Clinicians at Children’s Hospital Los Angeles have found a way to glean genetic tumour information from the aqueous humour liquid inside the eye, which could provide a novel way to biopsy retinoblastomas.
Most cancers are biopsied and studied so the medical team can design targeted treatments for patients, but this isn’t possible with retinoblastoma as the tumour is like liquid and has cells all over the eye. In the absence of molecular tests, ophthalmologists must look for anomalies in the eye and use ultrasound imaging to diagnose the disease. However, using genetic information biopsied from the aqueous humour – the liquid in the front part of the eye – clinicians may be able to make more accurate diagnoses.
This type of biopsy would also allow researchers to study the disease on a molecular level, which has led to successful new treatments for other cancers.
Retinoblastomas form in the light-detecting cells at the back of the eye, typically in children under two years of age, and can lead to blindness or eye removal.
Retinoblastoma cells also spread easily, and direct biopsy can cause relapse or spread of the disease outside of the eye.
While blood tests can also help make a retinoblastoma diagnosis, these aren’t always accurate or useful.
Children’s Hospital Los Angeles associate director of ocular oncology Dr Jesse Berry said: “It would be easier if we could get tumor information that way, but in our study there was no sign of retinoblastoma in blood samples.
“Many children actually have retinoblasoma tumors in both eyes. If we were to test the blood and find a positive result, we wouldn’t actually know which eye it was from. Instead, aqueous humor biopsies give us specific information for tumors in each eye.”
Berry’s research has also shown that genetic factors can predict treatment success for a given tumour.
Berry said: “Aqueous humor biopsy has potential to become the new standard of care for retinoblastoma. It is our best chance to diagnose and treat these patients on a molecular level.”