India carries the biggest burden of Retinoblastoma globally, with an estimated 1500 new cases annually, which account for almost 20% of total Retinoblastoma population. Regular screening of the children at risk at is must for early identification and management.
Why should children be screened for Retinoblastoma?
It is a cancer and delayed identification and initiation of treatment causes loss of eyesight, eye or even death. if the disease is identified in early stage, it can be cure and sight as well as life of child can be saved. At-risk children should be screened very early in life by regular eye examinations so as to diagnose the cancer in its initial stages. It has been scientifically proven that early identification of the disease is associated with less advanced disease and better outcome in terms of saving vision and the eye.
Does every new born child needs to be screened for Retinoblastoma?
Who should be screened for Retinoblastoma?
All offspring, twins and siblings of Retinoblastoma patients should complete retinal examination for earliest identification of the disease. Other relatives need not be screened.
- At-risk children should undergo genetic testing
- The child’s age and risk level should determine the frequency of serial dilated fundus exams, which should be performed by a physician
- Newborns at high risk should be screened every 2 to 4 weeks during their first 2 months of life, whereas newborns with intermediate or low risk should be screened monthly.
- high risk means
- Bilateral Retinoblastoma diagnosed in any of the parents.
- intermediate risk means
- siblings of a patient diagnosed with bilateral Retinoblastoma
- children of a person whose one of the siblings has Bilateral Retinoblastoma
- children of a patient of Unilateral Retinoblastoma
- low risk means
- siblings of a patient diagnosed with Unilateral Retinoblastoma
- children of a person whose one of the siblings has Unilateral Retinoblastoma
- children of a person whose one of the siblings had a children with Bilateral Retinoblastoma
- Necessary exam frequency declines as the child ages and may be discontinued at age 7 for children without an RB1 mutation
- Children who carry an RB1 mutation should be screened indefinitely, every 1 to 2 years.
How is screening for Retinoblastoma done?
Complete eye examination is done by a trained ophthalmologist / eye surgeon with or without anaesthesia.
credit: National Eye Institute, NIH
Genetic testing of Retinoblastoma.
The test which can predict the occurrence of retinoblastoma in future, can help to save the vision of the patient and avoid unnecessary (and invasive) eye examinations for first person who develop disease (proband) in a facility and their close relatives. The disease exhibits a hereditary and a non-hereditary occurrence. One third of all children which have retinoblastoma had a heritable tendency to develop tumors. The mutation in retinoblastoma gene RB1 predisposes the retinal cells to undergo to malignant transformation, resulting in the disease occurrence. A child born to a parent with mutation in retinoblastoma gene RB1 has a 45% chance of developing retinoblastoma. These patients, multiple tumors and often in both the eyes. 15% of the patients, who have tumor in one eye, are also heritable. Siblings (brother and sister of patients with bilateral or unilateral retinoblastoma have a risk of 3% and 0.5%, respectively, to have retinoblastoma.
Genetic testing services of Retinoblastoma, available in India.
There are many hospitals which are offering the genetic testing for Retinoblastoma. At Shankar netralaya, this test cost around 12000 INR for a family of four (parents and two children). There are few private labs, which are also offering at price of about 30,000 INR per person. Genetic screening cost one sixth of the cost of clinical testing to rule out Retinoblastoma in a person.