Prognosis and survival for retinoblastoma

A prognosis is the doctorʼs best estimate of how cancer will affect your child and how it will respond to treatment. Survival is the percentage of children with a disease who are alive at some point in time after their diagnosis. Prognosis and survival depend on many factors.

The doctor will look at certain aspects of the cancer as well as characteristics of your child (such as their age and family history of retinoblastoma). These are called prognostic factors. The doctor will also look at predictive factors, which influence how a cancer will respond to a certain treatment and how likely it is that the cancer will come back after treatment.

Prognostic and predictive factors are often discussed together. They both play a part in deciding on a prognosis and a treatment plan just for your child. Only a doctor familiar with your childʼs medical and family history, the type and stage and other features of the cancer, the treatments chosen and the response to treatment can put all of this information together with survival statistics to arrive at a prognosis and chances of survival.

The following are prognostic and predictive factors for retinoblastoma.

Doctors use the stage of retinoblastoma to choose treatment and predict the outcome for a child. There are 3 staging systems that might be used for retinoblastoma.

The International Intraocular Retinoblastoma Classification (IIRC) uses groupings to help predict the likelihood that the eye can be saved with current treatment options. Children in group A have the most favourable prognosis and are most likely to be able to see after treatment.

The International Retinoblastoma Staging System (IRSS) is based on how much cancer remains after surgery to remove the tumour and whether the cancer has spread. The lower the stage of retinoblastoma, the more favourable the prognosis.

The American Joint Committee on Cancer (AJCC) staging system is based on tumour size, whether the retinoblastoma 1 (RB1) mutation is heritable and how much the cancer has spread. The lower the stage of retinoblastoma, the better the expected outcome.

When estimating the prognosis of retinoblastoma, doctors will look at whether the cancer is intraocular, extraocular or metastatic. Intraocular retinoblastoma means that the cancer is only inside the eye and has not spread. Extraocular retinoblastoma means that the cancer has spread outside the eye. Metastatic retinoblastoma means the cancer has spread to other parts of the body, farther from the eye.

Children with intraocular retinoblastoma have a better prognosis than children with extraocular retinoblastoma or metastatic retinoblastoma.

Retinoblastoma that has spread to the brain and spinal cord (called the central nervous system, or CNS) has a worse prognosis than cancer that has spread to other distant locations in the body.

Trilateral retinoblastoma is when pineoblastoma develops along with heritable retinoblastoma in 1 or both eyes.

Pineoblastoma is a type of childhood brain tumour that occurs in the pineal gland. The pineal gland is a gland in the brain that controls the sleep cycle.

Trilateral retinoblastoma has a poorer prognosis than retinoblastoma in 1 eye (called unilateral retinoblastoma) or retinoblastoma in both eyes (called bilateral retinoblastoma).