Lung cancer

Overview

Lung cancer is a kind of cancer that starts as a growth of cells in the lungs. The lungs are two spongy organs in the chest that control breathing.

Lung cancer is the leading cause of cancer deaths worldwide.

People who smoke have the greatest risk of lung cancer. The risk of lung cancer increases with the length of time and number of cigarettes smoked. Quitting smoking, even after smoking for many years, significantly lowers the chances of developing lung cancer. Lung cancer also can happen in people who have never smoked.

Symptoms

Lung cancer typically doesn't cause symptoms early on. Symptoms of lung cancer usually happen when the disease is advanced.

Signs and symptoms of lung cancer that happen in and around the lungs may include:

A new cough that doesn't go away.
Chest pain.
Coughing up blood, even a small amount.
Hoarseness.
Shortness of breath.
Wheezing.

Signs and symptoms that happen when lung cancer spreads to other parts of the body may include:

Bone pain.
Headache.
Losing weight without trying.
Loss of appetite.
Swelling in the face or neck.

When to see a doctor

Make an appointment with your doctor or other healthcare professional if you have any symptoms that worry you.

If you smoke and haven't been able to quit, make an appointment. Your healthcare professional can recommend strategies for quitting smoking. These may include counseling, medicines and nicotine replacement products.

Causes

Lung cancer happens when cells in the lungs develop changes in their DNA. A cell's DNA holds the instructions that tell a cell what to do. In healthy cells, the DNA gives instructions to grow and multiply at a set rate. The instructions tell the cells to die at a set time. In cancer cells, the DNA changes give different instructions. The changes tell the cancer cells to make many more cells quickly. Cancer cells can keep living when healthy cells would die. This causes too many cells.

The cancer cells might form a mass called a tumor. The tumor can grow to invade and destroy healthy body tissue. In time, cancer cells can break away and spread to other parts of the body. When cancer spreads, it's called metastatic cancer.

Smoking causes most lung cancers. It can cause lung cancer in both people who smoke and in people exposed to secondhand smoke. But lung cancer also happens in people who never smoked or been exposed to secondhand smoke. In these people, there may be no clear cause of lung cancer.

How smoking causes lung cancer

Researchers believe smoking causes lung cancer by damaging the cells that line the lungs. Cigarette smoke is full of cancer-causing substances, called carcinogens. When you inhale cigarette smoke, the carcinogens cause changes in the lung tissue almost immediately.

At first your body may be able to repair this damage. But with each repeated exposure, healthy cells that line your lungs become more damaged. Over time, the damage causes cells to change and eventually cancer may develop.

Types of lung cancer

Lung cancer is divided into two major types based on the appearance of the cells under a microscope. Your healthcare professional makes treatment decisions based on which major type of lung cancer you have.

The two general types of lung cancer include:

Small cell lung cancer. Small cell lung cancer usually only happens in people who have smoked heavily for years. Small cell lung cancer is less common than non-small cell lung cancer.
Non-small cell lung cancer. Non-small cell lung cancer is a category that includes several types of lung cancers. Non-small cell lung cancers include squamous cell carcinoma, adenocarcinoma and large cell carcinoma.

Risk factors

A number of factors may increase the risk of lung cancer. Some risk factors can be controlled, for instance, by quitting smoking. Other factors can't be controlled, such as your family history.

Risk factors for lung cancer include:

Smoking

Your risk of lung cancer increases with the number of cigarettes you smoke each day. Your risk also increases with the number of years you have smoked. Quitting at any age can significantly lower your risk of developing lung cancer.

Exposure to secondhand smoke

Even if you don't smoke, your risk of lung cancer increases if you're around people who are smoking. Breathing the smoke in the air from other people who are smoking is called secondhand smoke.

Previous radiation therapy

If you've had radiation therapy to the chest for another type of cancer, you may have an increased risk of developing lung cancer.

Exposure to radon gas

Radon is produced by the natural breakdown of uranium in soil, rock and water. Radon eventually becomes part of the air you breathe. Unsafe levels of radon can build up in any building, including homes.

Exposure to cancer-causing substances

Workplace exposure to cancer-causing substances, called carcinogens, can increase your risk of developing lung cancer. The risk may be higher if you smoke. Carcinogens linked to lung cancer risk include asbestos, arsenic, chromium and nickel.

Family history of lung cancer

People with a parent, sibling or child with lung cancer have an increased risk of the disease.

Complications

Lung cancer can cause complications, such as:

Shortness of breath

People with lung cancer can experience shortness of breath if cancer grows to block the major airways. Lung cancer also can cause fluid to collect around the lungs and heart. The fluid makes it harder for the affected lung to expand fully when you inhale.

Coughing up blood

Lung cancer can cause bleeding in the airway. This can cause you to cough up blood. Sometimes bleeding can become severe. Treatments are available to control bleeding.

Pain

Advanced lung cancer that spreads can cause pain. It may spread to the lining of a lung or to another area of the body, such as a bone. Tell your healthcare professional if you experience pain. Many treatments are available to control pain.

Fluid in the chest

Lung cancer can cause fluid to accumulate in the chest, called pleural effusion. The fluid collects in the space that surrounds the affected lung in the chest cavity, called the pleural space.

Pleural effusion can cause shortness of breath. Treatments are available to drain the fluid from your chest. Treatments can reduce the risk that pleural effusion will happen again.

Cancer that spreads to other parts of the body

Lung cancer often spreads to other parts of the body. Lung cancer may spread to the brain and the bones.

Cancer that spreads can cause pain, nausea, headaches or other symptoms depending on what organ is affected. Once lung cancer has spread beyond the lungs, it's generally not curable. Treatments are available to decrease symptoms and to help you live longer.

Prevention

There's no sure way to prevent lung cancer, but you can reduce your risk if you:

Don't smoke

If you've never smoked, don't start. Talk to your children about not smoking so that they can understand how to avoid this major risk factor for lung cancer. Begin conversations about the dangers of smoking with your children early so that they know how to react to peer pressure.

Stop smoking

Stop smoking now. Quitting reduces your risk of lung cancer, even if you've smoked for years. Talk to your healthcare team about strategies and aids that can help you quit. Options include nicotine replacement products, medicines and support groups.

Avoid secondhand smoke

If you live or work with a person who smokes, urge them to quit. At the very least, ask them to smoke outside. Avoid areas where people smoke, such as bars. Seek out smoke-free options.

Test your home for radon

Have the radon levels in your home checked, especially if you live in an area where radon is known to be a problem. High radon levels can be fixed to make your home safer. Radon test kits are often sold at hardware stores and can be purchased online. For more information on radon testing, contact your local department of public health.

Avoid carcinogens at work

Take precautions to protect yourself from exposure to toxic chemicals at work. Follow your employer's precautions. For instance, if you're given a face mask for protection, always wear it. Ask your healthcare professional what more you can do to protect yourself at work. Your risk of lung damage from workplace carcinogens increases if you smoke.

Eat a diet full of fruits and vegetables

Choose a healthy diet with a variety of fruits and vegetables. Food sources of vitamins and nutrients are best. Avoid taking large doses of vitamins in pill form, as they may be harmful. For instance, researchers hoping to reduce the risk of lung cancer in people who smoked heavily gave them beta carotene supplements. Results showed the supplements increased the risk of cancer in people who smoke.

Exercise most days of the week

If you don't exercise regularly, start out slowly. Try to exercise most days of the week.

Diagnosis

Lung cancer diagnosis often starts with an imaging test to look at the lungs. If you have symptoms that worry you, a healthcare professional might start with an X-ray. If you smoke or used to smoke, you might have an imaging test to look for signs of lung cancer before you develop symptoms.

Testing healthy people for lung cancer

People with an increased risk of lung cancer may consider yearly lung cancer screening using low-dose CT scans. Lung cancer screening is generally offered to people 50 and older who smoked heavily for many years. Screening also is offered to people who have quit smoking in the past 15 years.

Discuss your lung cancer risk with your healthcare professional. Together you can decide whether lung cancer screening is right for you.

Tests to diagnose lung cancer

If your healthcare professional thinks you may have lung cancer, a number of tests can be used to look for cancerous cells and to rule out other conditions.

Tests may include:

Imaging tests. Imaging tests make pictures of the body. They can show the location and size of the lung cancer. Tests might include X-ray, MRI, CT and positron emission tomography, which also is called a PET scan.
Sputum cytology. Sputum is the mucus that is coughed up from the lungs. If you are coughing up sputum, it can be looked at under a microscope. The sputum can sometimes show lung cancer cells.
Biopsy. A biopsy is a procedure to remove a sample of tissue for testing in a lab.

Your healthcare team can perform a lung cancer biopsy several ways. One way is bronchoscopy. During bronchoscopy, a healthcare professional passes a lighted tube with a camera down your throat into your lungs to examine the area. Special tools can be passed through the tube to collect a sample of tissue.

Mediastinoscopy also is an option. During mediastinoscopy, an incision is made at the base of your neck. Surgical tools are then inserted behind your breastbone to take tissue samples from lymph nodes.

Another option is a needle biopsy. In a needle biopsy, your healthcare professional uses X-ray or CT images to guide a needle through the skin on your chest. The needle goes into the lung tissue to collect cells that could be cancerous.

A biopsy sample also may be taken from lymph nodes or other areas where cancer has spread.

Your cancer cells will be carefully tested in a lab to find out what type of lung cancer you have. The results can help determine the likely outcome of your cancer, called the prognosis, and guide your treatment.

Tests to determine the extent of the cancer

If you're diagnosed with lung cancer, you may have other tests to see if the cancer has spread. These tests help your healthcare team find out the extent of your cancer, also called the stage. Cancer staging tests often involve imaging tests. The tests might look for signs of cancer in your lymph nodes or in other parts of your body. Your healthcare team uses the cancer staging test results to help create your treatment plan.

Imaging tests may include MRI, CT, bone scans and PET scan. Not every test is right for every person. Talk with your healthcare professional about which procedures will work for you.

The stages of lung cancer range from 1 to 4. The lowest number means that the cancer is small and only in the lung. As the cancer grows larger or spreads outside of the lungs, the numbers get higher. A stage 4 lung cancer has spread to other areas of the body.

In small cell lung cancer, the stages may be called limited or extensive. In the limited stage, the cancer affects one lung and the area around it. In the extensive stage, the cancer has spread to the other lung or to other parts of the body.

Treatment

Treatment for lung cancer usually begins with surgery to remove the cancer. If the cancer is very large or has spread to other parts of the body, surgery may not be possible. Treatment might start with medicine and radiation instead. Your healthcare team considers many factors when creating a treatment plan. These factors may include your overall health, the type and stage of your cancer, and your preferences.

Some people with lung cancer choose not to have treatment. For instance, you may feel that the side effects of treatment will outweigh the potential benefits. When that's the case, your healthcare professional may suggest comfort care to treat only the symptoms the cancer is causing.

Surgery

During surgery, your surgeon works to remove the lung cancer and some healthy tissue around it. Procedures to remove lung cancer include:

Wedge resection to remove a small section of lung that contains the cancer along with a margin of healthy tissue.
Segmental resection to remove a larger portion of lung, but not an entire lobe.
Lobectomy to remove the entire lobe of one lung.
Pneumonectomy to remove an entire lung.

If you have surgery, your surgeon also may remove lymph nodes from your chest to test them for cancer.

Surgery may be an option if your cancer is only in the lungs. If you have a larger lung cancer, chemotherapy or radiation therapy may be used before surgery to shrink the cancer. Chemotherapy or radiation therapy also may be used after surgery if there's a risk that cancer cells were left behind or that your cancer may come back.

Radiation therapy

Radiation therapy treats cancer with powerful energy beams. The energy can come from X-rays, protons or other sources. During radiation therapy, you lie on a table while a machine moves around you. The machine directs radiation to precise points on your body.

For lung cancer that has spread within the chest, radiation may be used before surgery or after surgery. It's often combined with chemotherapy treatments. If surgery isn't an option, combined chemotherapy and radiation therapy may be your first treatment.

For lung cancers that have spread to other areas of the body, radiation therapy may help relieve symptoms.

Chemotherapy

Chemotherapy treats cancer with strong medicines. Many chemotherapy medicines exist. Most are given through a vein. Some come in pill form. A combination of medicines usually is given in a series of treatments over a period of weeks or months. Breaks in between are used to help you recover.

Chemotherapy is often used after surgery to kill any cancer cells that may remain. It can be used alone or combined with radiation therapy. Chemotherapy also may be used before surgery to shrink cancers and make them easier to remove.

In people with lung cancer that has spread, chemotherapy can be used to relieve pain and other symptoms.

Stereotactic body radiotherapy

Stereotactic body radiotherapy is an intense radiation treatment. This treatment aims beams of radiation from many angles at the cancer. Stereotactic body radiotherapy treatment is typically completed in one or a few treatments. Sometimes this treatment is called stereotactic radiosurgery.

Stereotactic body radiotherapy may be an option for people with small lung cancers who can't have surgery. It also may be used to treat lung cancer that spreads to other parts of the body, including the brain.

Targeted therapy

Targeted therapy for cancer is a treatment that uses medicines that attack specific chemicals in the cancer cells. By blocking these chemicals, targeted treatments can cause cancer cells to die. For lung cancer, targeted therapy may be used for people with cancer that spreads or comes back after treatment.

Some targeted therapies only work in people whose cancer cells have certain DNA changes. Your cancer cells may be tested in a lab to see if these medicines might help you.

Immunotherapy

Immunotherapy for cancer is a treatment with medicine that helps the body's immune system to kill cancer cells. The immune system fights off diseases by attacking germs and other cells that shouldn't be in the body. Cancer cells survive by hiding from the immune system. Immunotherapy helps the immune system cells find and kill the cancer cells.

For lung cancer, immunotherapy might be used after surgery to kill any cancer cells that remain. When surgery isn't an option, immunotherapy might help control the cancer.

Palliative care

Palliative care is a special type of healthcare that helps you feel better when you have a serious illness. If you have cancer, palliative care can help relieve pain and other symptoms. A healthcare team that may include doctors, nurses and other specially trained health professionals provides palliative care. The care team's goal is to improve quality of life for you and your family.

Palliative care specialists work with you, your family and your care team. They provide an extra layer of support while you have cancer treatment. You can have palliative care at the same time you're getting strong cancer treatments, such as surgery, chemotherapy or radiation therapy.

The use of palliative care with other proper treatments can help people with cancer feel better and live longer.

Lifestyle and home remedies

Many people with lung cancer experience shortness of breath. Treatments such as supplemental oxygen and medicines are available to help you feel more comfortable. However, they aren't always enough.

To cope with shortness of breath, it may help to:

Try to relax

Feeling short of breath can be scary. But fear and anxiety only make it harder to breathe. When you begin to feel short of breath, choose an activity that helps you relax. Listen to music, imagine your favorite vacation spot, meditate or say a prayer.

Find a comfortable position

It may help to lean forward when you feel short of breath.

Focus on your breath

When you feel short of breath, focus your mind on your breathing. Instead of trying to fill your lungs with air, concentrate on moving the muscles that control your breathing. Try breathing through pursed lips and pacing your breaths with your activity.

Save your energy for what's important

If you're short of breath, you may become tired easily. Prioritize your tasks for the day so that you can save your energy for what needs to be done.

Tell your healthcare professional if you experience shortness of breath or if your symptoms worsen. There are many other treatments available to relieve shortness of breath.

Alternative medicine

Complementary and alternative lung cancer treatments can't cure your cancer. But complementary and alternative treatments can often be combined with your healthcare team's care to help relieve symptoms.

The American College of Chest Physicians suggests people with lung cancer may find comfort in:

Acupuncture

During an acupuncture session, a trained practitioner inserts small needles into precise points on your body. Acupuncture may relieve pain and ease cancer treatment side effects, such as nausea and vomiting.

Hypnosis

Hypnosis is typically done by a therapist who leads you through relaxation exercises. The therapist may ask you to think pleasing and positive thoughts. Hypnosis may reduce anxiety, nausea and pain in people with cancer.

Massage

During massages, massage therapists use their hands to apply pressure to your skin and muscles. Massage can help relieve anxiety and pain in people with cancer. Some massage therapists are specially trained to work with people who have cancer.

Meditation

Meditation is a time of quiet reflection in which you focus on something. It may be an idea, image or sound. Meditation may reduce stress and improve quality of life in people with cancer.

Yoga

Yoga combines gentle stretching movements with deep breathing and meditation. Yoga may help people with cancer sleep better.

Coping and support

With time, you'll find what helps you cope with the uncertainty and distress of a cancer diagnosis. Until then, you may find that it helps to:

Learn enough about lung cancer to make decisions about your care

Ask your healthcare team about your cancer, including your test results, treatment options and, if you like, your prognosis. As you learn more about lung cancer, you may become more confident in making treatment decisions.

Keep friends and family close

Keeping your close relationships strong will help you deal with your lung cancer. Friends and family can provide the practical support you'll need, such as helping take care of your home if you're in the hospital. And they can serve as emotional support when you feel overwhelmed by having cancer.

Find someone to talk with

Find someone who is willing to listen to you talk about your hopes and fears. This may be a friend or family member. The concern and understanding of a counselor, medical social worker, clergy member or cancer support group also may be helpful.

Ask your healthcare team about support groups in your area. Other sources of information include the National Cancer Institute and the American Cancer Society.

Preparing for an appointment

Make an appointment with a doctor or other healthcare professional if you have any symptoms that worry you.

If your healthcare professional suspects that you have lung cancer, you'll likely be referred to a specialist. Specialists who treat lung cancer may include:

Oncologists. Doctors who specialize in treating cancer.
Pulmonologists. Doctors who diagnose and treat lung diseases.
Radiation oncologists. Doctors who use radiation to treat cancer.
Thoracic surgeons. Surgeons who operate on the lungs.
Palliative care specialists. Doctors who treat signs and symptoms of cancer and cancer treatment.

Because appointments can be brief, it's a good idea to be prepared. Here's some information to help you get ready.

What you can do

Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance, such as restrict your diet.
Write down symptoms you're experiencing, including any that may not seem related to the reason for which you scheduled the appointment.
Write down key personal information, including major stresses or recent life changes.
Make a list of all medicines, vitamins or supplements you're taking and the doses. Or you may prefer to bring your medicine bottles to your appointment.
Gather your medical records. If you've had a chest X-ray or a scan done by a different healthcare professional, try to get that file and bring it to your appointment.
Consider taking a family member or friend along. Sometimes it can be difficult to remember all the information provided during an appointment. Someone who accompanies you may remember something that you missed or forgot.
Write down questions to ask your healthcare team.

Questions to ask if you've been diagnosed with lung cancer

Your time with your healthcare team is limited, so preparing a list of questions can help you make the most of your time together. List your questions from most important to least important in case time runs out. For lung cancer, some basic questions to ask include:

What type of lung cancer do I have?
May I see the chest X-ray or CT scan that shows my cancer?
What is causing my symptoms?
What is the stage of my lung cancer?
Will I need more tests?
Should my lung cancer cells be tested for gene changes that may determine my treatment options?
Has my cancer spread to other parts of my body?
What are my treatment options?
Will any of these treatment options cure my cancer?
What are the potential side effects of each treatment?
Is there one treatment that you think is best for me?
Is there a benefit if I quit smoking now?
What advice would you give a friend or family member in my situation?
What if I don't want treatment?
Are there ways to relieve the symptoms I'm experiencing?
Can I enroll in a clinical trial?
Should I see a specialist? What will that cost, and will my insurance cover it?
Are there brochures or other material that I can take with me? What websites do you recommend?

Don't hesitate to ask other questions.

What to expect from your doctor

Be prepared to answer questions, such as:

When did you first begin experiencing symptoms?
Have your symptoms been ongoing or occasional?
How severe are your symptoms?
Do you wheeze when breathing?
Do you have a cough that feels like you're clearing your throat?
Have you ever been diagnosed with emphysema or chronic obstructive pulmonary disease?
Do you take medicines for shortness of breath?
What, if anything, seems to improve your symptoms?
What, if anything, appears to worsen your symptoms?