Most people with early lung cancer do not have any symptoms, so only a small number of lung cancers are found at an early stage. When lung cancer is found early, it is often because of tests that were being done for something else.

Screening tests for lung cancer

Screening is the use of tests or exams to find a disease like cancer in people who don't have any symptoms. Because lung cancer often spreads beyond the lungs before it causes symptoms, a good screening test to find lung cancer early could save many lives.

Chest x-rays and checking sputum (spit) under a microscope to look for cancer cells have been studied for many years. Studies have shown that this kind of screening does not find many lung cancers early enough to improve a person's chance for a cure. For this reason, lung cancer screening is not usually advised even for people at higher risk, such as those who smoke.

A new x-ray method called spiral CT scanning has shown some promise in finding early lung cancer in smokers and former smokers. But we don't yet know if this test will lower the chances of dying from lung cancer. One major problem is that the test finds a lot of things that turn out not to be cancer. This can lead to many more tests and even surgery.

To find out how useful this test might be, a large study is going on now. It is called the National Lung Screening Trial (NLST). When the results come out, we will have a better idea whether spiral CT scanning will catch lung cancer early enough to save lives.

Until then, people who smoke, who smoked in the past, or who have been exposed to other people's smoke, as well as those who have worked around materials that increase the risk for lung cancer need to be aware of their lung cancer risk. They should talk to their doctors about their chances of getting lung cancer and the pros and cons of lung cancer screening. If, after talking all of this over with your doctor, you decide in favor of testing, be sure to choose a place that has experience in lung scanning and a good program for testing people at high risk.

People who smoke should keep in mind that the best way to avoid dying from lung cancer is to stop smoking.

Common signs and symptoms of lung cancer

Most lung cancers do not cause symptoms until they have spread, but you should report any of the following problems to a doctor right away. Often these problems are caused by something other than cancer. If lung cancer is found, getting treatment right away might mean treatment would work better. The most common symptoms of lung cancer are:

• a cough that does not go away
• chest pain, often made worse by deep breathing, coughing, or laughing
• hoarseness
• weight loss and loss of appetite
• coughing up blood or rust-colored sputum (spit or phlegm)
• shortness of breath
• feeling tired or weak
• infections such as bronchitis and pneumonia that keep coming back
• new onset of wheezing

When lung cancer spreads to distant organs, it may cause:

• bone pain
• weakness or numbness of the arms or legs
• headache, dizziness, or seizure
• yellow coloring of the skin and eyes (jaundice)
• lumps near the surface of the body, caused by cancer spreading to the skin or to lymph nodes in the neck or above the collarbone

Some lung cancers can cause a group of very specific symptoms. These are often described as syndromes.

Horner syndrome

Cancers of the top part of the lungs (sometimes called Pancoast tumors) may damage a nerve that passes from the upper chest into your neck. This can cause severe shoulder pain. Sometimes these tumors also cause a group of symptoms called Horner syndrome:

• drooping or weakness of one eyelid
• having a smaller pupil (dark part in the center of the eye) in the same eye
• reduced or absent sweating on the same side of the face

Conditions other than lung cancer can also cause Horner syndrome.

Paraneoplastic syndromes

Some lung cancers may make hormone-like substances that enter the bloodstream and cause problems with distant tissues and organs, even though the cancer has not spread to those tissues or organs. These problems are called paraneoplastic syndromes. Sometimes these syndromes may be the first symptoms of lung cancer. Because the symptoms affect other organs, patients and their doctors may suspect at first that something other than lung cancer is causing them.

The most common paraneoplastic syndromes caused by non-small cell lung cancer are:

• high blood calcium levels which can cause frequent urination, constipation, nausea, vomiting, weakness, dizziness, confusion, and other nervous system problems

• too much growth of certain bones, like those in the finger tips, which is often painful

• blood clots

• breast growth in men

Most of the symptoms listed here are more likely to be caused by something other than lung cancer. Still, if you have any of these problems, you should see a doctor right away.

If your doctor thinks you might have lung cancer

After asking questions about your health and doing a physical exam, your doctor might want to do some of the following tests:

Imaging tests

There are a number of different tests that can make pictures of the inside of your body. Some of these are used to find lung cancer, to see if it has spread, or to find out whether treatment is working.

Chest x-ray: This is the first test your doctor will do to look for any spots on the lungs. It is a plain x-ray of your chest. If the x-ray is normal, you most likely do not have lung cancer. If anything does not look normal the doctor may order more tests.

CT scan (computed tomography): A CT (or CAT) scan is a special kind of x-ray. Instead of taking just one picture, the CT scanner takes many pictures as it moves around you. A computer then combines these pictures into a picture of a slice of your body.

Before the CT scan, you may be asked to drink a special liquid or you may have an IV (intravenous) line through which you are given a contrast dye. This helps better outline structures in your body. The dye may cause some flushing (a feeling of warmth, especially in the face). Some people are allergic and get hives. Rarely, more serious reactions like trouble breathing or low blood pressure can happen. Be sure to tell the doctor if you have any allergies or if you have ever had a reaction to any contrast material used for x-rays. CT scans take longer than normal x-rays, but they are getting faster all the time.

The CT scan will give the doctor precise information about the size, shape, and place of a tumor. It can also help find enlarged lymph nodes that might contain cancer. CT scans are used to find tumors in the adrenal glands, liver, brain, and other organs, too.

CT guided needle biopsy: A CT scan can also be used to guide a biopsy needle right into a place that might have cancer. To have this done, you stay on the CT scanning table while the doctor moves a biopsy needle through the skin and into the mass. A biopsy sample is then removed and looked at under a microscope.

MRI scan (magnetic resonance imaging): Like CT scans, MRI scans give detailed pictures of soft tissues in the body. But MRI scans use radio waves and strong magnets instead of x-rays. MRI scans take longer than x-rays -- often up to an hour. Also, you have to be placed inside a tube-like machine, which upsets some people. Newer, open MRI machines can sometimes help with this if needed. MRI scans are useful in finding lung cancer that has spread to the brain or spinal cord.

PET scan (positron emission tomography): PET scans use a form of sugar that contains a radioactive atom. Cancer cells in the body absorb large amounts of the sugar. A special camera can then spot the radioactivity. This test can show whether the cancer has spread to the lymph nodes. It is also helpful in telling whether a spot on your chest x-ray is cancer. PET scans are also useful when the doctor thinks the cancer has spread, but doesn't know where. Newer machines combine a CT and a PET scan to even better pinpoint tumors.

Bone scan: For a bone scan a small amount of radioactive substance is put into your vein. The amount used is very low and it causes no long-term effects. This substance builds up in areas of bone that may not be normal because of cancer. These will show up as dense, gray to black areas, called "hot spots." While these areas may suggest the presence of metastatic cancer, other problems can also cause hot spots.

PET scans are often done in people with non-small cell lung cancer. They can usually show the spread of cancer to bones, so bone scans aren't needed very often. Bone scans are done mainly when there is reason to think the cancer may have spread to the bones (maybe because of symptoms) and other test results aren't clear.

Tests of tissues and cells

The tests described below can be used to be sure that something seen on an imaging test is really lung cancer. These tests are also used to decide the exact type of lung cancer and how far it may have spread.

A doctor (called a pathologist) who is an expert in using lab tests to diagnose diseases like cancer will look at the cells under a microscope. If you have any questions about your pathology results or any other tests, be sure and ask your doctor. If needed, you can get a second opinion about your report (called a pathology review) by having your tissue sample sent to a pathologist at another lab.

Sputum cytology: A sample of mucus you cough up from the lungs (called phlegm: pronounced "flem") is looked at under a microscope to see if cancer cells are present.

Fine needle biopsy (FNA): A long, thin (fine) needle is used to remove a sample of cells from the area that may be cancer. An imaging test (like a CT scan) is used to guide the needle to the right spot. The sample is looked at in the lab to see if there are cancer cells in it.

Bronchoscopy: A lighted, flexible tube (called a bronchoscope) is passed through the mouth into the bronchi. The mouth and throat are sprayed first with a numbing medicine. You may also be given medicine through an intravenous (IV) line to make you feel relaxed. This test can help find tumors, or it can be used to take samples of tissue or fluids to see if cancer cells are present

Endobronchial ultrasound: Ultrasound is a test that uses sound waves to make pictures of the inside of your body. For endobronchial ultrasound, a bronchoscope (a thin, lighted, flexible tube) is fitted with an ultrasound device at its tip and is passed down into the windpipe. If areas of concern (such as enlarged lymph nodes) are seen on the ultrasound, a hollow needle can be passed through the bronchoscope and guided by ultrasound into the area to take biopsy samples. The samples are then looked at under a microscope to see if cancer cells are present.

Endoscopic esophageal ultrasound: This test is much like an endobronchial ultrasound, except that an endoscope (a lighted, flexible tube) is used. It is passed down the throat and into the esophagus (the swallowing tube that connects the mouth to the stomach). The esophagus lies just behind the windpipe. This test is done with numbing medicine (local anesthesia) and drugs to make you sleepy (light sedation).

Ultrasound images taken from inside the esophagus can help find large lymph nodes inside the chest that might contain lung cancer. If areas of concern (such as enlarged lymph nodes) are seen on the ultrasound, a hollow needle can be passed through the endoscope to get biopsy samples of them. The samples are then looked at under a microscope to see if they contain cancer cells.

Mediastinoscopy and mediastinotomy: Both of these tests allow the doctor to look at and sample the structures in the area between the lungs (this area is called the mediastinum) and behind the breast bone. These tests are done in an operating room while you are in a deep sleep (under general anesthesia). The main difference between them is in the place and size of the cut (incision) needed.

Thoracentesis and thoracoscopy: These tests are done to check whether fluid around the lungs is caused by cancer or by some other medical problem, such as heart failure or an infection. For thoracentesis, the skin is numbed and a needle is placed between the ribs to drain the fluid. The fluid is checked for cancer cells.

Drugs are used to put you to sleep, and a small cut is made in your chest for a thoracoscopy. This test uses a thin, lighted tube connected to a video camera and screen to look at the space between the lungs and the chest wall. By doing this, the doctor can see small tumors on the lung or lining of the chest wall and can take out pieces of tissue to be looked at under the microscope. Thoracoscopy can also be used to sample lymph nodes and fluid and to tell whether a tumor is growing into nearby tissues or organs.

Lab tests and other tests

Samples from biopsies or other tests are sent to a lab. There, a doctor looks at the samples under a microscope to find out if they contain cancer and if so, what type of cancer it is. Special tests may be needed to help classify the cancer. Cancers from other organs can spread to the lungs. It's very important to find out where the cancer started, because treatment is different for different types of cancer.

Blood tests: Blood tests are not used to find lung cancer, but they are done to get a sense of a person's overall health. A complete blood count (CBC) shows whether your blood has the right number of different cell types. This test will be done often if you are treated with chemo because these drugs can affect the blood-forming cells of the bone marrow. Other blood tests can spot problems in different organs such as the kidneys, liver, and bones.

Pulmonary function tests: Pulmonary function tests (PFTs) are often done after a lung cancer has been found. These tests show how well your lungs are working. This is especially important if surgery might be an option in treating the cancer. These tests can give the surgeon an idea of how much lung can be removed or if surgery is a good option at all.

Last Medical Review: 11/03/2009
Last Revised: 11/03/2009