Cross-Sectional Profiling of Aqueous Humor VEGF-A Reflects the Tumor and Ocular Microenvironment in Retinoblastoma

Purpose: Vascular endothelial growth factor A (VEGF-A) is a key mediator of tumor angiogenesis. This cross-sectional study quantified aqueous humor (AH) VEGF-A in retinoblastoma (RB) eyes and retrospectively evaluated its association with clinical features. Methods: This study analyzed 60 AH samples: 54 from 49 RB eyes and 6 from age-matched controls with congenital cataract. From pretreatment RB eyes, six samples were collected prior to globe-salvaging treatment and five immediately after primary enucleation (PE). From post-treatment eyes, 12 samples were collected at secondary enucleation (SE), 12 during active treatment (TX), and 19 at 6 months after treatment (END). VEGF-A was measured using the Olink Proximity Extension Assay and reported as absolute concentrations (pg/mL). Results: VEGF-A concentrations (median and interquartile range [IQR]) were 259 (95% confidence interval [CI] = 140-423, IQR = 115-568) in the RB cohort, compared with 149 (95% CI = 39.8-318, IQR = 61.3-208) in cataract controls. Post-treatment levels were significantly lower than pretreatment levels (median = 182, 95% CI = 121-310, IQR = 110-423 vs. median = 1380, 95% CI = 278-18,100, IQR = 467-12,400, P < 0.001). Among treated eyes, SE samples had higher VEGF-A than END samples (median = 506, 95% CI = 120-1010, IQR = 207-926 vs. median = 129, 95% CI = 79.5-212, IQR = 79.5-212, P = 0.007). Conclusions: AH liquid biopsy was a high-yield source of VEGF-A in RB. VEGF-A concentrations were highest during primary enucleation and normalized after treatment completion. These findings support that aqueous VEGF-A reflects the intraocular microenvironment, warranting further validation to improve our understanding of its role in disease progression in RB.