Though Retinoblastoma is the most common type of eye cancer found in children, most parents are unaware of the existence of this life-threatening cancer of the retina which occurs at the back of the eye. Representing three percent of all childhood cancer and occurring equally in both boys and girls and independent of race, retinoblastoma normally affects only one eye in up to 70 percent of patients, but a significant 30 percent cases involve both eyes. There are approximately three million cases of the illness affecting children under the age of 14 every year, and this rate is higher in predominantly developing regions: India, Central America and Sub-Saharan Africa. It is significantly rarer in the developed world with approximately 300 cases in the United States and 40 cases in the United Kingdom occurring annually. “In Saudi Arabia, the incidence of children suffering from this illness is about one in every 17,000 live births, and we encounter about 30 to 40 cases annually,” remarked Dr. Adel Mohamed Abdul Wahab Khalil, an Ophthalmologist at the Soliman Fakeeh Hospital in Jeddah, in an interview with Saudi Gazette. “The age incidence is usually between birth to six years, but commonly before three years of age. This is because retinoblastoma is due to the malignant transformation of primitive retinal cells – which tend to disappear within the first few years of life.” More than 90 percent of afflicted children can be cured of retinoblastoma through early detection and treatment, preserving a child's vision. “Early detection is vital for providing the child with a good chance to survive, avoid eye excision and preserve a good level of vision,” added Dr. Khalil. Difficult choices Dr. Michael Dean, an Oncologist from the renowned Simmons Comprehensive Cancer Center in the United States writes that if the tumor is found in one eye, then it is normally safe to remove that eye without posing a risk to the other. In such cases, new prostheses are “remarkably good” and “children can lead a normal life with one eye.” However, when detected in both eyes, then the worst-affected one is normally removed and the other specialists attempt to save. Detection Retinoblastoma is normally found via routine eye examinations, but it can also show up as a white lesion in the eye or the lack of the ‘red eye' phenomenon in photographs, painful headaches and vision trouble. The tumor can either be confined to the eye, spread to the optic nerve or spread even further as well in the worst-case scenario. One useful way the tumor can be detected by parents is when using a flash to take pictures of a certain child, where an affected eye may look white in the photograph. Some children also look like they are squinting or if the tumor is particularly large the afflicted eye will look painfully red. “The most common symptoms are white opacity in the center of the pupil, squinting, pain in the eye, redness and eye enlargement caused but elevated intraocular pressure,” explained Dr. Adel. “If the tumor is confined to the retina for a long time, it will spread inside the eye, along the optic nerve, to the orbit, lymph nodes, lungs, brain and bones.” Types of tumor Retinoblastoma can occur in two forms: heritable and non-heritable. In the former, the tumor is often bilateral – occurring in both eyes, while in the latter it is normally found in just one eye. The heritable form of retinoblastoma accounts for about two in every five cases, and is caused by a genetic abnormality. This means that an abnormal gene allows the tumor to develop, and may either be inherited from a parent or occur for the first time at an early stage of development in the womb. People with this gene - known as the RB1 - also have an increased risk of developing other types of tumor later in life, according to Dr. Khalil. “In heritable retinoblastoma, the child carries a 40 percent risk if a parent has been affected with it. In this type, the disease may affect more than one child in the same family,” he said. “In non-heritable retinoblastoma, the tumor is unilateral and non-transmissible. The child of a non-heritable retinoblastoma parent has only 1% risk of getting it.” Treatment Treatment for this cancer typically requires the cooperation of an ophthalmic oncologist, pediatric oncologist, and radiation therapist. Investigations via eye ultrasound, CT scan, MRI and some genetic studies may be conducted by the consultant ophthalmologist. The genetic study involves testing a child's blood for the RB1 gene and results can take months to come back, so parents must be prepared to wait. The other investigations are fairly straightforward and completely painless. The kind of treatment used depends on the number, position and size of the tumor in the eye. The treatment initially seeks to get rid of the cancer and then to preserve vision. Depending on the treatment, some patients may lose partial vision. Dr. Khalil remarked that treatment methods included laser treatment, cry therapy, chemotherapy, radiotherapy and enucleating in very advanced cases. He advises parents to put their worry to rest by having periodic tests done on their child. “This disease is statistically rare but we need to consider the risks it poses nevertheless,” he said. “Routine check ups are mandatory for high-risk cases, particularly is there is a family history of the disease.”
