Since most people with early lung cancer do not have any symptoms, 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 (such as 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. These 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.

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

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 secondhand 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 screening with a good program to evaluate 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 your doctor right away. Often these problems are caused by something other than cancer. If lung cancer is found, getting treatment right away might mean your cancer could be cured. Or you could live longer with a better quality of life. 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 bloody or rust-colored sputum (spit or phlegm)
• Shortness of breath
• Feeling weak or tired
• 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

If you have any of these symptoms, you should see a doctor right away.

Some lung cancers can cause a group of symptoms called 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.

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 an image 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 "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 ever had a reaction to any contrast material used for x-rays.

CT scans take longer than regular x-rays. You need to lie still on a table while they are being done. You might feel a bit confined by the ring-shaped machine you have to lie in while the pictures are being taken. Spiral CT (also known as helical CT) is now available in many medical centers. This type of CT scan uses a faster machine.

The CT scan will give the doctor exact information about the size, shape, and place of a tumor. It can also help find swollen lymph nodes that might contain cancer. CT scans are also used to find tumors in other organs that might be the spread of lung cancer.

CT guided needle biopsy: In cases where the doctor suspects that the cancer lies deep within the body, a CT scan can be used to guide a biopsy needle right into the that place. For this, you stay on the CT scanning table while the doctor moves a biopsy needle through the skin and toward the mass. Once the doctor can see that the needle is within the mass, a piece of it is removed and looked at under a microscope.

MRI scan (magnetic resonance imaging): MRI scans use radio waves and strong magnets instead of x-rays to take pictures. 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 take in 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 be seen on the bone scan pictures 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. Bone scans are only done in patients with lung cancer when other test results or symptoms suggest that the cancer has spread to the bones.

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 find out 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. The results will be described in a pathology report, which should take about a week. If you have any questions about your results or any other tests, be sure and ask your doctor. If needed, you can get a second opinion by having your tissue sample sent to a pathologist at another lab.

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

Fine needle biopsy (FNA): To do this, a long, thin (fine) needle is put into the place in the lung that might be cancer to remove a sample of cells. (The skin where the needle is to be put in may first be numbed with medicine.) The sample is looked at in the lab to see whether there are cancer cells. An FNA biopsy may also be done to take samples of lymph nodes around the windpipe (trachea) and the larger tubes that carry air to the lungs (bronchi).

Sometimes, air may leak out of the lung at the biopsy site and into the space between the lung and the chest wall. This can cause part of the lung to collapse and may cause trouble breathing. This often gets better without any treatment. If not, it is treated by putting a small tube into the chest space and sucking out the air over a day or two, after which it heals on its own.

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 parts 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 swollen 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 there are cancer cells.

Endoscopic esophageal ultrasound (EUS): This test is much like an endobronchial ultrasound, except an endoscope (a lighted, flexible tube) is used. It is passed down the throat and into the esophagus (the swallowing tube that connects the throat to the stomach). The esophagus lies just behind the windpipe. This test is done with numbing medicine (local anesthesia) and drugs are used to help you relax (this is called 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 swollen 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. They are done in an operating room while you are in a deep sleep (under general anesthesia). The main difference between the 2 is in the place and size of the cut (incision) needed to look into this area.

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 hollow needle is placed between the ribs to drain the fluid. The fluid is checked for cancer cells. Thoracoscopy 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 any cancer deposits on the lung or lining of the chest wall and take out small 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.

Bone marrow biopsy: For this test you lie on your side or on your belly. The skin over the back of your hip is cleaned. After the area is numbed, a needle is used to remove a small piece of the hip bone and some bone marrow. Even with the numbing medicine, most patients still have some brief pain when the sample is removed. The sample is checked for cancer cells. This is done mostly to help find if small cell lung cancer has spread to the bones.

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, so it is 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 correct number of different cell types. This test will be done often if you are treated with chemotherapy 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 whether surgery is a good option at all.

Last Medical Review: 11/18/2009
Last Revised: 11/18/2009