Germ cell tumours of the brain

Germ cells are the reproductive cells in an unborn baby (fetus). Sometimes these cells travel from the reproductive organs (ovaries and testicles) to other parts of the body, where they can later become cancerous.

Germ cell tumours of the brain start from germ cells that have travelled to the brain. They occur mostly in the area above the pituitary gland or in the pineal region of the brain.

There are 3 types of germ cell tumours that develop in the brain:

• Germinomas are the most common type.
• Non-germinomatous germ cell tumours are less common. They are sometimes called mixed malignant germ cell tumours or secreting tumours because they can release substances (tumour markers) such as alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG).
• Teratomas are usually slow-growing or benign tumours, but they can become cancerous.

Germinomas and teratomas have a better prognosis than non-germinomatous germ cell tumours.

Treatments for germ cell tumours of the brain depend on the type of germ cell tumour. Surgery is often used to do a biopsy for diagnosis. But most germ cell tumours are treated with radiation therapy or a combination of radiation therapy and chemotherapy instead of surgery. This is because germ cell tumours are often hard to reach with surgery.

Germinomas are very sensitive to chemotherapy and radiation therapy. They may be treated with:

• chemotherapy followed by radiation therapy to the tumour
• whole-ventricle radiation therapy
• radiation therapy to the brain and spine (called craniospinal radiation)

Non-germinomatous germ cell tumours are sensitive to chemotherapy and radiation. They may be treated with:

• chemotherapy followed by radiation therapy to the tumour
• surgery if they don't respond to chemotherapy

Teratomas are treated with surgery to remove as much of the tumour as possible.

Recurrent germ cell tumours have come back after treatment. They are treated with:

• chemotherapy followed by radiation therapy
• high-dose chemotherapy with stem cell transplant, with or without additional radiation therapy

Radiation therapy uses high-energy rays or particles to destroy cancer cells. It is commonly used to treat germ cell tumours. Stereotactic radiosurgery is often used.

In children younger than 3 years of age, radiation is delayed (if possible) to avoid the long-term effects of radiation on developing brain cells. In these cases, chemotherapy will be given until the child reaches the age of 3. The type of radiation used is craniospinal radiation or whole-ventricle radiation with a boost to the primary tumour.

Find out more about radiation therapy for childhood brain and spinal cord tumours.

Chemotherapy uses drugs to destroy cancer cells. It is often combined with radiation therapy to treat germ cell tumours of the brain. This improves survival rates and allows doctors to give a lower dose of radiation. Chemotherapy could also be used to delay giving radiation therapy to children younger than 3 years of age.

Chemotherapy drugs that may be used include:

• cyclophosphamide
• ifosfamide (Ifex)
• etoposide (Vepesid)
• cisplatin
• carboplatin

Find out more about chemotherapy for childhood brain and spinal cord tumours.

Surgery is used to treat teratomas. It is not usually used to treat any other types of germ cell tumours of the brain, but it may be given if non-germinomatous germ cell tumours don’t respond to chemotherapy. Surgery is sometimes used to treat recurrent germ cell tumours.

Find out more about surgery for childhood brain and spinal cord tumours.

A stem cell transplant replaces stem cells. High-dose chemotherapy followed by a stem cell transplant (rescue) may be used to treat germ cell tumours of the brain that come back after treatment.

Find out more about stem cell transplant for childhood brain and spinal cord tumours.

Children with cancer may be treated in a clinical trial. Clinical trials look at new ways to prevent, find and treat cancer. Find out more about clinical trials.