Retinoblastoma - Childhood: Stages

Approved by the Cancer.Net Editorial Board, 09/2022

ON THIS PAGE: You will learn about how doctors describe a cancer’s growth or spread. This is called the stage. Use the menu to see other pages.

What is cancer staging?

Staging is a way of describing where the cancer is located, if or where it has spread, and whether it is affecting other parts of the body.

Doctors use diagnostic tests to find out the cancer's stage, so staging may not be complete until all the tests are finished. Knowing the stage helps the doctor recommend the best kind of treatment and can help predict a patient's prognosis, which is the chance of recovery. There are different stage descriptions for different types of cancer.

After a retinoblastoma has been found, the doctor will determine the extent of disease in the eye and if the disease has spread outside the eye. First, the doctor will determine if the retinoblastoma is intraocular or extraocular.

  • Intraocular. This means that cancer occurs in 1 or both eyes, but has not spread into surrounding tissues or other parts of the body.

  • Extraocular. The cancer has spread to tissues around the eye(s) or to other parts of the body.

For intraocular retinoblastoma, there is an additional staging system to help doctors plan treatment. This system is called the International Classification System for Intraocular Retinoblastoma. 

Intraocular retinoblastomas are classified as Group A through E, based on the extent of the tumor growth and the cancer's effects on the eye. The group classification also indicates the chance that the affected eye or eyes can be saved with treatment. 

This page provides detailed information about the system used to find the stage of retinoblastoma.

International Classification System for Intraocular Staging

Group A:

  • Very low risk of losing the affected eye(s)

  • Small tumors, 3 millimeters (mm) or smaller

  • Tumors are only in the retina, the layer of tissue at the back of the eye

  • Tumors are not near the foveola (the central "pit" of the retina) or the optic nerve

  • No tumors are floating in the eye, known as vitreous seeding. Vitreous seeding is when the tumors have spread into the vitreous, which is a clear, gel-like fluid that fills the eye.

  • No retinal detachment, an emergency situation where the retina is pulled away from its normal position

Group B:

  • Low risk of losing the affected eye(s)

  • One or more tumors are larger than 3 mm

  • Tumors are only in the retina

  • No vitreous seeding

  • No retinal detachment more than 5 mm from the tumor base

Group C:

  • Moderate risk of losing the affected eye(s)

  • Tumors are well-defined

  • Some spread of tumors under the retina, known as subretinal seeding

  • Tumors may have also spread into the vitreous

  • There is retinal detachment, and it is more than 5 mm from the tumor base up to a complete retinal detachment 

Group D:

  • There is a high risk of losing the affected eye(s)

  • Tumor spread is extensive into the vitreous/beneath the retina 

  • Vitreous or subretinal snowballs/masses

  • There is retinal detachment, and it is more than 5 mm from the tumor base up to a complete retinal detachment

Group E:

Intraocular retinoblastomas that are classified as group E have damaged the eye extensively. There is almost no chance of saving the affected eye(s).

  • Large tumor(s) extending toward the front of the eye

  • Neovascular glaucoma. Glaucoma is damage caused by pressure within the eye. With neovascular glaucoma, this pressure is caused by new blood vessels growing in the front part of the eye as a result of the tumor.

  • Vitreous hemorrhage, which is bleeding from the eye

  • Phthisical/prephthisical eye, which is a condition where the eye shrinks and deteriorates 

  • Hyphema, which is blood in the front of the eye/corneal staining

  • Orbital cellulitis-like presentation, which means it looks like there is an infection in the eye, but no infection is present

  • Tumor anterior to anterior hyaloids, which means the tumor is behind the thin membrane that separates the vitreous from other parts of the eye

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Extraocular staging

This staging system applies to retinoblastoma that has spread outside of the eye, either to the tissues around the eye(s) or the central nervous system (CNS), bone marrow, or lymph nodes. The information below also includes the basics of how each stage is treated. There is more detailed information in this guide’s Types of Treatment section.

Stage 0 (zero). This means that the cancer is in the eye (called intraocular) and has not spread outside of the eye. Patients with stage 0 disease should be classified based on the International Classification System, outlined above. The general approach is conservative treatment for this stage with no additional adjuvant therapy, meaning no additional treatment after surgery.

Stage I. A classification of stage I means that the eye has already been removed and there is some microscopic spread to the optic nerve. These patients need adjuvant chemotherapy after surgery.

Stage II. This stage means that the tumor has spread to the optic nerve or the sclera, which is the white part of the eye. Patients with this stage need adjuvant chemotherapy and possibly radiation therapy.

Stage III. This means that the cancer has spread to the lymph nodes or the bony cavity that surrounds the eyeball. It is divided into 2 substages, called stage IIIa and stage IIIb, depending on where the tumor has spread. The treatment for this stage involves both chemotherapy and radiation therapy.

Stage IV. In stage IV, the tumor has spread to distant areas of the body outside the eye via the lymphatic system and blood vessels. Stage IV is divided into substages of IVa and IVb. Stage IVb is further divided into IVb1, IVb2, and IVb3, depending on the location of the spread. This stage of extraocular retinoblastoma is treated with high-dose chemotherapy followed by stem cell rescue. This means that the child’s stem cell/bone marrow cells are replaced with healthy cells. Learn more about bone marrow/stem cell transplantation. Radiation therapy may also be used in addition to high-dose chemotherapy for some children with stage IV disease.

Recurrent. Recurrent cancer is cancer that has come back after treatment. If the cancer does return, there will be another round of tests to learn about the extent of the recurrence. These tests and scans are often similar to those done at the time of the original diagnosis.

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Information about the cancer’s stage will help the doctor recommend a specific treatment plan. The next section in this guide is Types of Treatment. Use the menu to choose a different section to read in this guide.