Mesothelioma

Mesothelioma: General Information

Mesothelioma

Malignant mesothelioma is a disease in which malignant (cancer) cells form in the lining of the chest or abdomen.

Malignant mesothelioma is a disease in which malignant (cancer) cells are found in the pleura (the thin layer of tissue that lines the chest cavity and covers the lungs) or the peritoneum (the thin layer of tissue that lines the abdomen and covers most of the organs in the abdomen).

Being exposed to asbestos can affect the risk of developing malignant mesothelioma.

Many people with malignant mesothelioma have worked or lived in places where they inhaled or swallowed asbestos. After being exposed to asbestos, it usually takes a long time for malignant mesothelioma to occur. Other risk factors for malignant mesothelioma include the following:

Living with a person who works near asbestos.
Being exposed to a certain virus.

Possible signs of malignant mesothelioma include shortness of breath and pain under the rib cage.

Sometimes the cancer causes fluid to collect around the lung or in the abdomen. These symptoms may be caused by the fluid or malignant mesothelioma. Other conditions may cause the same symptoms. A doctor should be consulted if any of the following problems occur:

Trouble breathing.
Pain under the rib cage.
Pain or swelling in the abdomen.
Lumps in the abdomen.
Weight loss for no known reason.

Tests that examine the inside of the chest and abdomen are used to detect (find) and diagnose malignant mesothelioma.

Sometimes it is hard to tell the difference between malignant mesothelioma and lung cancer. The following tests and procedures may be used:

Physical exam and history: An exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else that seems unusual. A history of the patient’s health habits, exposure to asbestos, past illnesses and treatments will also be taken.
Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
Complete blood count (CBC): A procedure in which a sample of blood is drawn and checked for the following:
- The number of red blood cells, white blood cells, and platelets.
- The amount of hemoglobin (the protein that carries oxygen) in the red blood cells.
- The portion of the blood sample made up of red blood cells.

Sedimentation rate: A procedure in which a sample of blood is drawn and checked for the rate at which the red blood cells settle to the bottom of the test tube.
Biopsy: The removal of cells or tissues from the pleura or peritoneum so they can be viewed under a microscope by a pathologist to check for signs of cancer. Procedures used to collect the cells or tissues include the following:
- Fine-needle aspiration biopsy: The removal of part of a lump, suspicious tissue, or fluid, using a thin needle. This procedure is also called a needle biopsy.
- Thoracoscopy: An incision (cut) is made between two ribs and a thoracoscope (a thin, lighted tube) is inserted into the chest.
- Peritoneoscopy: An incision (cut) is made in the abdominal wall and a peritoneoscope (a thin, lighted tube) is inserted into the abdomen.
- Laparotomy: An incision (cut) is made in the wall of the abdomen to check the inside of the abdomen for signs of disease.
- Thoracotomy: An incision (cut) is made between two ribs to check inside the chest for signs of disease.
Bronchoscopy: A procedure to look inside the trachea and large airways in the lung for abnormal areas. A bronchoscope (a thin, lighted tube) is inserted through the nose or mouth into the trachea and lungs. Tissue samples may be taken for biopsy.
Cytologic exam: An exam of cells under a microscope (by a pathologist) to check for anything abnormal. For mesothelioma, fluid is taken from around the lungs or from the abdomen. A pathologist checks the cells in the fluid.

Certain factors affect prognosis (chance of recovery) and treatment options.

The stage of the cancer.

The size of the tumor.

Whether the tumor can be removed completely by surgery.

The amount of fluid in the chest or abdomen.

The patient's age and general health, including lung and heart health.

The type of mesothelioma cancer cells and how they look under a microscope.

Whether the cancer has just been diagnosed or has recurred (come back).

Stages

After malignant mesothelioma has been diagnosed, tests are done to find out if cancer cells have spread to other parts of the body.

The process used to find out if cancer has spread outside the pleura or peritoneum is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the spread of the cancer in order to plan treatment. The following tests and procedures may be used in the staging process:

Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
CT scan (CAT scan): A procedure that makes a series of detailed pictures of the chest and abdomen, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of the chest or abdomen. This procedure is also called nuclear magnetic resonance imaging (NMRI).

The stages of malignant mesothelioma are divided into two groups.

Malignant mesothelioma stages are grouped into localized and advanced.

Localized malignant mesothelioma (stage I)

In localized malignant mesothelioma, cancer is found in the lining of the chest wall and may also be found in the lining of the lung, the lining of the diaphragm, or the lining of the sac that covers the heart on the same side of the chest.

Advanced malignant mesothelioma includes stage II, stage III, and stage IV.

In stage II, cancer is found in the lining of the chest wall and the lymph nodes on the same side of the chest. Cancer may also be found in the lining of the lung, the lining of the diaphragm, or the lining of the sac that covers the heart on the same side of the chest.
In stage III, cancer has spread to any of the following areas:
- The chest wall.
- The mediastinum.
- The heart.
- Beyond the diaphragm.
- The peritoneum.
Cancer may have also spread to lymph nodes on the other side of the chest or outside the chest.
In stage IV, cancer has spread to distant organs or tissues.

Treatment Option Overview

There are different types of treatment for patients with malignant mesothelioma.

Different types of treatments are available for patients with malignant mesothelioma. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. Before starting treatment, patients may want to think about taking part in a clinical trial. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.

Three types of standard treatment are used:

Surgery

The following surgical treatments may be used for malignant mesothelioma:

Wide local excision: Surgery to remove the cancer and some of the healthy tissue around it.
Pleurectomy and decortication: Surgery to remove part of the covering of the lungs and lining of the chest and part of the outside surface of the lungs.
Extrapleural pneumonectomy: Surgery to remove one whole lung and part of the lining of the chest, the diaphragm, and the lining of the sac around the heart.
Pleurodesis: A surgical procedure that uses chemicals or drugs to make a scar in the space between the layers of the pleura. Fluid is first drained from the space using a catheter or chest tube and the chemical or drug is put into the space. The scarring stops the build-up of fluid in the pleural cavity.

Even if the doctor removes all the cancer that can be seen at the time of the surgery, some patients may be given chemotherapy or radiation therapy after surgery to kill any cancer cells that are left. Treatment given after surgery, to increase the chances of a cure, is called adjuvant therapy.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). Combination chemotherapy is the use of more than one anticancer drug. The way the chemotherapy is given depends on the type and stage of the cancer being treated.

New types of treatment that are being tested in clinical trials include the following:

Biologic therapy

Biologic therapy is a treatment that uses the patient’s immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body’s natural defenses against cancer. This type of cancer treatment is also called biotherapy or immunotherapy.

Localized Malignant Mesothelioma (Stage I)

If the malignant mesothelioma is in one part of the chest lining, treatment will probably be surgery to remove the part of the chest lining with cancer and some of the tissue around it.

If localized malignant mesothelioma is found in more than one place in the chest, treatment may be one of the following:

Pleurectomy and decortication, with or without radiation therapy, as palliative therapy to relieve symptoms and improve the quality of life.
Extrapleural pneumonectomy.
Radiation therapy as palliative therapy to relieve symptoms and improve the quality of life.
A clinical trial of anticancer drugs placed directly into the chest after surgery to remove the tumor.
A clinical trial of combinations of surgery, radiation therapy, and chemotherapy.
A clinical trial of a new treatment.

Advanced Malignant Mesothelioma (Stage II, Stage III, and Stage IV)

Treatment of advanced malignant mesothelioma may include the following:

Surgery to drain fluid that has collected in the chest, to reduce discomfort. Pleurodesis may be done to stop more fluid from collecting in the chest.
Pleurectomy and decortication, as palliative therapy to relieve symptoms and improve the quality of life.
Radiation therapy as palliative therapy to relieve pain.
Chemotherapy with one anticancer drug.
A clinical trial of combination chemotherapy.
A clinical trial of combinations of surgery, radiation therapy, and chemotherapy.
A clinical trial of chemotherapy placed directly into the chest cavity or abdominal cavity to shrink the tumors and keep fluid from building up.

Recurrent Malignant Mesothelioma

Recurrent malignant mesothelioma is cancer that has recurred (come back) after it has been treated. The cancer may come back in the chest or abdomen or in other parts of the body.

Treatment of recurrent malignant mesothelioma may include the following:

A clinical trial of biologic therapy.
A clinical trial of chemotherapy.
A clinical trial of surgery.

Source: National Cancer Institute