Chemotherapy for retinoblastoma

Chemotherapy uses anticancer (cytotoxic) drugs to destroy cancer cells. It is usually used to treat retinoblastoma. The healthcare team will consider your child’s needs to plan the drugs, doses and schedules of chemotherapy. Your child may also receive other treatments.

Chemotherapy is given for different reasons. Your child may have chemotherapy to:

• destroy cancer cells in the body
• shrink a tumour before other treatments (called neoadjuvant chemotherapy)
• destroy cancer cells left behind after surgery and reduce the risk that the cancer will come back (recur) (called adjuvant chemotherapy)
• prepare for a stem cell transplant to treat advanced retinoblastoma that has spread outside the eye (extraocular retinoblastoma) or come back outside the eye
• relieve pain or control the symptoms of advanced retinoblastoma (called palliative chemotherapy)

Chemotherapy is usually a systemic therapy. This means that the drugs travel through the blood to reach and destroy cancer cells all over the body, including those that may have broken away from the primary tumour in the eye. Systemic chemotherapy is often used to shrink a tumour before other treatments such as cryotherapy, thermotherapy, laser surgery or radiation therapy.

Chemotherapy may also be a regional therapy, which means that it is given to a specific area of the body. The following kinds of regional chemotherapy may be used to treat retinoblastoma. Children may be given a general anesthetic or sedation depending on the procedure.

Periocular (subtenon) chemotherapy is chemotherapy that is injected into the tissues around the eye. Carboplatin is the most common chemotherapy drug used in periocular chemotherapy.

Intra-arterial chemotherapy is chemotherapy that is injected into the main artery that carries blood to the eye (called the ophthalmic artery). A thin catheter is inserted into a large artery on the inner thigh and slid up to the ophthalmic artery. Chemotherapy is then given through the catheter into the ophthalmic artery. Chemotherapy drugs commonly used for intra-arterial chemotherapy are carboplatin and topotecan.

Intravitreal chemotherapy is chemotherapy that is injected into the jelly-like substance in the eye (called the vitreous humour).

Intrathecal chemotherapy is chemotherapy given to the brain and spinal cord (called the central nervous system, or CNS). Intrathecal chemotherapy is given through a lumbar puncture into the space containing the cerebrospinal fluid (CSF). Intrathecal chemotherapy is sometimes used to treat retinoblastoma that has spread to the brain.

The most common chemotherapy drugs used to treat retinoblastoma are:

• carboplatin
• cisplatin
• vincristine
• etoposide (Vepesid)
• cyclophosphamide (Procytox)
• doxorubicin
• topotecan

The most common chemotherapy drug combinations used to treat retinoblastoma are:

• carboplatin, vincristine and etoposide
• carboplatin, vincristine, etoposide and cyclosporine (Neoral)
• vincristine, doxorubicin and cyclophosphamide
• vincristine and cyclophosphamide
• doxorubicin and cyclophosphamide
• topotecan and cytarabine (Cytosar)

Side effects can happen with any type of treatment for retinoblastoma, but every child’s experience is different. Some children have many side effects. Other children have few or none at all.

Chemotherapy may cause side effects because it can damage healthy cells as it kills cancer cells. If your child develops side effects, they can happen any time during, immediately after or a few days or weeks after chemotherapy. Sometimes late side effects develop months or years after chemotherapy. Most side effects go away on their own or can be treated, but some side effects may last a long time or become permanent.

It is hard to say exactly which side effects a child will have, how long they will last and when the child will recover. A child’s body seems to handle chemotherapy better than an adult’s body. Children usually have less severe side effects and will often recover from them faster than adults.

Side effects of chemotherapy will depend mainly on the type of drug, the dose, how it’s given and your child’s overall health. There are fewer side effects from regional chemotherapy than from systemic chemotherapy because regional chemotherapy usually does not affect the entire body. Some common side effects of chemotherapy drugs used for retinoblastoma are:

• hair loss
• sore mouth
• loss of appetite
• nausea and vomiting
• bone marrow suppression ( low blood cell counts)
• diarrhea
• constipation
• fatigue
• increased risk of infections
• bleeding easily ( low platelet count)

Other side effects can develop months or years after treatment for retinoblastoma. Find out more about late effects of treatments for retinoblastoma.

Tell your child’s healthcare team if your child has these side effects or others you think might be from chemotherapy. The sooner you tell them of any problems, the sooner they can suggest ways to help your child deal with them.

Details on specific drugs change regularly. Find out more about sources of drug information and where to get details on specific drugs.

Find out more about chemotherapy and side effects of chemotherapy. To make the decisions that are right for your child, ask the healthcare team questions about chemotherapy.