Research and clinical trials are providing hope
Thirty to 40 percent of retinoblastoma cases are hereditary retinoblastoma. It can be found in one or both eyes, and is usually found in younger children. When the disease is found in both eyes, it is always the hereditary form.
Because of the genetic basis of this disease, siblings need to be examined by an eye specialist, and the parents should meet with a genetic counselor. A child with hereditary retinoblastoma also is at greater risk for developing other kinds of cancer elsewhere in the body later in life. These children should continue to have medical check-ups even after the disease has been treated.
This form affects one eye only, and is generally found in older children. There is a slight chance that these children are at greater risk for developing cancer elsewhere in the body later in life. As a result, they should continue to have medical check-ups even after the disease has been treated.
To learn more about retinoblastoma, read “The Rambergs’ Story: Three Generations of Retinoblastoma.”
Parents usually see the first signs and symptoms of retinoblastoma, and this prompts them to seek medical care. They include:
- A white pupil, called “leucocoria.” This may be most evident in pictures where one pupil appears red (normal) and the other appears white.
- One or both, crossed eye(s).
- Poor vision.
- White spots on the colored part — called the iris — of the eye.
- Red, swollen eye
The persistent presence of one or more of these conditions is good cause to immediately get a medical check-up — especially if other family members now have, or have had in the past, vision problems or cancer.
An ophthalmologist (eye doctor) experienced with treating retinoblastoma is the specialist who can diagnose the disease. It is usually done in the hospital by putting the child under general anesthesia so the eye can be thoroughly examined. Among the examination procedures are:
- Applying drops to dilate the pupils so the doctor can see tumors.
- Ultrasound that uses sound waves to make a picture of the retina and expose any tumors growing there.
- CT or MRI scan to make a picture of internal structures of the eye, the optic nerves and the brain.
Once the diagnosis of retinoblastoma is made, the cancer must be “staged.” This is a way of classifying the cancer according to size and number of tumors. As it is unlikely to have retinoblastoma outside of the eye, most staging systems evaluate the extent of tumor within the affected eye or eyes. Accurate staging can help the ophthalmologist predict the vision of the eye and can help the treatment team determine the most appropriate treatment strategy for a child.
Treatment depends on the size, number and location of the tumors, whether one or both eyes are affected, and the age of the child. Treatment options that attempt to cure the patient and preserve vision include the following:
- Chemotherapy: This is the use of drugs to kill cancer cells.
- Cryotherapy: This is the use of extreme cold to destroy cancer cells.
- Photocoagulation: This is the use of laser light to destroy blood vessels that supply nutrients to the tumor.
- Enucleation: Surgery to remove the eye is performed if the tumor is too advanced to be locally controlled with combinations of chemotherapy and other treatment methods.
- Radiation therapy: Uses high-energy radiation from x-rays and other sources to kill cancer cells and shrink tumors. It may come from a machine outside the body — external beam radiation — or from a radiation source implanted into the tumor, or near it. This form is called internal radiation therapy, or brachytherapy.
Treatment by type of retinoblastoma
Treatment depends on whether the cancer is in one or both eyes. If the cancer is in one eye, treatment may be one of the following:
- Surgery to remove the eye (enucleation) is used for large tumors when there is no expectation that useful vision can be preserved.
- Chemotherapy may be used to shrink the tumors in the eyes allowing the ophthalmologist or radiation therapist a smaller area to treat.
- External radiation therapy, photocoagulation, cryotherapy, thermotherapy, or brachytherapy may be used with smaller tumors when there is potential for preservation of sight.
If the cancer is in both eyes, treatment may be one of the following:
- Surgery to remove the eye with the most cancer, and/or radiation therapy to the other eye.
- Clinical trials testing systemic chemotherapy with or without other types of treatment.
- Radiation therapy to both eyes if there is potential for vision in both eyes.
In this condition, the cancer has spread and extends beyond the eye. It may be confined to the tissues surrounding the eye, or it may have spread to other parts of the body. Treatment may be one of the following:
- Radiation therapy and/or intrathecal (into the space between the lining of the spinal cord and the brain) chemotherapy.
- Clinical trials are testing new combinations of chemotherapy drugs, with or without peripheral stem cell transplantation, and different ways of administrating chemotherapy drugs.
Recurrent disease means that the cancer has come back (recurred) or progressed (continued to grow) after it has been treated. It may recur in the eye, the tissues around the eye, or elsewhere in the body. Treatment depends on the site and extent of the spread.
- If the cancer comes back only in one eye and is small, the child may have surgery or radiation therapy.
- If the cancer comes back outside of the eye, treatment will depend on many factors and individual patient needs. Parents may want to consider having their child participate in a clinical trial.