Mesothelioma is a disease in which malignant (cancer) cells form in the thin layer of tissue that covers organs in the chest or abdomen.

Malignant mesothelioma is a disease in which malignant (cancer) cells are found in one or more of the following:

• Pleura: A thin layer of tissue that lines the chest cavity and covers the lungs.
• Peritoneum: A thin layer of tissue that lines the abdomen and covers most of the organs in the abdomen.
• Pericardium: A thin layer of tissue that surrounds the heart.

The tumors often spread over the surface of organs without spreading into the organ. They may spread to nearby lymph nodes or in other parts of the body. Malignant mesothelioma may also form in the testicles, but this is rare.

Certain factors affect prognosis (chance of recovery).

Prognosis depends on whether the cancer:

• has spread throughout the thin layer of tissue or into organs.
• has just been diagnosed or has recurred (come back).

Treatment with radiation therapy increases the risk of childhood mesothelioma.

Anything that increases your chance of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn't mean that you will not get cancer. Talk with your child's doctor if you think your child may be at risk.

Treatment for an earlier cancer, especially radiation therapy, increases the risk of mesothelioma in children.

In adults, mesothelioma is strongly linked to being exposed to asbestos, which has been used in the building and textile industries. In children, there is little information about the risk of developing mesothelioma after being exposed to asbestos.

Signs and symptoms of mesothelioma include trouble breathing and pain in the chest or abdomen.

In children, these and other signs and symptoms may be caused by mesothelioma or by other conditions.

Check with your child's doctor if your child has any of the following:

• Trouble breathing.
• Cough for no known reason.
• Pain under the rib cage or pain in the chest and abdomen.
• Weight loss for no known reason.
• Feeling very tired.

Tests that examine the chest, abdomen, and heart are used to diagnose mesothelioma.

The following tests and procedures may be used:

• Physical exam and health 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 and 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.
• CT scan (CAT scan): A procedure that makes a series of detailed pictures of areas inside the body, 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.
• PET scan (positron emission tomography scan): A procedure to find malignant tumor cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do.

• MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).
• Pulmonary function test (PFT): A test to see how well the lungs are working. It measures how much air the lungs can hold and how quickly air moves into and out of the lungs. It also measures how much oxygen is used and how much carbon dioxide is given off during breathing. This is also called a lung function test.
• Fine-needle aspiration (FNA) biopsy: The removal of tissue or fluid using a thin needle. A pathologist views the tissue or fluid under a microscope to look for cancer cells.
• Thoracoscopy: A surgical procedure to look at the organs inside the chest to check for abnormal areas. An incision (cut) is made between two ribs and a thoracoscope is inserted into the chest. A thoracoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue or lymph node samples, which are checked under a microscope for signs of cancer. In some cases, this procedure is used to remove part of the esophagus or lung.
• Bronchoscopy: A procedure to look inside the trachea and large airways in the lung for abnormal areas. A bronchoscope is inserted through the nose or mouth into the trachea and lungs. A bronchoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue samples, which are checked under a microscope for signs of cancer.
• Laparoscopy: A surgical procedure to look at the organs inside the abdomen to check for abnormal areas. Small incisions (cuts) are made in the wall of the abdomen and a laparoscope (thin, lighted tube) is inserted into one of the incisions. Other instruments may be inserted through the same or other incisions to perform procedures such as removing organs or taking tissue samples to be checked under a microscope for signs of cancer.
• 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.

The process used to find out if cancer has spread from where it first began is called staging. In childhood mesothelioma, cancer may spread to nearby or distant lymph nodes. There is no standard staging system for childhood mesothelioma. The results of tests and procedures done to diagnose mesothelioma are used to help make decisions about treatment.

Sometimes childhood mesothelioma recurs (comes back) after it has been treated.

Treatment Option Overview

There are different types of treatment for children with mesothelioma.

Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. 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.

Because cancer in children is rare, taking part in a clinical trial should be considered. Some clinical trials are open only to patients who have not started treatment.

Children with mesothelioma should have their treatment planned by a team of doctors who are experts in treating childhood cancer.

Treatment will be overseen by a pediatric oncologist, a doctor who specializes in treating children with cancer. The pediatric oncologist works with other pediatric health professionals who are experts in treating children with cancer and who specialize in certain areas of medicine. This may include the following specialists and others:

• Pediatrician.
• Pediatric surgeon.
• Radiation oncologist.
• Pathologist.
• Pediatric nurse specialist.
• Social worker.
• Rehabilitation specialist.
• Psychologist.
• Child-life specialist.

Three types of treatment are used:

Surgery

Surgery to remove the tumor may be used to treat childhood mesothelioma.

Chemotherapy

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them 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).

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. External radiation therapy uses a machine outside the body to send radiation toward the area of the body with cancer.

Targeted therapy

Targeted therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells. Targeted therapies usually cause less harm to normal cells than chemotherapy or radiation therapy do.

Targeted therapy is being studied for the treatment of childhood mesothelioma that has recurred (come back).

Immunotherapy

Immunotherapy 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 cancer treatment is a type of biologic therapy.

Treatment for childhood mesothelioma may cause side effects.

Side effects from cancer treatment that begin after treatment and continue for months or years are called late effects. Late effects of cancer treatment may include:

• Physical problems.
• Changes in mood, feelings, thinking, learning, or memory.
• Second cancers (new types of cancer) or other conditions.

Some late effects may be treated or controlled. It is important to talk with your child's doctors about the possible late effects caused by some treatments.

Patients may want to think about taking part in a clinical trial.

For some patients, taking part in a clinical trial may be the best treatment choice. Clinical trials are part of the cancer research process. Clinical trials are done to find out if new cancer treatments are safe and effective or better than the standard treatment.

Many of today's standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.

Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.

Patients can enter clinical trials before, during, or after starting their cancer treatment.

Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment.

Follow-up tests may be needed.

Some of the tests that were done to diagnose the cancer or to find out the stage of the cancer may be repeated. Some tests will be repeated in order to see how well the treatment is working. Decisions about whether to continue, change, or stop treatment may be based on the results of these tests.

Some of the tests will continue to be done from time to time after treatment has ended. The results of these tests can show if your child's condition has changed or if the cancer has recurred (come back). These tests are sometimes called follow-up tests or check-ups.

Treatment of Childhood Mesothelioma

Treatment of newly diagnosed mesothelioma in children may include the following:

• Surgery to remove the part of the chest lining with cancer and some of the healthy tissue around it.
• Chemotherapy.
• Radiation therapy, as palliative therapy, to relieve pain and improve quality of life.
• Clinical trials of newer drugs and immunotherapy.

Treatment of Recurrent Childhood Mesothelioma

Treatment of recurrent mesothelioma in children may include the following:

• A clinical trial that checks a sample of the patient's tumor for certain gene changes. The type of targeted therapy that will be given to the patient depends on the type of gene change.