What is retinoblastoma?
Retinoblastoma is a rare childhood cancer of the eye. It arises from the retina, the nerve tissue in the back of the eye that is sensitive to light. Thanks to advances in diagnosis and treatment, more than 95 percent of children with retinoblastoma that is contained in the eye can now be cured. Retinoblastoma is usually diagnosed before the age of 2, and more than 90 percent of cases are diagnosed by age 5 — it is equally common in boys and girls. Tumor(s) may be present in one or both eyes. They rarely spread to other parts of the body and may be inherited within a family or may occur in a child without any family history of the disease. Retinoblastoma is rare — about 250 to 300 children in the United States are diagnosed each year.
Retinoblastoma | Symptoms & Causes
What are the symptoms of retinoblastoma?
Retinoblastoma symptoms tend to develop before age 2. Keep in mind that these symptoms can be caused by other conditions — for example, leukocoria and poor vision may be caused by a cataract — so it’s important to always see a specialist for a diagnosis.
The most common symptoms include:
- leukocoria: the pupil of the eye appears white instead of the expected red when light shines into it
- strabismus (also called “wandering eye” or “crossed eyes”): one or both eyes don’t appear to be looking in the same direction
- nystagmus: involuntary movement of the eye(s)
- poor vision or change in vision
- pain or redness around the eye(s)
What causes retinoblastoma?
Retinoblastoma is genetic, which means that it is caused by mutations in a gene. These mutations prevent the body from making certain proteins that when working control how cells grow. When these proteins are not made correctly, too many cells can build up in one place and form a tumor.
While all retinoblastoma is genetic, only a proportion are hereditary. About 70 to 75 percent of cases are nonhereditary, meaning that the mutation develops in the child and is not passed on to future generations. This is known as “sporadic retinoblastoma” and usually only one eye is affected. Children with nonhereditary retinoblastoma tend to develop tumors later, and they do not have an increased risk of other tumors.
About 25 to 30 percent of cases of retinoblastoma are hereditary. These children tend to develop tumors at a younger age and are more likely to have tumors in both eyes. Children with hereditary retinoblastoma are also at higher risk of developing other tumors, including childhood tumors in the brain, or osteosarcoma (a tumor of the bone), soft tissue sarcomas, or melanomas later in life.
To determine whether the retinoblastoma is hereditary, all children with retinoblastoma seen at Dana-Farber/Boston Children’s Cancer and Blood Disorders Center are referred to the Pediatric Cancer Genetic Risk Program, a comprehensive program that provides genetic testing and counseling. If hereditary retinoblastoma is identified, further screening recommendations and an invitation to enroll in screening studies may be offered. We also can provide testing of other family members through this program.
Retinoblastoma | Diagnosis & Treatments
How is retinoblastoma diagnosed?
The first step in treating your child is to obtain an accurate and complete diagnosis. In addition to a complete medical history and physical examination, your child’s doctor may order one or more tests to determine the cause of their symptoms. Most often, the tests are performed under general anesthesia, so your child won’t feel a thing. Tests include:
If advanced disease is suspected, other work-ups may be needed, including specialized imaging such as a bone scan, and studies such as a lumbar puncture and evaluation of the bone marrow. Retinoblastoma is usually diagnosed without a biopsy.
In addition to physical exam and imaging procedures, our genetic counselors from the Pediatric Cancer Genetic Risk Program will meet with you and discuss the possibility of taking a blood sample and running tests to look for an abnormal retinoblastoma gene. This allows us to have an informed discussion with you about whether the condition in your child’s case is heritable.
Stages of retinoblastoma
During the workup for retinoblastoma, your child’s doctors will look to determine the size, number, and location of the tumor or tumors, and whether they have spread to the other parts of the body. This is called staging and is an important step in planning treatment
Your team will determine whether the retinoblastoma is intraocular (inside the eye) or extraocular (the cancer has also spread outside the eye).
Recurrent retinoblastoma refers to cases where the tumor comes back after treatment.
After we complete all necessary tests, our experts meet to review and discuss what they have learned about your child's condition. Then we will meet with you and your family to discuss the results and to outline the best treatment options for your child.
How do we treat retinoblastoma?
Since retinoblastoma is usually found before it spreads outside of the sclera (the outer white part of the eye), the condition is highly curable. There are several types of treatment that can save sight in the affected eye.
Traditional forms of treatment for retinoblastoma carry the risk of injuring the eye (for example, when radiation is used) or of causing systemic symptoms, such as a weakened immune system (for example, when IV chemotherapy is used). For these reasons, our retinoblastoma treatment team will utilize intra-arterial chemotherapy whenever it is appropriate for a patient’s tumor.
Intra-arterial chemotherapy is a relatively newer treatment for retinoblastoma in which the chemotherapy is injected directly into the main blood vessel of the eye (the ophthalmic artery). This treatment was designed to minimize the amount of contact the chemotherapy has with the rest of your child’s body, so as to reduce side effects. Even though the total dose of chemotherapy injected is lower than in traditional IV treatment, the dose delivered directly to the eye is much higher, and so may kill more cancer cells in fewer treatments. The eye is uniquely suited to intra-arterial chemotherapy because the blood supply to the eye, in almost all cases, travels through just one feeding artery.
During this procedure, your child is put to sleep by an anesthesiologist. Then the surgeon inserts a thin catheter through a blood vessel in your child’s groin, and feeds it up the arteries of the body to the ophthalmic artery. At this point, the chemotherapy is injected through the catheter directly to the eye. The average number of treatment sessions is three to four for each affected eye, delivered about every four weeks.
Because young children have smaller and more fragile arteries than adults, it is important that children who receive intra-arterial chemotherapy are treated at a pediatric-specific cancer center. At Dana-Farber/Boston Children’s, our interventional neuroradiologists have specialized expertise in working with children, including babies and toddlers, and our complication rates are the lowest published for comparable procedures performed at other centers, including both adult and pediatric centers.
With chemoreduction, chemotherapy is given through an IV. It passes through your child's blood stream and, if successful, causes the tumors to shrink within a few weeks. Depending on which drugs your doctor prescribes, your child may or may not be hospitalized during treatment. Chemoreduction rarely, if ever, cures retinoblastoma when used alone, so additionally treatments such as cryotherapy, thermotherapy, photocoagulation, or radiation also would be needed (see descriptions below).
Surgery is usually reserved for children with advanced retinoblastoma that doesn't respond to other treatments. In these cases, the eye may need to be removed during a procedure called enucleation. While it is theoretically possible for the tumor to return even following this procedure, such cases would be extremely rare.
Enucleation is a relatively simple operation that is performed while your child is under general anesthesia. Following the surgery, the eye is replaced with an orbital implant, and after the eye has healed, an artificial eye — made to match your child's healthy eye — can be worn. Some newer types of implants allow the artificial eye to move, but implants are not yet able to provide vision. Children who have an artificial eye can still participate in sports, as long as they use proper protective eyewear.
Cryotherapy (sometimes called cryosurgery) applies extreme cold directly to the tumor and is used to treat small tumors or additional tumors that develop outside of the original tumor. Cryotherapy is often used together with chemotherapy, or it may be used after radiation therapy.
During cryotherapy, your child is first put to sleep by an anesthesiologist. Then the surgeon uses ultrasound to guide and place a small, extremely cold probe directly onto the tumor. The surgeon takes extreme care to ensure that the surrounding healthy tissue remains unharmed. Cryotherapy may be repeated on several occasions, if necessary.
An advantage of cryotherapy is that it may help prevent the need for enucleation or radiation therapy. The major disadvantages are that cryotherapy may leave a scar which damages future vision and that the procedure is not very effective in treating larger tumors.
Thermotherapy is a method of delivering heat to the eye using ultrasound, microwaves, or infrared radiation. Like cryotherapy, thermotherapy is only useful for very small tumors, and can be combined with chemotherapy or radiation therapy. Thermotherapy leaves a relatively small scar and tends to preserve more vision than cryotherapy.
Photocoagulation, also called light coagulation, is another method for treating small tumors. This technique uses focused light from a laser to destroy the tumor by destroying its blood supply. Photocoagulation is sometimes used in combination with chemotherapy.
Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells.
A targeted type of radiation therapy that involves the temporary placement of a small amount of radioactive material on the part of the eye affected by retinoblastoma.
All treatment types have side effects associated with them. Your care team will discuss side effects and ways to manage them before your child begins treatment.
Dana-Farber/Boston Children’s also offers specialists who deliver complementary or alternative medicines. These treatments, which may help control pain and the side effects of therapy, include:
- therapeutic touch
- herbal supplements
- dietary recommendations
Talk to your child's team about whether complementary or alternative medicine might be a good option for your child.
What is the long-term outlook for children with retinoblastoma?
One hundred years ago, retinoblastoma was almost always fatal. Today, retinoblastoma has one of the highest cure rates of all childhood cancers — about 95 to 98 percent — with more than nine out of every 10 children surviving well into adulthood. Lifelong follow-up is crucial for children with hereditary retinoblastoma who are at risk of developing cancer elsewhere in the body later in life. All children who have received cancer-directed therapy should also be followed for late-effects of treatment. Through the David B. Perini Jr. Quality of Life Clinic, childhood cancer survivors receive comprehensive follow-up evaluations from their cancer care team.
How we care for retinoblastoma
Through our Retinoblastoma Program, children with retinoblastoma receive treatment from a multidisciplinary team of oncologists, ophthalmologists, interventional radiologists, and other subspecialists with expertise in retinoblastoma. Dana-Farber/Boston Children’s Cancer and Blood Disorders Center is an integrated pediatric oncology program that provides all the services of both a leading cancer center and a world-renown pediatric hospital.
We offer the full range of multidisciplinary treatment options for retinoblastoma, including intra-arterial chemotherapy — a recently-developed treatment option that often can provide the most effective retinoblastoma treatment with the fewest side effects. Our neurointerventional radiology team carries out one of the highest volumes of pediatric brain and head and neck angiographic procedures (including intra-arterial chemotherapy) in the world.
Retinoblastoma | Research & Clinical Trials
New types of treatment are being tested through clinical trials. A clinical trial is a research study meant to help improve current treatments or to obtain information on new treatments. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may then become the standard treatment. We also have studies open to address how best to screen children with cancer predisposition syndromes including retinoblastoma.