Chemotherapy prior to eye removal in pediatric patients with advanced intraocular retinoblastoma may not offer any survival benefits, but timely enucleation—not delaying the procedure to try and salvage the eye—could minimize the risk of metastatic death in children, a new study in Ophthalmology Retina reports.

While the surgical removal of eyes is a well-established method to try and cure advanced intraocular retinoblastoma, in recent years, eyes with more advanced disease have been saved with vision-preserving combinations of chemotherapy and tumor endo-resection through pars plana vitrectomy. However, when the attempted globe salvage fails, enucleation will have already been delayed by the treatments. Delving into the potential impact, a team of researchers from China and Canada studied the effect of delayed enucleation on disease-specific survival of children with advanced retinoblastomas and the histopathology of enucleated eyes.

The study included 554 children who were about 23 months old with advanced retinoblastoma (referred to as Group D and E based on the International Intraocular Retinoblastoma Classification) from 29 Chinese treatment centers.

The investigators reviewed clinical staging, time from diagnosis to enucleation, numbers of chemotherapy cycles, disease-specific survival, histopathology and follow-up.

The study found primarily enucleated eyes had a significantly shorter delay from diagnosis to enucleation than eyes treated with pre-enucleation chemotherapy. Additionally, investigators found decreased survival rates when there were delays between diagnosis and enucleation of more than 3.5 months in Group D and more than two months in Group E.

Compared with primarily enucleated eyes, Group E eyes with one-to-three cycles of pre-enucleation chemotherapy had no significant difference in survival rates, but those who received four or more cycles had worse survival rates. After pre-enucleation chemotherapy, more children in Group E—but not Group D— had high-risk histopathology and worse survival than those primarily enucleated.

Also of note: chemotherapy after eye removal improved survival of children with high-risk histopathology but did not change survival of low-risk children.

This study is an expansion of the investigators’ 2011 research that found a delay of greater than three months from diagnosis to enucleation increased mortality for children with Group E disease.

Zhao J, Feng ZX, Wei M, et al. Impact of systemic chemotherapy and delayed enucleation on survival of children with advanced intraocular retinoblastoma. Ophthalmology Retina. March 4, 2020. [Epub ahead of print].