How is mesothelioma found?

As a rule, a chest x-ray is not useful in finding mesothelioma early. One test being studied is a blood test. This test measures the blood levels of certain substances that are higher in people who have mesothelioma. But right now blood tests are used mainly to follow the course of the disease in people who are already known to have mesothelioma.

Symptoms of mesothelioma

Most of the time mesothelioma is found when a person goes to a doctor because of symptoms. Early symptoms can be very general and are often ignored. Most people with this type of cancer have symptoms for only a few months before the cancer is found.

Symptoms of pleural mesothelioma (lining of the chest) can include:

· Pain in the lower back or at the side of the chest

· Shortness of breath

· Trouble swallowing

· Hoarseness

· Cough

· Fever

· Sweating

· Tiredness

· Weight loss

· Swelling of the face and arms

· Muscle weakness

Symptoms of peritoneal mesothelioma (lining of the abdominal cavity) can include:

· Belly pain

· Weight loss

· Nausea and vomiting

· Fluid or swelling in the abdomen (belly)

Of course, these same symptoms can also be caused by other problems. But if you have worked with asbestos and you have any of these symptoms, you should see a doctor right away.

If there is reason to think you might have mesothelioma, the doctor will ask you questions about your health and do a complete physical exam. The exam can help tell if you have fluid in the chest, belly, or around the heart. This fluid can be a sign of mesothelioma. Then one or more of the tests listed below can be used to find out if you have cancer.

Imaging tests

These tests allow the doctor to see pictures of the inside of your body. These tests might be done for a number of reasons, such as to help find an area that might be cancer, to learn how far cancer has spread, and to see if treatment is working.

Chest x-ray: X-rays might show thickening of the lining of the lungs or other changes caused by asbestos. They can also show changes that may suggest mesothelioma.

CT scan: A CT scan (or CAT scan) is like an x-ray but it gives detailed cross-sectional pictures of your body. Instead of taking one picture, a CT scanner takes many pictures as it moves around you. A computer then combines these pictures to show slices of your body.

CT scans are often used to help decide if you have mesothelioma and to help find the exact place of the cancer. They can also help find out much the cancer has spread. Before any pictures are taken, you may be asked to drink a liquid that helps outline your intestines (gut). You may also get an IV (intravenous) line which is used to put a different kind of contrast dye into your blood. This helps better outlines parts of in your body.

Some people are allergic to the dye and get hives, a flushed feeling, or, rarely, more serious problems like trouble breathing and low blood pressure. Be sure to tell your doctor if you have ever had a problem from any dye used for x-rays.

CT scans take longer than regular x-rays, and you need to lie still on a table while they are being done. During the test, the table moves in and out of the scanner, a ring-shaped machine that goes around the table.

PET scan: A PET scan uses glucose (a form of sugar) that contains a radioactive substance. Cancer cells in the body take in large amounts of the radioactive sugar and a special camera can find these radioactive spots. This test can help tell whether a thickening of the tissues is cancer or just scar tissue. It can also show the spread of cancer. Some newer machines are able to do both a PET and CT scan at the same time.

MRI scan: This test uses radio waves and strong magnets instead of x-rays to take pictures. It gives a very detailed picture of your insides. MRI scans may be useful in looking at the thin band of breathing muscle below the lungs (the diaphragm). Mesothelioma can spread there.

A contrast dye might be used just as with CT scans. MRI scans take longer than CT scans -- often up to an hour. Also, you are placed inside a narrow tube, which is confining and can upset people with a fear of enclosed spaces. The machine makes a thumping noise, and some places will give you headphones with music to block it out.

Blood tests

Blood levels of certain substances are often high in people with mesothelioma. But so far, these blood tests have proven more useful in people who already have mesothelioma to follow their progress during and after treatment. Other blood tests will be done to check the blood cell counts and levels of certain chemicals in the blood. These tests can give the doctor an idea of how much the disease has spread, and how well organs like the liver and kidneys are working.

Tests of fluid and tissue samples

If you have a build-up of fluid in the body that may be caused by mesothelioma, a sample of this fluid can be taken. The skin is numbed and a needle is put through the skin into the fluid, which is drawn out and sent to the lab. The fluid is tested to see if there are cancer cells in it.

This test has different names depending on where the fluid is:

· Thoracentesis removes fluid from the chest cavity.

· Paracentesis removes fluid from the abdomen (belly).

· Pericardiocentesis removes fluid from the sac around the heart.

Finding cancer cells tells the doctor that cancer is present, but not finding any cancer cells in the fluid does not always mean there is no cancer. In many cases, doctors need to get a sample of the tissue (called a biopsy) to find out if you have mesothelioma.

Biopsy methods

In a biopsy, a small amount of tissue of fluid is taken out and looked at under a microscope to see whether it contains cancer.

Needle biopsy: Tumors in the chest are sometimes sampled by needle biopsy. A long, hollow needle is passed through the skin, between the ribs, into the chest, and into the tumor. A small sample can be removed to be looked at under the microscope. But sometimes the sample is not be big enough to tell for sure whether there is cancer. If this happens, another kind of biopsy may be needed.

Endoscopic biopsies: An endoscope (scope) is a thin, tube-like tool used to look inside the body. It has a light and a lens (or camera) and tools that can be used to remove tissue that looks like it may be cancer. There are a number of different types of scopes. They are often named after the part of the body that they are used to examine, for instance:

· A thoracoscope is used to look inside the chest

· A mediastinoscope is used to look at the space between the lungs

· A bronchoscope is used to look at the lining of the lungs

· A laparoscope is used to look inside the belly

Open surgical biopsy: In some cases, surgery may be needed to get a large enough tissue sample. This allows the doctor to remove a larger sample of tumor or, sometimes, the whole tumor.

Testing the samples in the lab

No matter which approach is used to get them, biopsy and fluid samples are sent to the pathology lab. There, a doctor will look at them under a microscope and do other tests to decide whether cancer is present (and if so, what type of cancer it is). It is often hard to tell whether it is mesothelioma by just looking at the cells (or even tissue) from the fluid around the lungs, stomach, or heart. So special lab tests that look at things like proteins may be done, too.

Pulmonary function tests

Pulmonary function tests (PFTs) may be done after mesothelioma is found to see how well your lungs are working. This is important if you might need surgery to take out part or all of a lung. to the doctors need to know how well the lungs are working before the surgery. These tests can give the doctor an idea of how much lung can safely be removed. For PFTs, you breathe in and out through a tube that is connected to a machine that measures lung function.

Thanks to American Cancer Society for this article