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Home > Health Library > Lung Cancer
Lung cancer starts when abnormal cells grow out of control in the lung. They can invade nearby tissues and form tumors. Lung cancer can start anywhere in the lungs and affect any part of the respiratory system.
The cancer cells can spread, or metastasize, to the lymph nodes and other parts of the body.
Lung cancers are divided into small cell lung cancers (SCLC) and non-small cell lung cancers (NSCLC). Small cell lung cancers usually grow more quickly and are more likely to spread than non-small cell lung cancer.
Lung cancer is the leading cause of cancer deaths in the world.footnote 1
Most lung cancer is caused by smoking. But sometimes lung cancer develops in people who have never smoked.
Being exposed to secondhand smoke, arsenic, asbestos, radioactive dust, or radon can increase your chances of getting lung cancer. People who are exposed to radiation at work or elsewhere have a higher chance of getting lung cancer.
The first signs of lung cancer may include:
Because these symptoms are so general, many people don't suspect lung cancer. And by the time they see a doctor, often the cancer has already started to spread.
If the cancer spreads within and beyond the chest, other symptoms may occur.
Your symptoms and your medical history—especially if you have any history of cancer in your family—will help your doctor decide how likely it is that you have lung cancer and whether you need tests to be sure.
Lung cancer is usually first found on a chest X-ray or a CT scan. More tests are done to find out what kind of cancer cells you have and whether they have spread beyond your lung. These tests help your doctor and you find out what stage the cancer is in. The stage is a rating to measure how big the cancer is and how far it has spread.
Treatment for lung cancer may include surgery, chemotherapy, radiation, or a combination of these therapies. Targeted therapy and immunotherapy may also be used.
Finding out that you have cancer can change your life. You may feel like your world has turned upside down and you have lost all control. Talking with family, friends, or a counselor can really help. Ask your doctor about support groups. Or call the American Cancer Society (1-800-227-2345) or visit its website at www.cancer.org.
Lung cancer that is caused by smoking can be prevented. So it is important to stop smoking—or to stop being around someone else's smoke.
Even if you have smoked a long time, quitting can lower your chances of getting cancer. If you already have lung cancer, quitting makes your treatment work better and can help you live longer.
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More than 8 out of 10 lung cancers are caused by smoking.footnote 3 Tobacco smoke contains carcinogens—substances that cause cancer. These substances damage lung cells, and over time the damaged cells can turn into lung cancer.
The more you smoke and the longer you have smoked, the higher your chances of getting lung cancer. You lower your chances when you quit or cut down on how much you smoke.
A few people get lung cancer after being exposed to other harmful substances, including asbestos, radioactive dust, radon, or radiation such as X-rays.
Cancer also may be caused by gene changes (mutations) that occur as you get older.
Symptoms of lung cancer may include:
When lung cancer spreads, there may be other symptoms. For example, if it spreads to the spine or bones, it may cause pain in the back or other bones or cause weakness in the arms or legs. If it spreads to the brain, it may cause seizures, headaches, or vision changes.
Lung cancer can start anywhere in the lungs and may affect any part of the respiratory system. This can cause breathing or heart problems, such as:
As lung cancer grows, it may spread (metastasize) to other parts of the body. Lung cancer is classified in stages, which describe how far the cancer has grown and spread.
The long-term outcome (prognosis) for lung cancer depends on how much the cancer has grown and spread.
A risk factor for lung cancer is something that increases your chance of getting this cancer. Having one or more of these risk factors can make it more likely that you will get lung cancer. But it doesn't mean that you will definitely get it. And many people who get lung cancer don't have any of these risk factors.
About 85 out of 100 lung cancers are related to cigarette smoking.footnote 4 Smoking cigars or a pipe may also increase your risk for lung cancer.
Your risk of getting lung cancer increases:
Quitting smoking lowers your risk for getting cancer, and your risk keeps going down as long as you don't smoke. Even cutting down how much you smoke may reduce your risk (but not as much as quitting completely).
If you live with a smoker, you have a higher risk for lung cancer compared with a person who lives in a nonsmoking environment.
For more information, see the topic Quitting Smoking.
Exposure to some substances may increase your risk for lung cancer, including:
Some gene changes (mutations) can increase the risk of getting lung cancer. These gene changes mostly occur as a person gets older.
Be sure to follow your doctor's instructions about calling when you have problems, new symptoms, or symptoms that get worse.
Call 911 or other emergency services immediately if you:
Call your doctor now if you have:
Call your doctor to find out if you should be seen if you:
If you have been diagnosed with cancer, be sure to follow your doctor's instructions about calling when you have problems, new symptoms, or symptoms that get worse.
Your doctor will first do a physical exam and ask about your medical history to find out your risk for lung cancer and look for any lung problems. The exam may include a chest X-ray and blood test.
If your exam suggests that you may have lung cancer, your doctor may recommend other tests, such as:
After lung cancer has been diagnosed, testing is done to find out whether the cancer has spread (metastasized) to other organs in your body and to determine the stage of the cancer.
If you have non-small cell lung cancer, your doctor may check for tumor markers (biomarkers) that are caused by gene changes (mutations) in cancer cells. This can help your doctor choose the treatment that will work best for you.
A person whose lungs aren't working well may not be a good candidate for surgery. If surgery to remove cancer in all or part of a lung is being considered, the following tests may be done:
Screening tests help your doctor look for a certain disease or condition before you have any symptoms. This can increase your chances of finding the problem early, when it's more treatable.
Studies haven't yet shown that routine screening for lung cancer saves lives or prevents lung cancer. But it may help people who have the highest risk for lung cancer—people 55 and older who are or were heavy smokers. Talk to your doctor about the pros and cons of lung cancer screening.
Treatment for both non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) may include the following:
Other treatments for NSCLC include:
Your doctor may check for tumor markers (biomarkers), such as EGFR, ALK, and KRAS, that are caused by gene changes (mutations) in cancer cells. This can help your doctor choose the treatment that will work best for you.
Other treatments for SCLC include:
The kind of treatment and the long-term outcome of lung cancer depends on the type and stage of the cancer and also on your age and your overall health.
Some treatments can cause side effects. Home treatment measures may help.
Your quality of life is critical when you are considering your treatment choices. Discuss your personal preferences with your oncologist when he or she recommends treatment.
Additional information about lung cancer is provided by the National Cancer Institute at www.cancer.gov/cancertopics/types/lung.
If you have been recently diagnosed with lung cancer, you may feel denial, anger, and grief. Reactions vary from person to person. Talk to your doctor about steps you can take to help with your emotional reactions.
If you are having a hard time moving forward with your life, talk with your doctor. Your cancer treatment center may offer counseling services. You may also contact your local chapter of the American Cancer Society to help you find a support group.
Having cancer can change your life in many ways. For support in managing these changes, see the topic Getting Support When You Have Cancer.
After initial treatment for lung cancer, it is important to receive follow-up care.
You may be interested in participating in research studies called clinical trials. Clinical trials are based on the most up-to-date information and are designed to find better ways to treat people who have cancer.
People who do not want standard treatments or are not cured by standard treatments may want to participate in clinical trials. These are ongoing in most parts of the United States and in some other countries around the world for all stages of lung cancer.
Palliative care is a kind of care for people who have a serious illness. It's different from care to cure your illness. Its goal is to improve your quality of life—not just in your body but also in your mind and spirit. You can have this care along with treatment to cure your illness.
Palliative care providers will work to help control pain or side effects. They may help you decide what treatment you want or don't want. And they can help your loved ones understand how to support you.
One study of people with non-small cell lung cancer who started palliative care when they were diagnosed with lung cancer found that they not only felt better but also lived a little longer than the people who didn't have palliative care.footnote 6
If you're interested in palliative care, talk to your doctor.
For more information, see the topic Palliative Care.
For some people who have advanced cancer, a time comes when treatment to cure the cancer no longer seems like a good choice. This can be because the side effects, time, and costs of treatment are greater than the promise of cure or relief. But you can still get treatment to make you as comfortable as possible during the time you have left. You and your doctor can decide when you may be ready for hospice care.
For more information, see the topics:
Most lung cancers are caused by smoking. If you use tobacco, you can help prevent lung cancer by quitting. For more information, see the topic Quitting Smoking.
You may be able to make other changes in your life that can help prevent lung cancer:
During treatment for any stage of lung cancer, there are steps you can take at home to manage some symptoms and side effects. Be sure to follow any instructions your doctor has given you.
Other issues you may be able to handle at home include:
If you smoke and have lung cancer, quitting smoking will make your treatment more effective and may help you live longer. Smoking delays healing after surgery, so you may have a better recovery from lung cancer surgery if you have quit smoking.
People with early-stage lung cancer who continue to smoke during radiation therapy have been shown to have shorter survival times than those who do not smoke.footnote 7
Smoking may also make chemotherapy less effective. The nicotine in tobacco seems to help the cancer cells and their blood supply multiply while also protecting the cancer cells from destruction.footnote 8
For information and help quitting smoking, see the topic Quitting Smoking.
Medicines for lung cancer mainly involve chemotherapy. Other medicines may be used to help with pain.
Chemotherapy is the most effective treatment for small cell lung cancer. It can help control the growth and spread of the cancer, but it cures lung cancer in only a small number of people. It also may be used to treat more advanced stages of non-small cell lung cancer.
Chemotherapy is called a systemic treatment because the medicines enter your bloodstream, travel through your body, and kill cancer cells both inside and outside the lung area. Some chemotherapy drugs are taken by mouth (orally), while others are injected into a vein (intravenous, or IV).
Chemotherapy medicines used for lung cancer may include carboplatin, cisplatin, or paclitaxel.
Most chemotherapy causes some side effects. Your doctor may prescribe medicines to control nausea or vomiting.
You may be concerned about losing your hair from cancer treatment. Not all chemotherapy medicines cause hair loss, and some people have only mild thinning that is noticeable only to them. Talk to your doctor about whether hair loss is an expected side effect of the medicines you will receive.
Chemotherapy may be combined with surgery. It may be given before or after surgery to kill cancer cells.
Pain is one of the main concerns of people who have cancer. But cancer pain can almost always be controlled with medicines and other options. Medicines used for cancer pain include prescribed medicines, such as hydrocodone or morphine, or nonprescription medicines, such as aspirin and similar drugs.
Lung surgery to remove the cancer may be an option when your cancer is in only one lung or present in one lung and in nearby lymph nodes. It usually is done only if your doctor thinks all the cancer can be removed and your general health is good enough for you to handle the surgery.
Nearby lymph nodes may also be removed to find out whether the cancer has spread.
The type of surgery performed depends on the location and size of your lung cancer:
The side effects from surgery will depend on the type of surgery that you have. There is less pain with surgery that is minimally invasive (VATS) than the traditional surgery (thoracotomy). You may have numbness and tingling in the chest area. This usually goes away in a few weeks or months.
Radiation treatment is the use of high-energy X-rays to kill cancer cells and shrink tumors. Most radiation for lung cancer is given externally, which means that the radiation comes from a machine outside the body.
Radiation is often used in combination with surgery or chemotherapy or both. But it may be used alone if surgery is not possible.
People who can't have surgery may have a special type of radiation called stereotactic radiosurgery (SRS). This isn't surgery but a series of very high doses of radiation that are aimed at the cancer. SRS is usually given to treat tumors that have spread to the brain. SRS may also be called gamma knife radiosurgery, cyberknife, stereotactic ablative radiotherapy (SABR), or stereotactic body radiotherapy (SBRT).
Radiation may be used to prevent small cell lung cancer from growing in your brain. This is called prophylactic cranial irradiation (PCI).
Radiation also may be used as palliative care to:
Radiation may cause side effects, such as skin changes, fatigue, and trouble swallowing.
People sometimes use complementary treatments along with medical treatment to help relieve symptoms and side effects of cancer treatments. Some of the complementary therapies that may be helpful include:
These mind-body treatments may help you feel better. They can make it easier to cope with treatment. They also may reduce chronic low back pain, joint pain, headaches, and pain from treatments.
Before you try a complementary therapy, talk to your doctor about the possible value and potential side effects. Let your doctor know if you are already using any such therapies. They are not meant to take the place of standard medical treatment.
Silverstri GA, Jett JR (2010). Clinical aspects of lung cancer. In R Mason et al., eds., Murray and Nadel's Textbook of Respiratory Medicine, 5th ed., vol. 2, pp. 1116–1144. Philadelphia: Saunders.
American Cancer Society (2012). Cancer Facts and Figures 2012. Atlanta: American Cancer Society. Available online: http://www.cancer.org/Research/CancerFactsFigures/CancerFactsFigures/cancer-facts-figures-2012.
Khuri FR (2016). Lung cancer and other pulmonary neoplasms. In L Goldman, A Shafer, eds., Goldman-Cecil Medicine, 25th ed., vol. 2, pp. 1303–1313. Philadelphia: Saunders.
U.S. Department of Health and Human Services (2010). A Report of the Surgeon General: How Tobacco Smoke Causes Disease—The Biology and Behavioral Basis for Smoking-Attributable Disease Fact Sheet. Available online: http://www.surgeongeneral.gov/library/tobaccosmoke/factsheet.html.
Aldington S, et al. (2008). Cannabis use and risk of lung cancer: A case-control study. European Respiratory Journal, 31(2): 280–286.
Temel JS, et al. (2010). Early palliative care for patients with metastatic non–small-cell lung cancer. New England Journal of Medicine, 363(8): 733–742.
Fox JL, et al. (2004). The effect of smoking status on survival following radiation therapy for non–small cell lung cancer. Lung Cancer, 44(3): 287–293.
Dasgupta P, et al. (2006). Nicotine inhibits apoptosis induced by chemotherapeutic drugs by up-regulating XIAP and survivin. Proceedings of the National Academy of Sciences, 103(16): 6332–6337.
Other Works Consulted
National Cancer Institute (2011). Small Cell Lung Cancer PDQ: Treatment—Patient Version. Available online: http://www.cancer.gov/cancertopics/pdq/treatment/small-cell-lung/Patient.
National Cancer Institute (2012). Non-Small Cell Lung Cancer PDQ: Treatment—Patient Version. Available online: http://www.cancer.gov/cancertopics/pdq/treatment/non-small-cell-lung/Patient.
National Cancer Institute (2012). Small Cell Lung Cancer PDQ: Treatment—Health Professional Version. Available online: http://www.cancer.gov/cancertopics/pdq/treatment/small-cell-lung/healthprofessional.
Neville A (2009). Lung cancer, search date May 2008. Online version of BMJ Clinical Evidence: http://www.clinicalevidence.com.
Current as of:
September 8, 2021
Author: Healthwise StaffMedical Review: E. Gregory Thompson MD - Internal MedicineKathleen Romito MD - Family MedicineMichael Seth Rabin MD - Medical Oncology
Current as of: September 8, 2021
Author: Healthwise Staff
Medical Review:E. Gregory Thompson MD - Internal Medicine & Kathleen Romito MD - Family Medicine & Michael Seth Rabin MD - Medical Oncology
To learn more about Healthwise, visit Healthwise.org.
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