Risk Factors for Tumor Recurrence Following Primary Intravenous Chemotherapy (Chemoreduction) for Retinoblastoma in 869 Eyes of 551 Patients.

ABSTRACT

PURPOSE: To identify risk factors for retinoblastoma recurrence following chemoreduction. METHODS: This was a retrospective review of patients with retinoblastoma treated from 1994 to 2019 using chemoreduction with analysis for recurrence using Kaplan-Meier, Cox regression, and logistic regression. RESULTS: There were 869 eyes of 551 patients with retinoblastoma treated with chemoreduction. Follow-up in 556 eyes revealed main solid tumor recurrence (n = 355, 64%), subretinal seed recurrence (n = 244, 44%), vitreous seed recurrence (n = 162, 29%), and/or new tumor (n = 118, 21%) requiring management with focal therapy (transpupillary thermotherapy, cryotherapy) (n = 294, 53%), intra-arterial chemotherapy (n = 125, 22%), intravitreal chemotherapy (n = 36, 6%), plaque radiotherapy (n = 120, 22%), external beam radiotherapy (n = 57, 10%), and/or enucleation (n = 49, 9%). Of all recurrences, 62% were detected by 1 year, 86% by 2 years, 94% by 3 years, 98% by 5 years, 99% by 10 years, and 100% by 15 years. Risk factors for recurrence on multivariate analysis included younger patient age at presentation (odds ratio [OR] = 1.02 [1.00 to 1.04] per 1 month decrease, P = .02), greater International Classification of Retinoblastoma group (OR = 1.24 [1.05 to 1.47] per 1 more advanced group, P = .01), shorter tumor distance to optic disc (OR = 1.11 [1.01 to 1.21] per 1 mm decrease, P = .03), and presence of subretinal seeds (OR = 1.66 [1.09 to 2.53], P = .02). CONCLUSIONS: Retinoblastoma recurrence after chemoreduction is usually detected within the first 3 years following treatment. Younger patients with more advanced, posteriorly located tumors and subretinal seeds at presentation are at increased risk, but recurrence can often be managed with globe-sparing therapy. [J Pediatr Ophthalmol Strabismus. 2020;57(4)224-234.].