Retinoblastoma

Retinoblastoma
Rb tumours taken with a retinoscan before and during chemotherapy

Retinoblastoma (Rb) is a rapidly developing cancer which develops in the cells of the retina, the light sensitive cells of the eye. In the developed world, Rb has one of the best cure rates of all childhood cancers (95-98%), with more than nine out of every ten sufferers surviving into adulthood. Retinoblastoma is a very treatable cancer.

There are two forms of the disease; a genetic heritable form and a non-genetic non-inheritable form. Approximately 55% of children with Rb have the non-genetic form. If there is no history of the disease within the family, the disease is labelled "sporadic", but this does not necessarily indicate that it is the non-genetic form. In about two thirds of cases, only one eye is affected (unilateral retinoblastoma); in the other third, tumours develop in both eyes (bilateral retinoblastoma). The number and size of tumours on each eye may vary. The position, size and quantity of tumours are considered when choosing the type of treatment for the disease.

Symptoms

The most common and obvious symptom is an abnormal appearance of the pupil. In a healthy eye, the pupil may appear red when captured on a photograph where a flash has been used (Red Eye), whereas on an affected eye, the pupil may appear white or yellow (leukocoria). The yellowy appearance may also be visible in low artificial light and will resemble a cat’s eye.

Other less common symptoms are: deterioration of vision, a red and irritated eye, faltering growth or delayed development. Some children with retinoblastoma can develop a squint (strabismus).

Should you notice any of these symptoms or have cause for concern, you should visit your GP or paediatrician. If a white eye reflection has been spotted on a photograph, take the photograph with you when you see your GP/Paediatrician. Depending on the position of the tumours, they may be visible using an ophthalmoscope to look through the pupil. A positive diagnosis is usually made only with an examination under anaesthetic (EUA).

Note: A white eye reflection is not always a positive indication of Rb and can be caused by light being reflected badly or by other conditions such as Coats's Disease.

Frequency of retinoblastoma

Retinoblastoma is rare and affects approximately 1 in 20,000 births worldwide. In the UK around 40 to 50 new cases are diagnosed each year. Most children are diagnosed before the age of five years old. In the UK bilateral cases usually present within the first year with the average age at diagnosis being 9 months. Diagnosis of unilateral cases peaks between 24 and 30 months.

Cause of retinoblastoma

In children with the heritable genetic form of retinoblastoma there is something wrong with part of the genetic material on chromosome 13, called the RB1 gene. The genetic codes found in chromosomes control the way in which cells grow and develop within the body. If a portion of the code is missing or altered (mutation) a cancer may develop. The defective RB1 gene can be inherited from either parent, however in some children, the mutation occurs in the early stages of foetal development. It is not known what causes the gene abnormality; it is most likely to be a random mistake during the copy process which occurs when a cell divides.

Treatment

Treatment of retinoblastoma varies from country to country. The first priority is to preserve the life of the child, then to preserve the vision and thirdly to minimize any complications or side effects of the treatment. The exact course of treatment will depend on the individual case and will be decided by the Ophthalmologist in discussion with the Paediatric Oncologist. Options for treatment include: chemotherapy, cryotherapy, radioactive plaques, laser therapy, external beam radiotherapy and surgery. Any combinations of these treatments may be adopted.

Support

Help for survivors of retinoblastoma and the families of children with the disease is available in many countries. The following is a list of some charities and organizations that are there to help:

Retinoblastoma International (RBI)

Country	Organization	Description
United Kingdom	The Childhood Eye Cancer Trust (CHECT)	A charity for families and individuals affected by retinoblastoma. They offer support and information, fund research and raise awareness of this rare cancer.
Global – focus on developing countries	Daisy’s Eye Cancer Fund	'A global response to childhood retinoblastoma' Daisy's Eye Cancer Fund is a registered charity in England, and a special fund within SickKids Foundation (the Charitable Foundation of Toronto's Hospital for Sick Children), Canada. Daisy’s Eye Cancer Fund is the world's only retinoblastoma charity taking a global approach to the needs of children affected by this cancer. With a particular focus on developing countries, they are committed to improving care for all children diagnosed with retinoblastoma. Their goal is to encourage the development of sustainable, locally managed diagnosis and treatment programs in under-served regions of the world so that, one day soon, no child will face death from an entirely treatable cancer due to lack of awareness or resources. Daisy’s Fund is named in honour of a brave school girl from Devon, England and driven by the memory of another Valliant little girl from Africa.
France	Retinostop	Retinostop is a charity which supports families, facilitate parents meetings, support research and help equip treatment centres. They promote early diagnosis amongst health professionals and government administrations. They have produced a booklet for children about a girl called Mirabelle and her cat Tino who both need artificial eyes made for them.
United States	Eye Cancer Network	Ocular oncology; diseases, treatment and research. 'An educational website about the diagnosis and treatment of eye tumours. Find eye tumour doctors, eye tumour information and support (for eye tumour patients and their families)' An American website, supported by The Eye Care Foundation, that is concerned with all forms of eye cancer but has a link to Retinoblastoma on the home page. The information is simple but informative; it is interesting to look at Retinoblastoma alongside other forms of eye cancer.
Retinoblastoma International (RBI)	'Fighting children's eye cancer' RBI is a non profit organisation founded in LA in 1998 since then RBI has been committed to supporting education, clinical care, research, early diagnosis and awareness. In the year 2000, RBI helped pass California Assembly Bill 2185, AB2185 which promotes early and regular eye examinations for infants, to detect the presence of tumours and numerous other eye problems.
United States	Retinoblastoma.com	Written by Dr David H. Abramsom now Chief of Ophthalmic Oncology at memorial Sloan-Kettering Cancer Center (MSKCC) in New York City. He runs the largest programme for children with Retinoblastoma in the US. Several years ago Dr Abramsom put together this website describing Retinoblastoma, his programme and some of the educational resources available to individuals with Retinoblastoma.
Canada	The Canadian Retinoblastoma Society (CRBS)	CRBS is a charitable organisation which supports Canadians affected by retinoblastoma. It also works to raise awareness through education and also provides an advocacy service.

Additional images

Retinoblastoma rosette

Retina scan before and during chemotherapy treatment