Retinoblastoma (Eye Cancer)

The initial sign of retinoblastoma is typically a change in the look of the eye. The symptoms could impact one or both eyes.

Retinoblastoma signs include:

• A white hue is in the center of the pupil when light is shone on it
• Strabismus (crossed eyes that look like they are looking in two separate directions)
• Limited vision
• Swollen eyes
• Red eyes

The International Retinoblastoma Staging System (IRSS) is based on the amount of cancer still present after the surgical removal of the tumor and the spread of malignancy.

1. Stage 0: The tumor is present only in the eye. The tumor is treated nonsurgically, and the eye is not removed.
2. Stage I: The tumor is present only in the eye. The complete eye is removed and no cancerous cells are found in the eye after it is removed.
3. Stage II: The tumor is present only in the eye. The complete eye is removed and cancerous cells are found in the eye after the removal, which is viewed under a microscope.
4. Stage III:
   • Stage IIIA: Cancer has progressed from the eye to tissues around the eye socket.
   • Stage IIIB: Cancer has progressed from the eye to lymph nodes near the ear or in the neck.
5. Stage IV:
   • Stage IVA: Cancer has progressed to one or more parts of the body, such as the bone or liver.
   • Stage IVB: Cancer has progressed to the brain or spinal cord. It may have spread to other parts of the body.

Six types of standard treatment are used to treat retinoblastoma:

1. Cryotherapy: The process of destroying aberrant tissue using extremely cold temperatures. To freeze and destroy cancer cells, a small metal probe is cooled to below zero degrees and placed near the tumor on the surface of the eye. Small retinoblastoma tumors that are close to the front of the eye are typically treated with cryotherapy. Cryosurgery is another name for this treatment.
2. Thermotherapy: The process of killing cancer cells with heat. Thermotherapy is a type of laser therapy. A laser beam is directed via a dilated pupil or onto the exterior of the eye. For tiny tumors, thermotherapy can be used alone. For larger tumors, it can be paired with chemotherapy.
3. Chemotherapy: Employs medications to inhibit the growth of cancer cells by either killing the cells or preventing them from proliferating. Depending on the stage and location of cancer in the body, chemotherapy is administered differently.
   • Systemic chemotherapy:
     • Administered orally, intravenously, or intramuscularly.
     • Shrinks the tumor (chemo reduction) and reduces the need for surgical removal of the eye.
     • After chemoprevention, other treatments such as radiation therapy, cryotherapy, laser therapy, or local chemotherapy could be used.
     • Extra orbital disease demands strong treatment and may call for consolidation with high-dose chemotherapy and autologous stem cell transplantation, either with or without radiation therapy.
     • Could be used to eradicate cancer cells that remain after the initial course of treatment or are external to the eye. Adjuvant therapy refers to treatment provided after the initial treatment to reduce the likelihood of cancer returning.
   • Regional therapy: Administered intrathecally to certain regions, such as the cerebrospinal fluid, an organ, or a bodily cavity (for example, the abdomen) where the cancer is present. Numerous localized chemotherapeutic approaches are used to treat retinoblastoma.
4. Radiation therapy: High-energy radiation, such as X-rays, or other forms of radiation is used to either kill or stop the growth of cancer cells. Radiation therapy is available in two different forms.
   • External radiation therapy: Uses a machine outside the body to administer radiation toward the area with cancer. Certain delivery techniques for radiation therapy can decrease the likelihood of radiation harming neighboring healthy tissue. These include:
     • Intensity-modulated radiation treatment: A form of external three-dimensional radiation therapy that creates images of the tumor's size and structure using a computer. From numerous angles, thin radiation beams of various intensities (strengths) are directed at the tumor.
     • Proton beam radiation therapy: Uses streams of tiny, positively charged protons to deliver high-energy radiation that kills cancer cells. This therapy can decrease the radiation damage to healthy tissue next to a tumor.
   • Internal radiation therapy: Uses radioactive materials that are inserted into or close to the tumor using needles, seeds, wires, catheters, or other devices. The following internal radiation therapy options are available:
     • Plaque radiotherapy: A plaque is a disc with radioactive seeds connected to one side, placed directly on the outside wall of the eye close to the tumor. Radiation is directed to the tumor from the covered side of the plaque with the seeds. The plaque shields the adjacent tissue from radiation.
5. High-dose chemotherapy with stem cell rescue: Chemotherapy is administered in high doses to kill cancer cells. Cancer treatment destroys healthy cells, including those that produce blood. 
   • Stem cell rescue is a process to replace the blood-forming cells. To obtain stem cells:
     • The person’s blood or bone marrow is extracted.
     • The cells are then frozen and preserved.
     • After the chemotherapy is finished, the person receives an infusion of thawed stem cells.
     • These reinfused stem cells grow into (and replenish) the body's blood cells.
   • Extra orbital sickness requires intensive treatment, which may include radiation therapy, autologous stem cell transplantation, consolidation with high-dose chemotherapy, and more.
6. Surgery: Enucleation is the removal of the eye and a portion of the optic nerve, saving the remaining orbital contents and eye muscles intact. A sample of the excised eye tissue will be studied under a microscope to see whether there are any signs that the cancer is likely to spread to other bodily areas. A qualified pathologist, who is familiar with retinoblastoma and other eye diseases, should do this. Enucleation is carried out when there is little to no chance of saving the person’s vision, the tumor is massive or does not respond to treatment or vision does not return after treatment. An artificial eye is fitted in the person.