When an eye is removed, a pathologist carefully examines it under a microscope for signs of cancer.
In particular, the pathologist and doctors treating your child’s retinoblastoma want to know if cancer has spread to:
- the optic nerve
- the anterior chamber (front of the eye)
- the choroid (second outermost layer of the eye)
- the sclera (outermost layer of the eye)
The pathologist sends a report to your child’s ophthalmologist, detailing their findings. The ophthalmologist and oncologist will use the report to decide whether your child needs more treatment, and if so, which therapies are most appropriate.
The Results
You will be given an appointment to meet with the ophthalmologist a few weeks after your child’s surgery. At this appointment, the doctors will discuss the pathology results and whether any further treatment is required.
If the cancer has not spread, no further treatment is needed for that eye. The other eye may still need treatment if it contains cancer. If cancer has spread to outer layers of the eye or the optic nerve, more treatment is needed.
Post Enucleation Therapy
Treatment is given after surgery for three reasons:
- the pathologist has seen signs that some cancer cells may have escaped the eye
- the pathologist has found evidence that cancer has spread outside the eye
- the doctors have diagnosed cancer outside the eye from tests such as MRI, lumbar puncture, bone marrow aspiration and physical examination.
High Risk Features
When chemotherapy is prescribed because there is a high risk of cancer spread, it is called adjuvant chemotherapy, and is given to prevent recurrence. Usually treatment consists of 4-6 cycles of chemotherapy.
When appropriate therapy is given, and your child receives all prescribed therapy with close follow up, the chance of cure is very high.
Extraocular Retinoblastoma
If cancer has already spread outside the eye, treatment will depend on where it has spread, and how far. Radiotherapy may be prescribed in addition to chemotherapy when cancer cells have spread to the orbit (tissues surrounding the eye), or along the optic nerve beyond the lamina cribrosa (the point at which the nerve leaves the eye).
If cancer has spread far along the optic nerve or into the brain, your child may be given chemotherapy directly into the cerebrospinal fluid (fluid bathing the brain and spine). This intrathecal chemotherapy is given by lumbar puncture or via an ommaya reservoir (a catheter inserted in a ventricle of the brain, attached to a reservoir implanted under the scalp).
Some children also receive a stem cell transplant. Stem cells are removed from the child’s peripheral blood and returned after super high dose chemotherapy. When cancer invades the bone marrow, stem cell transplant is usually not possible.
Stem cell transplant is highly complex, expensive, and unavailable in most countries.
The chances of curing children with extensive cancer, even with sophisticated therapies, is very poor. This is why early removal of the eye is vital to save the child’s life.
Further Reading
From our blog, August 2017: The Anatomy of Retinoblastoma Pathology
