Retinoblastoma (Rb) is a rare form of cancer that rapidly develops from immature cells of the retina. It is a malignant Cancer of the eye, found exclusively in young children below 7 years of age. In 75% of cases, the tumor is found only in one eye, while the rest 25% cases report tumor in both eyes.
Retinoblastoma is usually confined to the eye but, if left untreated, is capable of metastasis or spreading to other parts of the body. The tumor is highly curable if its growth is restricted to the eyes only, the outlook declines with the increase in the spread of the Cancer cells.
The Retina is a thin layer of tissues at the back of the eyeball that contains cells sensitive to light. It is the light-detecting tissue of the eye.
A baby’s eyes start developing in the womb early in the first trimester of pregnancy. Retina i.e the light detecting part of the eye is formed by rapidly growing cells called Retinoblasts. These growing cells eventually mature to form the retina. In some rare scenario, the growth of retinoblast cells goes on abnormally forming a tumor in the eye.
These tumors may continue to grow, filling almost the entire vitreous humor (the jellylike substances the fills the eyeball). These tumors can also break off and spread to other parts of the eye, and eventually to other distant organs of the body.
Retinoblastoma is a rare disease and is indicated by a white dot on the retina and a squint. It accounts for almost 2% of all cancer occurrences in children below the age of 15. Globally, there are 11 cases per million children below 5 years of age, who have retinoblastoma. It may relieve the mind of many to know the rarity of this disease.
However, a recent survey by AIIMS revealed that the occurrence rate of Retinoblastoma among Indian children is rapidly increasing. Statistics suggest that almost 20,000 new cases of the disease are reported every year. 9-10 % of all Pediatric Cancer patients in India have Retinoblastoma. Though the incidences are increasing at an alarming rate, yet it can be cured when detected early. Median age at diagnosis was 2 years for boys and 1 year for girls with unilateral retinoblastoma; it is less than 12 months for bilateral disease.
For a country of 3120 crores, the number of cases reported might seem small when compared with breast cancer or other head and Neck cancer. Hence, opening with such information puts it in proper perspective.
A risk factor is anything that affects a person’s chance of getting a disease such as cancer. There are very few known risk factors for Retinoblastoma.
Most children diagnosed with retinoblastoma are younger than 3 years old. In most cases, hereditary retinoblastomas are found during the first year of life, while non-inherited Retinoblastomas tend to be diagnosed in 1- and 2-year-olds. Retinoblastomas are rare in older children and in adults.
40% of Retinoblastoma patients have a genetic defect that leads to multiple tumors in one eye or both eyes. This is known as hereditary or germline retinoblastoma. These patients are typically diagnosed before 1 year of age. Patients with hereditary Retinoblastoma may pass this disease to their children.
It is more common in boys than girls.
60% of patients have a nonhereditary form of retinoblastoma. Each of these patients develops a tumor in only one eye. Nonhereditary patients are diagnosed on average around 2 years of age.
Since the causative and risk factors for Retinoblastoma are all natural and we have no control over them, so it becomes almost impossible to prevent the occurrence of Retinoblastoma Cancer. However, it brings a sigh of relief to know that the success rate of treatment is quite high when the cancer is diagnosed at its early stage. So the best prevention is through early detection.
General eye exam of the eyes of babies at birth and after 6 -12 months helps in detecting any serious congenital problems. Adults are advised to take their babies for a regular eye examination at least once a year or more often if one has any eye issues.
It is very important to stage Cancer for a planned diagnostic and treatment of the disease. Cancer is staged based on the size and location of the tumor(s). Although currently there are several staging systems available, the most convenient method is staging by the location of tumor.
Survival depends on many different factors. It depends on your individual condition, type of cancer subtype, treatment and level of fitness. So it is difficult to predict as to how long a particular Prostate Cancer patient will live.
Retinoblastoma Cancer might be indicated by several symptoms like pain, fatigue or a lump. In case any of these signs are visible it is recommended to visit a doctor and go for an examination.
The treatment depends on the number, position and size of the tumors in the eye. The aim of treatment is first to get rid of the cancer and secondly to try to protect the eyesight. Some treatments may cause changes in the vision in the affected eye.
Different types of treatment are available for patients with retinoblastoma. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials.
For smaller tumors, treatment is given to the eye itself. One of the following methods may be used:
It is the treatment with laser therapy or freezing treatments (cryotherapy) while under anesthesia. These focal therapies may continue even after chemotherapy is complete. Sometimes, the tumors in the eye are small enough to be treated with only focal therapy.
A laser is directed through the pupil and used to heat the tumour. A number of sessions of laser therapy are recommended at intervals of 3 to 4 weeks.
A small radioactive disc is stitched over the tumor on the outside of the eye. The disc needs to stay in place for up to four days while the radiation destroys the cancer cells.
This process uses heat to destroy the cancer cells and may be combined with chemotherapy or radiotherapy, as heat can improve the effectiveness of these treatments. The heat is produced by a laser, which is directed at the tumor.
Anti-Cancer drugs are used to destroy Cancer cells. It may be given before the local treatments mentioned above, to help shrink the tumor and make treatment more successful. Chemotherapy can also be used if cancer has spread to other parts of the body, or if there’s a risk that it may spread. The chemotherapy drugs most commonly used to treat Retinoblastoma are carboplatin, etoposide and vincristine. Some of the most common chemotherapies used are:
If the tumor is very large and the vision in the eye is lost, an operation to remove the eye is recommended. The specialist will only do this if it is absolutely necessary. An artificial eye is then fitted.
Radiotherapy treats Cancer by using high-energy rays from a machine to destroy the Cancer cells while doing as little harm as possible to normal cells. It can be given to the whole eye but does have some effect on the surrounding tissue. Radiotherapy for Retinoblastoma is normally only used when other treatments have not worked well.
Retinoblastoma is a very rare disease having a high curative rate. When detected at an early stage it can be cured with surgery, chemotherapy, focal therapy and radiation without causing much harm to the eyes.
In case of experiencing any of the mentioned symptoms or having a familial history of Retinoblastoma Cancer, a complete diagnostic is recommended once in a year.
The age of the patients is generally very low, so the parents and relatives should take responsibility to keep a vigilant eye on the child’s behavior and consult the doctor in case of any suspicion.