Retinoblastoma (Cancer of the Eye)
What is retinoblastoma?
Retinoblastoma is a type of pediatric cancer that develops on the retina in the eye. Your retina works with your brain to help you see. The retina is located in the back of your eye. It has layers of cells that sense light and send information to your brain.
Retinoblastoma almost always develops in children under age 5. Retinoblastoma treatments include cryotherapy, chemotherapy, radiation and surgery. The outlook depends on several factors, including the tumor’s size and location and whether the cancer has spread. If the tumor hasn’t spread beyond the eye, most children with retinoblastoma live cancer-free after treatment.
How common is retinoblastoma?
Retinoblastoma is very rare. About 200 to 300 children are diagnosed with retinoblastoma every year. It affects boys and girls equally.
Most often, the condition affects one eye. In about a quarter of cases, both eyes are affected.
What are the stages of retinoblastoma?
Healthcare providers classify retinoblastoma using a process called staging. They consider the tumor’s location and whether it has metastasized (spread) to other parts of the body, such as the brain, bones or organs. Most retinoblastoma tumors are detected before they spread to the rest of the body.
Your child’s team of providers uses staging information to select the most appropriate treatment plan. Retinoblastoma stages include:
- Stage 0: The tumor is only in the eye. Healthcare providers can treat the cancer without surgery.
- Stage I: The tumor is only in the eye. Providers can treat the cancer by removing the eye. No cancer cells remain after treatment.
- Stage II: The tumor is only in the eye. Cancer cells remain after the eye has been removed, but the cells are so small they only appear under a microscope.
- Stage III: The cancer spreads to tissues surrounding the eye socket (stage IIIa). Or it spreads to lymph nodes in the neck or ear (stage IIIb). Lymph nodes are glands that help the body fight infection.
- Stage IV: The cancer spreads to other parts of the body. Cancer that spreads may affect the bones or liver (stage IVa) or the brain or spinal cord (stage IVb).
What causes retinoblastoma?
A genetic mutation (a change in the child’s genes) causes retinoblastoma. The gene that causes retinoblastoma is called RB1. The mutation causes cells in the eye to grow uncontrollably, forming a tumor. Around 40% of the time, the child inherits the RB1 mutation from a parent (heritable retinoblastoma). In about 60% of cases, the gene change occurs spontaneously. In those cases, healthcare providers aren’t sure what caused the genetic mutation (nonheritable retinoblastoma).
About 60% of children with heritable retinoblastoma will develop tumors in both eyes (bilateral) and 30% develop a tumor only in one eye. The remaining 10% of children may not develop retinal tumors, but are carriers of the gene. In children who develop tumors in both eyes, the tumors may form at the same time or they can grow months or years apart. Children who have nonheritable retinoblastoma develop tumors in only one eye (unilateral).
What are the symptoms of retinoblastoma?
Most often, the first sign of retinoblastoma is a change in the way the eye looks. Symptoms can affect one eye or both eyes. Retinoblastoma symptoms include:
- White pupil (leukocoria): Leukocoria is usually the first sign of retinoblastoma. The pupil (the round, black center of the colored part of the eye) appears white or cloudy. It may always be dilated. The pupil may look white at certain angles or in a photo that used a flash (pupils usually look red in a flash photo). Rarely, pupils are different sizes.
- Crossed eyes (strabismus): Eyes may appear misaligned, or one eye turns in a different direction than the other. Strabismus can range from mild to severe.
- Red or inflamed eyes: Inflammation and irritation can appear anywhere on the eye. The eyes may hurt or be sensitive.