ABOUT RETINOBLASTOMA

Retinoblastoma (RB) is a rare, fast growing eye cancer of early childhood (typically before 5 years of age). Tumours may affect one eye (unilateral) or both eyes (bilateral), and typically develop before 5 years of age.  Some children are born with tumours.

 

Rarely, children with the hereditary form of Rb develop a tumour in the brain, usually the pineal gland.  This is known as trilateral retinoblastoma. Retinoblastoma arises from immature cells of the retina, the light-sensitive layer of cells at the back of the eye, which converts light into nerve signals.

Small fragments of tumour may break off the main tumour and invade the vitreous, the jelly-like centre of the eye.  This is called vitreous seeding.

If retinoblastoma is not treated promptly, cancerous cells can spread outside the eye, travelling along the optic nerve to the brain, or through blood vessels to the bone marrow.

Incidence

Between 25-30 children are newly diagnosed each year in Canada, 300-350 in the USA, and 40-50 in the UK.  Countries with high birth rates, like India, diagnose more than 1500 children with retinoblastoma each year.

Symptoms

The most easily recognizable sign is an abnormal appearance of the pupil, which reflects light as a white reflex (leukocoria), like a cat's eye. This is usually only visible in low artificial lighting or in photographs where a flash has been used. Occasionally a squint or crossed eyes can be the first sign of retinoblastoma.

Treatment

Current treatments include laser, cryotherapy (freezing the tumour), systemic and localized chemotherapy, brachytherapy (radioactive plaque sewn directly onto the tumour), radiotherapy and enucleation (surgical removal of the eye).

Prognosis

With early diagnosis and appropriate treatment, nine out of ten children with retinoblastoma can be cured today, creating one of the highest cure rates, and best success stories of all childhood cancers. 

However, without early intervention, the cancer will quickly spread beyond the eye, traveling directly to the brain, or invading the bone marrow.  Untreated retinoblastoma is fatal.