discipline: The history of pathophysiology, with an emphasis on pathophysiology in varna, Bulgaria-celebrating 100 years of pathophysiology in Bulgaria.Cureus. 2018;10(4):e2404. doi:10.7759/cureus.2404American Cancer Society.Lung cancer causes.Lee YC, Lee YC, Li CY, Lee YL, Chen BL.BRCA1andBRCA2gene mutations and lung cancer sisk: a meta-analysis.Medicina (Kaunas). 2020;56(5):212. doi:10.3390/medicina56050212American Cancer Society.Lung cancer risk factors.American Lung Association.Lung cancer causes & risk factors.American Cancer Society.Lung cancer signs & symptoms.
7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Cancer Society.Types of lung cancer.Stoyanov GS, Naskovska G, Lyutfi E, Kirneva R, Bratoeva K.In search of the ninth discipline: The history of pathophysiology, with an emphasis on pathophysiology in varna, Bulgaria-celebrating 100 years of pathophysiology in Bulgaria.Cureus. 2018;10(4):e2404. doi:10.7759/cureus.2404American Cancer Society.Lung cancer causes.Lee YC, Lee YC, Li CY, Lee YL, Chen BL.BRCA1andBRCA2gene mutations and lung cancer sisk: a meta-analysis.Medicina (Kaunas). 2020;56(5):212. doi:10.3390/medicina56050212American Cancer Society.Lung cancer risk factors.American Lung Association.Lung cancer causes & risk factors.American Cancer Society.Lung cancer signs & symptoms.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
American Cancer Society.Types of lung cancer.Stoyanov GS, Naskovska G, Lyutfi E, Kirneva R, Bratoeva K.In search of the ninth discipline: The history of pathophysiology, with an emphasis on pathophysiology in varna, Bulgaria-celebrating 100 years of pathophysiology in Bulgaria.Cureus. 2018;10(4):e2404. doi:10.7759/cureus.2404American Cancer Society.Lung cancer causes.Lee YC, Lee YC, Li CY, Lee YL, Chen BL.BRCA1andBRCA2gene mutations and lung cancer sisk: a meta-analysis.Medicina (Kaunas). 2020;56(5):212. doi:10.3390/medicina56050212American Cancer Society.Lung cancer risk factors.American Lung Association.Lung cancer causes & risk factors.American Cancer Society.Lung cancer signs & symptoms.
American Cancer Society.Types of lung cancer.
Stoyanov GS, Naskovska G, Lyutfi E, Kirneva R, Bratoeva K.In search of the ninth discipline: The history of pathophysiology, with an emphasis on pathophysiology in varna, Bulgaria-celebrating 100 years of pathophysiology in Bulgaria.Cureus. 2018;10(4):e2404. doi:10.7759/cureus.2404
American Cancer Society.Lung cancer causes.
Lee YC, Lee YC, Li CY, Lee YL, Chen BL.BRCA1andBRCA2gene mutations and lung cancer sisk: a meta-analysis.Medicina (Kaunas). 2020;56(5):212. doi:10.3390/medicina56050212
American Cancer Society.Lung cancer risk factors.
American Lung Association.Lung cancer causes & risk factors.
American Cancer Society.Lung cancer signs & symptoms.
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