Childhood Cancers: Retinoblastoma

Definition

A retinoblastoma is a cancer of the retina, the thin nerve tissue that lines the back of the eye that senses light and forms images. Although retinoblastoma may occur at any age, it most often occurs in younger children, usually before the age of 5 years. The tumour may be in one eye only or in both eyes. Most retinoblastomas occurring in only one eye is not hereditary and is more often found in older children. When the disease occurs in both eyes, it is always hereditary. Retinoblastoma is usually confined to the eye and does not spread to nearby tissue or other parts of the body. Retinoblastomas represent about 2 % of childhood cancers. A combined total of about 30 - 40 % of children with retinoblastoma have the gene for retinoblastoma, which they can pass on to their children.

Symptoms and Diagnosis

Symptoms of a retinoblastoma can include a white pupil or strabismus . However, other causes of a white pupil or strabismus are far more common. Retinoblastomas tend to produce few other symptoms. If a retinoblastoma is suspected the child is often examined under general anaesthesia and often a sample of cerebrospinal fluid and bone marrow is examined for cancer cells, as the retinoblastoma can spread to the brain and bone marrow. A CAT (computed tomography) scan may also be taken.

Treatment

Retinoblastomas that are confined to the eye are cured more than 90% of the time. The main treatment options include:

• Enucleation . When the cancer affects only one eye, the entire eyeball is removed, along with part of the optic nerve in surgery termed enucleation. If both eyes are effected, special microsurgical techniques are used to remove or destroy the tumour, so that both eyes don't need to be removed. Otherwise, one eye may be removed and the other treated with one of the other techniques listed below.
• Radiation therapy . High-energy radiation from x-rays and other sources to kill cancer cells and shrink tumours.
• Cryotherapy . The use of extreme cold to destroy cancer cells.
• Photocoagulation . The use of laser light to destroy blood vessels that supply nutrients to the tumour.
• Thermotherapy . The use of heat to destroy cancer cells.
• Chemotherapy . Anticancer drugs may be used, especially where the cancer has spread.

The eyes are re-examined every 2 to 4 months and other family members are also regularly examined. Children with the hereditary type of retinoblastoma have a high risk of having the cancer recur (within 30 years from the time of diagnosis, as many as 70% of those with a hereditary retinoblastoma develop a second cancer).

The information in this page is presented in summarised form and has been taken from the following source(s):
1. Pediatric Cancers, University of Pennsylvania Cancer Center: http://cancer.med.upenn.edu/