What is lung cancer?

Lung cancer is cancer that starts in the cells that make up the lungs. It isn’t cancer that spreads to the lungs from other parts of the body. This is key because treatment is based on the original site of the tumor. For example: If a tumor begins in the breast and spreads to the lungs, it would be treated as metastatic breast cancer—not lung cancer.

Lungs are sponge-like organs in your chest. Their job is to bring oxygen into the body and to get rid of carbon dioxide. When you breathe air in, it goes into your lungs through your windpipe. The trachea divides into tubes called bronchi, which enter the lungs. These split into smaller branches called bronchioles. At the end of the bronchioles are tiny air sacs called alveoli. The alveoli move oxygen from the air into your blood. They take carbon dioxide out of the blood. This leaves your body when you breathe out.

How common is lung cancer?

About 250,000 new cases of lung cancer are diagnosed each year. The average age of those who receive a diagnosis is 70.

Overview

What are the types of lung cancer?

There are two types of lung cancer: non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Understanding the differences between these types may lessen anxiety about your diagnosis and treatment.

Non-small cell lung cancer: NSCLC accounts for 85% to 90% of lung cancer cases. Each subtype is named for the type of cell it develops in. There are three subtypes.

• Adenocarcinoma: This is the most common type of lung cancer—particularly among non-smokers who get the disease. It tends to appear on the outer edges of the lungs and grows more slowly than the other subtypes.
• Squamous cell carcinoma (epidermoid carcinoma): This type of cancer develops more often in smokers or former smokers than lifetime nonsmokers. It tends to start in the center of the lungs near the bronchial tubes.
• Large cell carcinoma: The least common NSCLC, large cell carcinoma can begin anywhere in the lung. It tends to grow more quickly than the other subtypes, which can make it harder to treat.

Small cell lung cancer: Only about one in 10 to three in 20 people diagnosed with lung cancer have small-cell lung cancer. It's also almost exclusively found in smokers. It tends to grow more quickly than NSCLC. It often spreads to other parts of the body at an earlier stage.

Symptoms

What are the signs of lung cancer?

Lung cancer often doesn't cause symptoms in its early stages. This is when it's small and hasn't spread. In fact, many lung cancers don't cause symptoms until they've already spread.

When lung cancer does cause symptoms, they’re often like those you might have anyway if you smoke. For example, some early symptoms of lung cancer include shortness of breath and coughing.

These are some of the more common symptoms of lung cancer:

• Cough that doesn’t go away or gets worse over time
• Chest pain, which might be worse when coughing or breathing in deeply
• Coughing up blood or rust-colored mucus
• Shortness of breath
• Hoarseness
• Wheezing
• Appetite loss
• Unexpected weight loss
• Feeling tired or weak
• Pneumonia or bronchitis occurring more than normal for you

Some symptoms can be caused by lung cancer spreading to other parts of the body:

• Trouble breathing that's getting worse
• Bone pain
• Belly or back pain
• Yellowing of skin and eyes (jaundice)
• Headache, seizures, or confusion
• Weakness or numbness in an arm or leg
• Enlarged lymph nodes in the neck
• Drooping eyelid
• Problems talking

Risk Factors

What causes lung cancer can be varied. But there are risk factors that increase the likelihood of developing lung cancer. Some risk factors can be controlled and some cannot.

• Air pollution
• Asbestos
• Chemicals
• Family history of lung cancer
• Personal history of lung cancer
• Radiation therapy to the chest
• Radon
• Secondhand smoke
• Smoking

Smoking tobacco is the leading risk factor for lung cancer. The longer you smoke, and the more you smoke each day, the higher your risk. Cigarettes are the main cause, but cigar and pipe smoking are almost as likely to cause the disease. Smoking is linked to about eight in 10 lung cancer deaths.

For people who smoke, this information might seem overwhelming. Yet, it’s important to know you’re in control of this risk factor. Quitting smoking, even after many years, can substantially lower your risk for lung cancer.

Can you get lung cancer without smoking?

You can get cancer without smoking. Secondhand smoke is another leading cause of lung cancer. Quitting smoking will lower your risk for lung cancer and lowers the risk of your loved ones developing cancer, as well.

Prevention

How to prevent lung cancer

One of the most important ways to prevent getting lung cancer is to not smoke or to quit smoking.

Other ways to help prevent cancer include:

• Doing moderate to intense physical activity at least three times a week for 30 minutes
• Eating healthy, including lots of fruits and vegetables
• Getting your home tested for radon
• Avoiding chemical exposure at work and home

Are there screening tests for lung cancer?

Studies have shown that low-dose CT (LDCT) scans can help detect lung cancer early in certain high-risk people. This specifically includes heavy smokers ages 50 to 77. Heavy smokers are defined as smoking at least one pack a day for over 20 years.

LDCT scans use X-rays to create detailed 3-D images of your lungs. The scans are painless and require no special preparation. You will lie down on a narrow table as your body passes through a ring-shaped CT scanner. You may be asked to hold your breath a few times during the test.

LDCT scans can spot abnormal areas that regular chest X-rays might miss. The benefit is significant: a lower risk of dying from lung cancer.

Keep in mind, LDCT scans do not find all lung cancers. It’s also possible the cancers they do find may have already progressed to a later stage.

Diagnosis

How is lung cancer diagnosed?

If your health care provider thinks you may have lung cancer, you will need certain exams and tests to be sure. You might need to:

• Have blood drawn. A needle might be used to take a small amount of blood from your hand or arm. Blood tests can show how well certain organs are working and give an idea of your overall health.
• Get a chest X-ray. This is done to look for changes in your lungs, like tumors or fluid buildup.
• Get a chest X-ray. This is done to look for changes in your lungs, like tumors or fluid buildup.

Any of these tests might suggest that you have lung cancer. If imaging tests show something that doesn't look normal, such as a mass or fluid, you'll need to have a biopsy. This is when a health care provider takes out a tiny sample of the mass or some of the fluid for testing at a lab. A biopsy is almost always needed to diagnose lung cancer.

A lung biopsy can be done in many ways:

• Needle biopsy
• Bronchial or transbronchial biopsy
• Endobronchial ultrasound (EBUS)

If the biopsy confirms lung cancer, your providers likely will order more tests. The test results will help determine if the cancer has spread beyond the lungs and what treatment options are best for you.

How is lung cancer staged?

When staging lung cancer, the following three factors are considered:

• The tumor. How big is it? Has it reached other nearby structures?
• The nearby lymph nodes. Has cancer spread to them? If so, which lymph nodes—the lymph nodes near the tumor, or the lymph nodes in the center of the chest (mediastinal lymph nodes)? If the mediastinal lymph nodes contain cancer, are both sides of the chest affected? Or is cancer only in the nodes on the same side as the tumor?
• Metastasis. Has the cancer spread from the lungs to other parts of the body?

Both non-small cell and small cell lung cancers are then put into stage groupings based on this information. These groupings give an overall description of the cancer. A stage grouping can have a value of 0 to 4. The higher the number, the more advanced the cancer is.

Lung cancer staging is complex. Be sure to ask your healthcare provider to explain the stage of your cancer to you in a way you can understand.

Treatment

How is lung cancer treated?

Several types of treatment can be used for lung cancer. Different combinations of treatment may be used, depending on the type and stage (extent) of the cancer, and other factors. Each treatment has its own goals. Here is an overview of each type of treatment:

• Surgery. If you have non-small cell lung cancer (NSCLC) that has not spread, surgery is often the first choice for treatment. Surgery is used for only a small number of people with very early-stage small cell lung cancer (SCLC). Surgery for lung cancer is often followed by other treatments.
• Radiation therapy.Radiation therapy uses high energy X-rays or radioactive particles to destroy cancer cells. It is often a choice when you have an early-stage tumor but are not healthy enough for surgery. It can also be used for more advanced cancers. It may be used by itself or with chemotherapy. Radiation therapy can also be used to help relieve symptoms from cancer that has spread.
• Chemotherapy. Chemotherapy is the use of anticancer medicines. It is usually part of the treatment for SCLC and NSCLC.
• Targeted therapy. Several targeted medicines can be used to treat some advanced NSCLCs, either alone or along with chemotherapy.
• Immunotherapy.Medicines called immune checkpoint inhibitors can be used to treat advanced NSCLC.
• Supportive care. Your health care provider may advise therapies that help ease your symptoms, but don’t treat the cancer. These can sometimes be used along with other treatments.

What is the lung cancer survival rate?

According to the American Cancer Society, the five-year survival rate is based on whether the cancer has spread.

The five-year survival rate for non-small cell lung cancer is about 65% if it has remained in the area of origin, known as localized. The five-year survival rate is 37% when the cancer has spread to areas nearby, like the lymph nodes. The five-year survival rate is 9% when the cancer has spread to distant areas in the body.

The five-year survival rate for small cell lung cancer is 30% when it’s localized, 18% when it has spread to other areas surrounding the lungs and 3% when it has spread to distant areas in the body.