Retinoblastoma: Curable cancer in children
Worldwide, every May, the week after the second Sunday is celebrated as “World Retinoblastoma Awareness Week”. The entire week is dedicated to increasing awareness about Retinoblastoma. This year, “World Retinoblastoma Awareness Week” is observed from May 13 - 19, 2018.
Retinoblastoma, a rare kind of eye cancer, has started emerging rapidly over the years among the children in India. India must create awareness on the importance of early detection of the disease so that children enjoy better chances of eye and vision preservation. The incidence of the disease is1 in 18,000 live births. Worldwide, every year we witness about 8,000 to 10,000 new cases. Retinoblastoma is one of the rarer kinds of cancers prevalent today with the abnormality in the gene being congenital (present at birth) in some cases. In genetic cases, both eyes tend to be afflicted.
Retinoblastoma commonly affects children younger than 3 years old. It appears as a white reflex in the eye or squint, both of which can be easily detected by parents. The white reflex is very noticeable in photographs. If parents notice a white reflex or squint, an urgent eye examination is recommended to rule out retinoblastoma. If neglected, the tumor can grow beyond the eye and spread to the brain.
When the disease is detected early, it is curable. Life, eye, and vision can be salvaged with appropriate treatment. The chances of survival in children with retinoblastoma confined to the eye is >90% versus 70% when the tumor spreads beyond the eye. If the tumor spreads into the brain, the chances of survival are very poor. Various forms of treatment are available for retinoblastoma. When the tumor is small, it can be treated with simple eye laser or cryotherapy. If it is larger in size, systemic intravenous chemotherapy is needed. Generally, children tolerate systemic intravenous chemotherapy better than adults. They may have side-effects like weight loss, loss of appetite, hair loss and frequents infections while on chemotherapy but all these are temporary, and the child recovers very well after completion of chemotherapy.
There have been recent advances in chemotherapy, and it can be delivered directly into the eye via the intra-arterial route. Intra-arterial chemotherapy is a complex procedure and requires a qualified team of the ocular oncologist, radiation oncologist, medical oncologist, and interventional neurosurgeon. The drug is delivered through the artery in the thigh, a femoral artery that is used to gain access to the artery in the eye known as the Ophthalmic artery. The advantage of intra-arterial chemotherapy is minimal systemic circulation of the chemotherapy drug thus minimizing the systemic side-effects
Another new form of delivery of chemotherapy is a direct injection of chemotherapy drug into the eye via intra-vitreal approach. This form of treatment is useful in selective cases with tumor seeds in the vitreous. An experienced ocular oncologist should do intra-vitreal chemotherapy meticulously since an inappropriate technique can cause tumor dissemination outside the eye. This technique is not associated with systemic complications, but the child can have drug-related toxic changes in the retina.
Radiotherapy is rarely used in the treatment of retinoblastoma nowadays. Plaque radiotherapy is a method of focal radiation delivery, which is used in some cases that do not respond to chemotherapy. External beam radiotherapy is used in cases where the tumor has extended beyond the eye.
Removal of the eye or enucleation may still be needed in few cases where the tumor is advanced or does not respond to conservative management. This can be avoided if the tumor is detected early. Even if an eye is removed, the child can lead a good quality life with a customized ocular prosthesis, which may not provide a vision but can simulate a normal eye externally.
It is time to make detailed eye check-ups a part of mandatory paediatric examinations. Parents and physicians should be educated about symptoms which could otherwise be easily dismissed as an infection. There is a need for increased awareness about this life-threatening disease among parents.
The author Dr. Swathi Kaliki is an ocular oncologist and head - Operation Eyesight Universal Institute for Eye Cancer at L V Prasad Eye Institute, Hyderabad.