Childhood midline tract carcinoma is a disease in which malignant (cancer) cells form in the respiratory tract or other places along the middle of the body.

The respiratory tract is made up of the nose, throat, larynx, trachea, bronchi, and lungs. Midline tract carcinoma may also form in other places along the middle of the body, such as the thymus, the area between the lungs, the pancreas, liver, and bladder.

Midline tract carcinoma is sometimes caused by a change in the NUT gene.

Midline tract carcinoma is caused by a change in a chromosome. Every cell in the body contains DNA (genetic material stored inside chromosomes) that controls how the cell looks and acts. Midline tract carcinoma may form when part of the DNA from chromosome 15 (called the NUT gene) joins with the DNA from another chromosome.

The signs and symptoms of midline tract carcinoma are not the same in every child.

The signs and symptoms of midline tract carcinoma depend on where the cancer formed in the body.

Midline tract carcinoma grows and spreads quickly.

Midline tract carcinoma with NUT gene changes is an aggressive cancer that cannot be cured.

Tests that examine the body are used to help diagnose midline tract carcinoma.

The tests used to diagnose midline tract carcinoma depend on where the cancer formed in the body and may include the following:

• 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 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.
• MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas of the body, such as the head and neck. This procedure is also called nuclear magnetic resonance imaging (NMRI).
• 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.

• Biopsy: The removal of cells so they can be viewed under a microscope by a pathologist to check for signs of cancer.

  The following tests may be done on the sample of cells that was removed:

  • Immunohistochemistry: A laboratory test that uses antibodies to check for certain antigens (markers) in a sample of a patient’s tissue. The antibodies are usually linked to an enzyme or a fluorescent dye. After the antibodies bind to a specific antigen in the tissue sample, the enzyme or dye is activated, and the antigen can then be seen under a microscope. This type of test is used to help diagnose cancer and to help tell one type of cancer from another type of cancer.
  • Cytogenetic analysis: A laboratory test in which the chromosomes of cells in a sample of bone marrow, blood, tumor, or other tissue are counted and checked for any changes, such as broken, missing, rearranged, or extra chromosomes. Changes in certain chromosomes may be a sign of cancer. Cytogenetic analysis is used to help diagnose cancer, plan treatment, or find out how well treatment is working. Other tests, such as fluorescence in situ hybridization (FISH), may also be done to look for certain changes in the chromosomes.

The process used to find out if cancer has spread from where it first began to nearby areas or to other parts of the body is called staging. There is no standard staging system for childhood midline tract carcinoma. The results of the tests and procedures done to diagnose midline tract carcinoma are used to help make decisions about treatment.

Childhood midline tract carcinoma may spread to the lymph nodes, the lining around the lung, bone marrow, or bone.

There are different types of treatment for children with midline tract carcinoma.

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 midline tract carcinoma 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 is one of the main treatments used for childhood midline tract carcinoma.

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.

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).

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. New targeted therapy drugs that stop cancer cells from growing are being studied to treat midline tract carcinoma.

Treatment for childhood midline tract carcinoma may cause side effects.

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 Midline Tract Carcinoma

There is no standard treatment for newly diagnosed midline tract carcinoma with NUT gene changes. Treatment may include the following:

• Surgery to remove the tumor.
• External radiation therapy.
• Chemotherapy.

Treatment of Recurrent Childhood Midline Tract Carcinoma

Treatment of recurrent midline tract carcinoma with NUT gene changes 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.
• A clinical trial that is testing a new group of drugs called BET bromodomain inhibitors in younger patients.