Lung cancer is a disease that starts from abnormal cells inside the lungs growing out of control. Cancer cells can spread from the lungs to lymph nodes or to other organs, like the bone, brain, or liver. As the cancer cells multiply, they form tumors that damage the lungs and the organs where they spread, and can eventually stop those organs from working effectively.
Lung cancer is one of the most common cancers in the United States, and the leading cause of cancer-related deaths. Yet the outlook for lung cancer is improving as the survival rate rises. Many lung cancers are curable if they're caught early and can be removed surgically. Even when the cancer isn't curable, treatments like chemotherapy, targeted therapy, and immunotherapy can slow its growth and improve quality of life.
Lung cancer is divided into two main types: Non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). The types are based on what kind of cell the cancer started in and how the cancer cells look under a microscope. Knowing the type helps oncologists choose the treatment that's most likely to work best against it.
Non-Small Cell Lung Cancer (NSCLC)
NSCLC is the most common type of lung cancer, making up about 80 percent of lung cancers. NSCLC grows and spreads to other parts of the body more slowly than SCLC.
NSCLC is further divided into three main subtypes, and each one grows from a different kind of lung cell:
Adenocarcinoma is the most common form of NSCLC. It starts in glandular cells, which line the surface of the lungs and produce mucus.
Squamous cell carcinoma grows from squamous cells — flat, scale-like cells that line the airway. This subtype is common in former or current smokers.
Large cell neuroendocrine carcinoma can start in any part of the lung. Because it grows more quickly than adenocarcinoma and squamous cell carcinoma, this subtype may be more challenging to treat.
Small Cell Lung Cancer (SCLC)
SCLC makes up only 10 to 15 percent of all lung cancers, but it grows faster than NSCLC. By the time this cancer is diagnosed, it has often spread beyond the lungs, but it initially responds well to treatment with radiation and chemotherapy.
Rare Lung Cancers
These are less common types of lung cancer:
Lung carcinoid tumors, sometimes called low-grade neuroendocrine carcinoma, are made up of neuroendocrine cells, which act like both nerve cells and hormone-releasing cells. These cancers are rare and they often grow slowly.
Pancoast tumors grow from the upper part of the lung. They're usually NSCLC and they may respond well to surgery, chemotherapy, or radiation.
Cancers that start in other places, like the breast, kidney, or pancreas, can spread to the lungs. These cancers keep the name of the organ where they started. For example, a cancer that spreads from the breast to the lungs is called metastatic breast cancer, not lung cancer.
The signs and symptoms of lung cancer depend on the stage of the cancer, and may be different for each person. Early stage, and sometimes even later stage, lung cancer often causes no symptoms. The most common ones are:
A cough that doesn't go away or that gradually gets worse
Appetite loss
Chest pain that gets worse when breathing, coughing, or laughing
Having these symptoms doesn't necessarily mean you have lung cancer. Many other conditions cause the same signs and symptoms. Only a doctor can confirm the diagnosis.
When lung cancer spreads, there may be additional signs and symptoms, based on where the cancer is located:
Bones: Pain in bones like the hip and back
Brain: Headache, dizziness, balance problems, unsteady walk, numbness or weakness in an arm or leg, seizures
Liver: Yellowish color to the skin and whites of the eyes (jaundice)
Lymph nodes: Swollen glands in the neck or shoulder
The leading cause of lung cancer is tobacco smoking, which is responsible for up to 90 percent of cases. The longer someone smokes and the more they smoke, the greater their risk becomes. People who are exposed to secondhand smoke are also at increased risk for lung cancer.
However, it's possible to develop lung cancer without ever smoking. As smoking rates have declined, the proportion of lung cancers in never-smokers has risen.
These factors also increase lung cancer risk:
Rado This gas is the second-leading cause of lung cancer, and the main identifiable cause among nonsmokers.Radon seeps into homes through the soil, and it could be in 1 out of every 15 homes in the United States. Because this gas is odorless, homeowners may not realize they're exposed unless they test for it. If your home has high levels of radon, mitigation systems can be installed to lower the levels.
Other Toxic Substances Exposure to asbestos, uranium, beryllium, silica, cadmium, vinyl chloride, arsenic, and nickel compounds are linked to an increased risk for lung cancer. People who breathe in asbestos while working in places like mines, textile plants, and shipyards are at high risk for both lung cancer and mesothelioma — a type of cancer that starts in the lining of the lung.
Pollution Air pollution — for example, from diesel exhaust — is believed to cause up to 2 percent of lung cancer deaths in the United States. Indoor air pollution from wood and coal stoves and heating units also poses a risk.
Radiation Therapy Getting radiation to the chest, such as during treatment for breast cancer, increases the risk for future lung cancer, especially in smokers.
Family History of Lung Cancer The risk is higher if a close relative like a sibling or parent had lung cancer. This can be due to shared genes or to common exposures like tobacco smoke, and it’s unclear whether genetics or environment has a stronger influence on lung cancer development.
The process of diagnosing lung cancer starts with your medical history, a discussion of symptoms, and a physical exam. If the doctor suspects lung cancer, they'll order one or more of the following tests to confirm the diagnosis.
Imaging Tests
These tests take pictures from inside the body. They can help find cancer, show how far it has spread, and see if treatment is slowing or stopping the cancer:
Chest X-ray uses a small amount of radiation to show any abnormal areas in the lung.
Computerized tomography (CT) takes many X-ray pictures from different angles and combines them into cross-sectional images with a computer. A CT scan can show tumors in greater detail than an X-ray.
Magnetic resonance imaging (MRI) uses strong magnets and radio waves to make pictures. An MRI can show whether the cancer has spread to places like the brain or liver.
Positron emission tomography (PET) uses radioactive sugar to find the cancer. Cancer cells take up more sugar than healthy cells because they're more metabolically active. Using a special camera, the radioactive material “lights up” in areas where there is cancer. A PET scan can show whether the cancer has spread, and where it is located.
Biopsies
Imaging tests can only show signs of cancer. The only way to confirm the diagnosis is by taking a sample of cells from in or around the lungs, usually by a biopsy, and testing it in a lab.
A biopsy can be done in a few ways:
Fine needle tissue aspiration uses a thin, hollow needle to remove a few cells or a small amount of tissue.
Core biopsy removes a larger amount of tissue with a bigger, hollow needle.
Open biopsy removes a tissue sample through an incision in the chest between the ribs.
Other Tests
Additional methods for collecting samples to test for lung cancer include:
Thoracentesis This test uses a hollow needle, inserted between the ribs, to drain fluid from around the lungs. A lab checks the fluid for the presence of cancer cells.
Bronchoscopy During this test, a flexible tube called a bronchoscope passes through the mouth or nose into the lungs to locate tumors and possibly biopsy them.
Endobronchial Ultrasound (EBUS) Bronchoscopy The bronchoscope has an ultrasound at the tip, which lets the doctor see lymph nodes and other structures between the lungs and take biopsy samples.
Mediastinoscopy and Mediastinotomy These tests allow the doctor to obtain tissue samples from the area between the lungs, called the mediastinum. Mediastinoscopy inserts a lighted tube through a small incision in the chest. Mediastinotomy is done through a larger incision.
Thoracoscopy or Video-Assisted Thoracoscopy (VATS) By making an incision between the ribs and inserting an instrument called a thoracoscope, the doctor can look for abnormal areas and remove tissue for testing.
Molecular or Biomarker Testing The tumor sample can also be tested for certain genetic changes or proteins. These tests can show whether someone is a good candidate for targeted therapy.
Common treatments for lung cancer include surgery, radiation therapy, chemotherapy, targeted therapy, and immunotherapy. The choice of treatment depends on the type of lung cancer, its stage (how far it has spread), and the results of molecular testing.
Surgery
Surgery to remove part or all of the affected lung(s), called lung resection, is a treatment for early-stage NSCLC. In some cases it can cure the disease. It's used less often for SCLC because the cancer has usually spread by the time it is diagnosed.
Other surgical procedures are part of palliative care, done to relieve symptoms. Thoracentesis and pleurodesis remove fluid from the chest to make breathing easier. A tube called a stent may be placed to widen an airway that the tumor is blocking.
Chemotherapy
These medicines travel throughout the bloodstream, killing cancer cells all over the body. Chemotherapy is usually part of the treatment for SCLC. For NSCLC, it may be used before surgery to shrink the tumor and make it easier to remove, after surgery to kill any cancer cells that were left behind, or to treat cancer that has spread outside the lung.
Some of the chemotherapy drugs that treat lung cancer are:
cisplatin
carboplatin
etoposide (VP-16)
paclitaxel (Taxol)
docetaxel (Taxotere)
gemcitabine (Gemzar)
pemetrexed (Alimta)
Some people get a combination of chemotherapy drugs, or chemo plus radiation therapy.
Immunotherapy
This type of medicine helps the immune system attack the cancer. Immune checkpoint inhibitors are a type of immunotherapy that treats both NSCLC and SCLC. Checkpoints are proteins like PD-1, PD-L1, and CTLA-4 that sit on the surface of immune cells. They turn “off” the immune system to avoid attacking the body's own healthy cells. Cancer cells use checkpoints to prevent the immune system from attacking them. Checkpoint inhibitors block checkpoint proteins to turn the immune cells back “on.”
Bispecific T-cell engager (BiTE) is a type of immunotherapy prescribed for SCLC. This medicine contains two “arms.” One attaches to immune cells called T cells. The other attaches to a protein on the surface of SCLC cells. The BiTE brings the immune cells to the cancer cells to more effectively attack the cancer. Tarlatamab (Imdelltra) is an example of a BiTE immunotherapy that is given intravenously.
Targeted Therapy
These medications work by blocking proteins or other substances that help the cancer cells grow and divide. Targeted therapy is usually reserved for NSCLC that has spread. Many of these medications are for people with specific gene mutations, such as epidermal growth factor (EGFR). Sometimes targeted therapy is combined with chemotherapy to improve the effectiveness.
Examples of targeted therapy drugs are:
KRAS inhibitors: adagrasib (Krazati) and sotorasib (Lumakras)
This treatment uses high-energy rays to kill cancer cells. Radiation is either delivered from a machine outside the body, or from a radioactive material placed inside the body near the cancer.
There are several types of radiation therapy, such as stereotactic radiation, which uses higher doses of focused beams in fewer treatments, or proton therapy, which uses positively charged proton cells that are focused on the tumor.
Radiation therapy is an option for both NSCLC and SCLC. In NSCLC, it's given before surgery to make the tumor smaller, after surgery to kill any remaining cancer cells, or on its own in people who can't have surgery.
In late-stage lung cancer, radiation therapy helps to relieve pain and other symptoms caused by the cancer spread. Chemotherapy is sometimes used in tandem with radiation therapy.
Radiofrequency Ablation (RFA)
RFA uses high-energy radio waves to create heat that destroys cancer cells. The heat is applied by a needle-like probe placed through the skin, or via bronchoscopy. RFA may be used if you’re unable to have surgery, to provide pain relief, or in combination with other treatments.
Angiogenesis Inhibitors
Angiogenesis is the growth of new blood vessels from existing blood vessels. Angiogenesis inhibitors stop this growth, limiting the flow of blood and oxygen to the tumor. This can slow the growth and spread of the cancer. Angiogenesis inhibitors used for NSCLC include bevacizumab (Avastin) and ramucirumab (Cyramza). They won’t get rid of the tumors, so angiogenesis inhibitors are commonly used alongside other treatments.
Complementary and Integrative Therapies
Complementary therapies work alongside cancer treatments to relieve side effects like pain and anxiety, and improve quality of life. When used together, complementary and traditional treatments like chemotherapy and radiation are known as integrative therapies.
Examples of complementary therapies for lung cancer are:
Meditation or deep breathing to relieve stress and anxiety
Dietary changes and supplements to improve overall health and promote recovery from treatment
Speak with your doctor before starting any complementary therapies, including dietary changes and supplements, as they may interfere with your treatments or your medical conditions.
Because cigarette smoking causes up to 90 percent of lung cancer cases in the United States, the most important way to prevent lung cancer is to quit smoking or never start. Smoking cessation methods like medication and nicotine replacement products can help reduce the urge to smoke. Also avoid secondhand smoke.
These are a few other ways to lower lung cancer risk:
Have your home tested for radon, and treated if necessary.
Avoid substances that have been linked to lung cancer, such as asbestos, at work or in the home. Using proper personal protective equipment helps minimize the risk when working with these substances.
Eat a diet that's high in colorful fruits and vegetables.
To detect lung cancer early, the United States Preventive Services Task Force (USPSTF) recommends annual low-dose computed tomography (CT) screening for people ages 50 to 80 who currently smoke or quit within the past 15 years, and have a 20 pack-year smoking history. That's the equivalent of smoking one pack of cigarettes per day for 20 years, or two packs a day for 10 years.
These healthy lifestyle tips might both lower the risk for lung cancer, and improve the outcome in people who have already been diagnosed.
Avoid Tobacco Smoke
Most lung cancers, and up to 90 percent of deaths from lung cancer, are linked to tobacco products. People who smoke cigarettes are 15 to 30 times more likely to die from lung cancer than nonsmokers.
Eat a Balanced Diet
Eating a balanced diet, with plenty of fruits and vegetables, is linked to reduced cancer risk, as well as improving your overall health. Limiting red meat and added sugars is also beneficial.
Stay Active
People who lead an active lifestyle with plenty of exercise are at lower risk for cancer in general, including lung cancer. In people who already have lung cancer, exercise helps to relieve fatigue, as well as improve lung function and quality of life. People who are more fit also have better odds of surviving.
The recommended amount of aerobic exercise is 150 minutes per week.
The prognosis for someone diagnosed with lung cancer depends on the type and the stage at which they were diagnosed. In general, early-stage lung cancers have a better outlook, and are sometimes curable with surgery.
On average, 28 percent of people diagnosed with NSCLC are still alive five years after their diagnosis. The five-year relative survival rates for NSCLC are:
65 percent when the cancer hasn't spread outside the lung
37 percent when the cancer has spread to nearby tissues
9 percent when the cancer has spread to distant organs or tissues
For SCLC, the five-year relative survival rates are:
30 percent when the cancer hasn't spread outside the lung
18 percent when the cancer has spread to nearby tissues
3 percent when the cancer has spread to distant organs or tissues
Survival rates for lung cancer are low compared with other cancers because this cancer often isn't diagnosed until after it has spread. However, the outlook for lung cancer has improved by 26 percent in recent years.
Some complications of lung cancer happen as the cancer grows and presses on organs. Shortness of breath occurs when the tumor blocks the airways or fluid builds up in the lungs. Pain may be a sign that cancer has spread to the bones or other organs.
Additional complications can occur as a result of chemotherapy and other treatments:
Just over 226,000 people are diagnosed with lung cancer each year. Most are diagnosed at age 65 or older.
This is the deadliest of all cancers in terms of numbers. Although lung cancer makes up just 11 percent of new cancer cases, it's responsible for 1 in 5 of all cancer-related deaths.
Rates of lung cancer differ by race. Black men are 12 percent more likely to develop this cancer than white men. But that's not the case with Black women, who have a 16 percent lower risk of lung cancer than white women.
Although lung cancer survival rates have risen overall, they haven't improved equally for each racial and ethnic group. People of color are less likely to be diagnosed early, and to receive the appropriate treatment, than white people. These disparities have led to worse outcomes for people of color.
Black Americans and Lung Cancer
Black Americans are 15 percent less likely to be diagnosed with lung cancer early compared with white Americans. Once diagnosed, they don't receive treatments, including surgery, at the same rate. And they are 16 percent less likely to survive for 5 years compared with white people with lung cancer.
Black men have the highest rate of lung cancer of all ethnic groups. They are also most likely to die from their cancer, possibly because they are often diagnosed at a younger age, and their cancer isn't detected until it has already spread.
Hispanic Americans and Lung Cancer
Hispanic Americans also face problems getting a timely diagnosis. They are 17 percent less likely to be diagnosed early than white Americans, and 30 percent less likely to receive treatment. As a result, their likelihood of surviving lung cancer is also lower.
New lung cancer treatments that might improve outcomes for Hispanic Americans aren't appropriately tested in this population, who make up just 1 percent of all clinical trial participants. Without enough representation in clinical trials, it's hard to know how new medications might work for Hispanic Americans.
Indigenous Americans and Lung Cancer
Lung cancer is the most common cancer diagnosed in non-Hispanic American Indian/Alaskan Native people living in 5 out of 6 Indian Health Services regions in the United States. This population has the highest smoking rate of any ethnic group in the country.
When it comes to diagnosing and treating lung cancer, American Indians/Alaskan Natives are at a disadvantage compared with white Americans. They are 12 percent less likely to be diagnosed early, 20 percent more likely to not receive any treatment, and 15 percent less likely to survive for at least 5 years after their diagnosis.
There are a few conditions that can increase the risk for lung cancer or overlap with it.
Chronic Obstructive Pulmonary Disease (COPD) This is a chronic lung disease that includes emphysema and chronic bronchitis. Like lung cancer, COPD usually develops because of lung damage from tobacco smoke. People who have COPD are more likely to develop lung cancer.
Idiopathic Pulmonary Fibrosis (IPF) This chronic condition occurs when the lungs become scarred, thick, and stiff. Having IPF increases the risk for lung cancer by as much as 13 percent, and the cancer tends to be more aggressive than usual.
Cardiovascular Disease (CVD) Lung cancer and CVD are both related to smoking. Smoking contributes to CVD by damaging blood vessels. Each of these conditions can complicate the other. CVD is one of the leading causes of death in people with lung cancer, and lung cancer treatments like immune checkpoint inhibitors can damage the heart.
The leading organization devoted to lung health offers a variety of support services. On its website, people with lung cancer can find support groups, a free lung cancer community, and mentors. The association also offers a free Lung HelpLine that will connect you to a healthcare professional.
This nonprofit organization offers information and resources to help lung cancer patients navigate their diagnosis. The foundation also offers the largest online network of support programs, including peer-to-peer support and message boards.
This national organization offers free treatment information, support services, and other resources for those affected by lung cancer. CancerCare also provides counseling from oncology social workers, as well as financial assistance and support groups.
There are two main types of lung cancer — non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Around 80 percent of all lung cancers are NSCLC.
Smoking remains the leading cause of lung cancer, although an increasing number of people who are diagnosed have never smoked.
Treatments for lung cancer include surgery, chemotherapy, radiation therapy, immunotherapy, and targeted therapy.
Despite improvements in survival, lung cancer often isn't diagnosed until it has already spread.
