Staging

Staging is a way of describing a cancer, such as where it is located, if or where it has spread, and if it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the cancer's stage, so staging may not be complete until all the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's prognosis (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. This is called staging, and it helps doctors plan treatment. First, the doctor will determine if the retinoblastoma is intraocular or extraocular:

Intraocular. This means that cancer occurs in one 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 or to other parts of the body.

Several intraocular staging systems have been in use for many years to help doctors plan treatment. However, the recent success of clinical trials (research studies) demonstrating the effectiveness of chemotherapy in shrinking tumors has prompted the development of a newer staging system called the International Classification System.

International (ABC) Classification System

Group A:

• Small tumor(s) confined to the retina
  
  
• None larger than 3 millimeters (mm)
  
  
• None closer than 2 disc diameters (DD) from the fovea (central “pit” of the retina) or 1 DD from the optic nerve
  
  
• No vitreous seeding (tumor floating in the eye) or retinal detachment

Group B:

• Tumor(s) confined to the retina
  
  
• Any location in the retina
  
  
• No vitreous seeding
  
  
• No retinal detachment more than 5 mm from tumor base

Group C:

• Fine diffuse or localized vitreous seeding
  
  
• Retinal detachment: more than Group B and up to total retinal detachment
  
  
• No vitreous/subretinal “snowballs” or masses

Group D:

• Massive vitreous/subretinal seeding
  
  
• Vitreous or subretinal snowballs/masses
  
  
• Retinal detachment: more than Group B and up to total retinal detachment

Group E:

No visual potential, or:

Presence of one or more:

• Tumor in CB/anterior segment
  
  
• Neovascular glaucoma
  
  
• Vitreous hemorrhage (bleeding from the eye)
  
  
• Phthisical/prephthisical (deteriorating) eye
  
  
• Hyphema (blood in the anterior of the eye)/corneal staining
  
  
• Orbital cellulitis-like presentation
  
  
• Tumor anterior to anterior hyaloids