Pre-Enucleation Chemotherapy in Advanced Intraocular Retinoblastoma. Central America Follow Up: AHOPCA II

57a Purpose: A significant percentage of patients in Central America present with buphthalmos, carrying a high risk of globe rupture and orbital contamination. In 2007, AHOPCA introduced chemotherapy before enucleation in children with buphthalmos.Methods: Patients with advanced intraocular disease were considered standard-risk and underwent enucleation. Those with diffuse invasion of choroid, postlaminar optic nerve, or anterior chamber invasion received 4-6 cycles of adjuvant chemotherapy (vincristine, carboplatin, etoposide). Patients with buphthalmos or perceived to be at risk for abandonment were considered high-risk, given 2-3 cycles of chemotherapy before enucleation to compete 6 cycles regardless of pathology. All cases were discussed via online meetings.Results: From 2007 to 2014, 396 patients were enrolled; 240 had IRSS stage I (174 unilateral). 143 had upfront enucleation, 95 had pre-enucleation chemotherapy, 1 is pending enucleation and 1 abandoned before enucleation. The standard-risk group 69 had risk pathology and 76 had no risk factors; 125 had no events, 5 abandoned 11 relapsed/progressed and 2 died of toxicity. Of 95 high-risk group, 8 abandoned, 20 relapse/progressive, 6 had toxic deaths and 61 are alive at last follow-up (median time of 4 years). Of high risk group, 55 were unilateral, 82% are alive. At 7 years OS (abandonment-censored) was 95±0.02 and 79±0.04 for standard-risk and high-risk (p=0.008).Conclusion: AHOPCA addressed advanced intraocular disease with an innovative approach. In eyes with buphthalmos and patients with risk of abandonment, neo-adjuvant chemotherapy is effective, when followed by post-enucleation chemotherapy. This approach avoids ocular rupture and intensified therapy, and reduces refusal/abandonment rate.AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST: No COIs from the authors.