1. What is Retinoblastoma?

Retinoblastoma is a rare eye cancer that usually affects children under the age of five, although it can affect children at  any age. Retinoblastoma develops in the light-sensitive lining of the eye (called the retina). Treatment is very effective and most of the children with retinoblastoma can be cured.

There are two forms of retinoblastoma:

• A heritable form – It passes through families. Usually, it affects both eyes (bilateral) and sometimes only in one eye.

• A non-heritable form – this is not passed through the family. It affects only one eye (unilateral).

2. What are the causes of retinoblastoma?

In nearly all cases, retinoblastoma is caused by an abnormality in the retinoblastoma gene (RB1). In the heritable form of retinoblastoma, this abnormal gene is either inherited from a parent or forms during  early stage of development in the womb. Parents with retinoblastoma will not pass down this gene to all the children. Children born into families with a history of retinoblastoma can have blood testing to look for the abnormal gene. They are also usually checked (screened) regularly for signs of retinoblastoma after birth. Therefore treatment can be started early if a tumour is detected. 

In the non-heritable form of retinoblastoma, the abnormality in the RB1 gene occurs in the cells on the retina. The reason for this happening is unknown.

3. What are the signs and symptoms?

If there’s no family history of retinoblastoma, the first sign of the condition is often a white pupil which does not reflect light (leukocoria). This may be picked up when a picture of your child is taken using flash photography. The pupil of the affected eye may look white in the photograph. Some children may have a squint or, if the tumour is large, they may have a painful eye.

4. How is retinoblastoma diagnosed?

Tests involve  examination under an anaesthetic (EUA) where an eye specialist (ophthalmologist) examines your child’s eye while sleeping . It’s usually not necessary to take a sample of tissue for  biopsy. 

5. What does the stage of the cancer mean? How do you determine in case of retinoblastoma?

The  cancer stage describe its size and whether it has spread beyond its original site. Knowing the stage of the cancer helps doctors decide on the most appropriate treatment.

The tests carried out are called staging tests, which include, blood tests, CT, and MRI

Some tests that may be done are:

·   Ultrasound scans: This is a painless scan that uses sound waves to examine the eye and the surrounding area.

·   An MRI (magnetic resonance imaging) scan: This provides a detailed picture of the eye and the head.

·   A lumbar puncture: The doctor inserts a fine needle between the bones in the lower spine to remove a sample of the fluid from around the brain and the spinal cord (cerebrospinal fluid). The fluid is examined under a microscope to check whether there are any cancer cells present.

·   A bone marrow sample: This may be taken to check whether there are any cancer cells in the bone marrow (where our blood cells are made). The doctor inserts a needle into the hipbone and draws some of the bone marrow out with a syringe so that it can be checked for cancer cells.

·   A bone scan: This involves taking special x-rays to check for any signs of  spread to the bones.

·   A blood test. This may be taken for genetic testing for the Rb gene.

6. What are the treatments for Retinoblastoma?

This depends on the number, position and size of the tumors in the eye. The aim of treatment is firstly to get rid of the cancer and secondly to try to keep vision intact. . Some treatments may cause changes to the vision in the affected eye. Your child’s specialist will talk to you about the possible risks as well as the advantages of the treatment.

·  For smaller tumors,

Treatment is given to the eye itself (called local therapy), while your child is asleep and under anaesthesia. One of the following methods may be used:

Cryotherapy

This is used to freeze the tumors. More than one session may be necessary, in which case they are usually done at monthly intervals. 

Laser therapy

A laser is directed through  the pupil and used to heat the tumour. Your child may need a number of sessions of laser therapy (under general anaesthetic) at intervals of 3-4 weeks. 

Larger tumors

These can be treated in a number of ways, including:

Chemotherapy

This is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. It may be given before the local treatments mentioned above, to help shrink the tumour and increase the success of the treatment. Chemotherapy can also be used if the cancer has spread to other parts of the body, or if there’s a risk that it may spread.

Surgery

If the tumour is very large and vision in the eye is lost, your child will  likely  need an operation to remove the eye. The specialist will only do this if it is absolutely necessary. An artificial eye is then fitted.

Radiotherapy

Radiotherapy treats cancer by using high energy rays from a machine to destroy the cancer cells, while doing as little harm as possible to the normal cells. It can be given to the whole eye but does have some effect on the surrounding tissue. Radiotherapy for retinoblastoma is normally used only when other treatments have not worked well.

7. What are the follow-up care needed in case of retinoblastoma?

Most  children with retinoblastoma can be cured. Following treatment, the eye specialist will frequently examine your child’s eye under anaesthesia  to check if the retina is healthy, the cancer has not come back, and no new tumors have developed. Children with heritable retinoblastoma will be given genetic counselling when they are old enough to understand it.

Having the heritable form of retinoblastoma means an increased risk of developing other types of cancer later in life. Your child will be followed up closely into adulthood.