Overview

Lung cancer is a type of cancer that begins in the lungs. Your lungs are two spongy organs in your chest that take in oxygen when you inhale and release carbon dioxide when you exhale.

Lung cancer is the leading cause of cancer deaths in the United States, among both men and women. Lung cancer claims more lives each year than do colon, prostate, ovarian and breast cancers combined.

People who smoke have the greatest risk of lung cancer, though lung cancer can also occur in people who have never smoked. The risk of lung cancer increases with the length of time and number of cigarettes you've smoked. If you quit smoking, even after smoking for many years, you can significantly reduce your chances of developing lung cancer.

Lung cancer care at Mayo Clinic

Source: http://www.mayoclinic.com

Symptoms

Lung cancer typically doesn't cause signs and symptoms in its earliest stages. Signs and symptoms of lung cancer typically occur only when the disease is advanced.

Signs and symptoms of lung cancer may include:

• A new cough that doesn't go away
• Coughing up blood, even a small amount
• Shortness of breath
• Chest pain
• Hoarseness
• Losing weight without trying
• Bone pain
• Headache

When to see a doctor

Make an appointment with your doctor if you have any persistent signs or symptoms that worry you.

If you smoke and have been unable to quit, make an appointment with your doctor. Your doctor can recommend strategies for quitting smoking, such as counseling, medications and nicotine replacement products.

Source: http://www.mayoclinic.com

Causes

Smoking causes the majority of lung cancers — both in smokers and in people exposed to secondhand smoke. But lung cancer also occurs in people who never smoked and in those who never had prolonged exposure to secondhand smoke. In these cases, there may be no clear cause of lung cancer.

How smoking causes lung cancer

Doctors believe smoking causes lung cancer by damaging the cells that line the lungs. When you inhale cigarette smoke, which is full of cancer-causing substances (carcinogens), changes in the lung tissue begin almost immediately.

At first your body may be able to repair this damage. But with each repeated exposure, normal cells that line your lungs are increasingly damaged. Over time, the damage causes cells to act abnormally and eventually cancer may develop.

Types of lung cancer

Doctors divide lung cancer into two major types based on the appearance of lung cancer cells under the microscope. Your doctor 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 occurs almost exclusively in heavy smokers and is less common than non-small cell lung cancer.
• Non-small cell lung cancer. Non-small cell lung cancer is an umbrella term for several types of lung cancers that behave in a similar way. Non-small cell lung cancers include squamous cell carcinoma, adenocarcinoma and large cell carcinoma.

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Diagnosis

Testing healthy people for lung cancer

People with an increased risk of lung cancer may consider annual lung cancer screening using low-dose CT scans. Lung cancer screening is generally offered to people 55 and older who smoked heavily for many years and are otherwise healthy.

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

Tests to diagnose lung cancer

If there's reason to think that you may have lung cancer, your doctor can order a number of tests to look for cancerous cells and to rule out other conditions.

Tests may include:

• Imaging tests. An X-ray image of your lungs may reveal an abnormal mass or nodule. A CT scan can reveal small lesions in your lungs that might not be detected on an X-ray.
• Sputum cytology. If you have a cough and are producing sputum, looking at the sputum under the microscope can sometimes reveal the presence of lung cancer cells.

• Tissue sample (biopsy). A sample of abnormal cells may be removed in a procedure called a biopsy.

  Your doctor can perform a biopsy in a number of ways, including bronchoscopy, in which your doctor examines abnormal areas of your lungs using a lighted tube that's passed down your throat and into your lungs; mediastinoscopy, in which an incision is made at the base of your neck and surgical tools are inserted behind your breastbone to take tissue samples from lymph nodes; and needle biopsy, in which your doctor uses X-ray or CT images to guide a needle through your chest wall and into the lung tissue to collect suspicious cells.

  A biopsy sample may also be taken from lymph nodes or other areas where cancer has spread, such as your liver.

Careful analysis of your cancer cells in a lab will reveal what type of lung cancer you have. Results of sophisticated testing can tell your doctor the specific characteristics of your cells that can help determine your prognosis and guide your treatment.

Tests to determine the extent of the cancer

Once your lung cancer has been diagnosed, your doctor will work to determine the extent (stage) of your cancer. Your cancer's stage helps you and your doctor decide what treatment is most appropriate.

Staging tests may include imaging procedures that allow your doctor to look for evidence that cancer has spread beyond your lungs. These tests include CT, MRI, positron emission tomography (PET) and bone scans. Not every test is appropriate for every person, so talk with your doctor about which procedures are right for you.

The stages of lung cancer are indicated by Roman numerals that range from 0 to IV, with the lowest stages indicating cancer that is limited to the lung. By stage IV, the cancer is considered advanced and has spread to other areas of the body.

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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 can also cause fluid to accumulate around the lungs, making it harder for the affected lung to expand fully when you inhale.
• Coughing up blood. Lung cancer can cause bleeding in the airway, which can cause you to cough up blood (hemoptysis). Sometimes bleeding can become severe. Treatments are available to control bleeding.
• Pain. Advanced lung cancer that spreads to the lining of a lung or to another area of the body, such as a bone, can cause pain. Tell your doctor if you experience pain, as many treatments are available to control pain.

• Fluid in the chest (pleural effusion). Lung cancer can cause fluid to accumulate in the space that surrounds the affected lung in the chest cavity (pleural space).

  Fluid accumulating in the chest can cause shortness of breath. Treatments are available to drain the fluid from your chest and reduce the risk that pleural effusion will occur again.

• Cancer that spreads to other parts of the body (metastasis). Lung cancer often spreads (metastasizes) to other parts of the body, such as the brain and the bones.

  Cancer that spreads can cause pain, nausea, headaches, or other signs and 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 signs and symptoms and to help you live longer.

Source: http://www.mayoclinic.com

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 doctor about strategies and stop-smoking aids that can help you quit. Options include nicotine replacement products, medications and support groups.
• Avoid secondhand smoke. If you live or work with a smoker, urge him or her to quit. At the very least, ask him or her to smoke outside. Avoid areas where people smoke, such as bars and restaurants, and 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 remedied to make your home safer. For information on radon testing, contact your local department of public health or a local chapter of the American Lung Association.
• 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 doctor 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 heavy smokers gave them beta carotene supplements. Results showed the supplements actually increased the risk of cancer in smokers.
• Exercise most days of the week. If you don't exercise regularly, start out slowly. Try to exercise most days of the week.

Alternative medicine

Complementary and alternative lung cancer treatments can't cure your cancer. But complementary and alternative treatments can often be combined with your doctor's care to help relieve signs and 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, but there's no evidence that acupuncture has any effect on your cancer.
• Hypnosis. Hypnosis is typically done by a therapist who leads you through relaxation exercises and asks you to think pleasing and positive thoughts. Hypnosis may reduce anxiety, nausea and pain in people with cancer.
• Massage. During a massage, a massage therapist uses his or her 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, such as 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.

Source: http://www.mayoclinic.com

Lifestyle and home remedies

Coping with shortness of breath

Many people with lung cancer experience shortness of breath at some point in the course of the disease. Treatments such as supplemental oxygen and medications are available to help you feel more comfortable, but 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, try to manage the fear by choosing 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 diaphragm. 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. Cut out the nonessential tasks from your day so that you can save your energy for what needs to be done.

Tell your doctor if you experience shortness of breath or if your symptoms worsen, as there are many other treatments available to relieve shortness of breath.

Source: http://www.mayoclinic.com

Coping and support

A diagnosis of cancer can be overwhelming. With time you'll find ways to cope with the distress and uncertainty of cancer. Until then, you may find it helps to:

• Learn enough about lung cancer to make decisions about your care. Ask your doctor about your lung cancer, including your 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 house if you're in the hospital. And they can serve as emotional support when you feel overwhelmed by cancer.

• Find someone to talk with. Find a good listener 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 doctor about support groups in your area. Or check with local and national cancer organizations, such as the National Cancer Institute or the American Cancer Society.

Source: http://www.mayoclinic.com

Risk factors

A number of factors may increase your risk of lung cancer. Some risk factors can be controlled, for instance, by quitting smoking. And 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 and 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 exposed to secondhand smoke.
• Exposure to radon gas. Radon is produced by the natural breakdown of uranium in soil, rock and water that eventually becomes part of the air you breathe. Unsafe levels of radon can accumulate in any building, including homes.
• Exposure to asbestos and other carcinogens. Workplace exposure to asbestos and other substances known to cause cancer — such as arsenic, chromium and nickel — also can increase your risk of developing lung cancer, especially if you're a smoker.
• Family history of lung cancer. People with a parent, sibling or child with lung cancer have an increased risk of the disease.

Source: http://www.mayoclinic.com