Retinoblastoma is not treated well?

Retinoblastoma

is an intraocular malignant tumor. If it is diagnosed in the intraocular stage, the tumor is confined to the eyeball and does not invade the surrounding eye or distant tissues. Most of them can be cured and the prognosis is good. If retinoblastoma has developed to the extraocular stage, the tumor invades the eye and other tissues of the body, such as bone marrow and lymph nodes, and may not be cured

.