Chemotherapy for retinoblastoma
Chemotherapy (drug treatment) is usually used in the first stage of treatment for patients with bilateral retinoblastoma and can be used for both small and large tumours.
It is also sometimes used for unilateral retinoblastoma, but only in situations where there is a good chance of preserving useful vision in the affected eye. Between four and six cycles of chemotherapy, at 3-4 weekly intervals, are usually given and local therapy (laser, cryotherapy or radioactive plaque) can be introduced once the tumour has shrunk.
Chemotherapy may also be required after an eye has been removed by surgery (enucleation), if there are signs that the tumour had involved the nerve, the deeper layers of the eye or the front chamber of the eye. In this situation usually only four cycles will be needed.
Children with a known family history of retinoblastoma receive regular screening at one of the retinoblastoma centres from birth and therefore tend to be diagnosed at a younger age. If tumours are found, they are more likely to be relatively small. For such children, a combination of local therapy (cryotherapy or laser) with or without the addition of chemotherapy is the usual treatment.
The first course of chemotherapy is referred to as ‘first line’ chemotherapy.
When chemotherapy is recommended, the child will be under the care of a paediatric oncologist (children’s cancer doctor), who specialises in the drug treatment of cancer in children. Chemotherapy is given via an intravenous line (known as a central line), and this will stay in for the duration of the whole course of treatment. The nursing staff on the children’s cancer ward will teach the parents how to look after the central line.
Chemotherapy is usually given at the nearest children’s cancer centre and arrangements will be made for the child to be seen locally in between cycles of chemotherapy or if the child is unwell.
Possible side-effects of chemotherapy:
- Nausea and vomiting – this can be treated with anti-sickness drugs,
- Increased susceptibility to infection – this may require treatment in hospital with antibiotics,
- Tendency to bruise easily
- Anaemia
- Thinning or loss of hair- this will regrow after completion of the treatment.
Side effects from chemotherapy are reassuringly low and most patients can expect very few late effects. The drugs used to treat retinoblastoma (carboplatin, etoposide and vincristine) are very well tolerated. However, a small number may develop complications specific to the drug, and these tend to occur with greater frequency the higher the dose received. Occasionally, if first line drugs have not been successful or if treatment was given many years ago, additional or alternative chemotherapy drugs will be used to treat retinoblastoma. The side effects of these will be discussed with the patient on an individual basis.
Complications from chemotherapy can include:
- Hearing problems:
These are uncommon but may occur with certain drugs and after radiotherapy to the head, in the region of the ear. Carboplatin very infrequently may cause hearing impairment (i.e. partial deafness) and can be detected by sensitive hearing tests. Hearing problems due to carboplatin do not get worse after treatment has finished but once hearing problems are present, they usually remain. - Kidney problems:
Kidney problems can occur after carboplatin, but they are rare and not usually severe. The main job of the kidney is to get rid of waste products from the blood stream into the urine. It is also involved in controlling blood pressure. Carboplatin can reduce the efficiency with which the kidneys ‘clean’ the blood, and may make the kidneys ‘leaky’. This means that the body loses too much of certain substances, e.g. some salts such as phosphate. These substances may need to be replaced by medicines or tablets taken regularly to supplement the losses from the kidneys. Kidney damage is always evident at or within a few months of finishing treatment.
There is no evidence that shows fertility is impaired by the drugs used in the first line chemotherapy treatment of retinoblastoma.
There are also localised forms of chemotherapy that may be used to treat your child’s retinoblastoma, such as intra-arterial chemotherapy (IAC), and intravitreal chemotherapy (IVC).
If your child needs chemotherapy, you may find our advice leaflet from other parents of use.
If you have any queries or concerns about your child’s treatment, contact your Retinoblastoma Team at either to Birmingham Women’s & Children’s Hospital or the Royal London Hospital.