Delayed Enucleation With Neoadjuvant Chemotherapy in Advanced Intraocular Unilateral Retinoblastoma: AHOPCA II, a Prospective, Multi-Institutional Protocol in Central America

PURPOSE Treatment abandonment because of enucleation refusal is a limitation of improving outcomes for children with retinoblastoma in countries with limited resources. Furthermore, many children present with buphthalmos and a high risk of globe rupture during enucleation. To address these unique circumstances, the AHOPCA II protocol introduced neoadjuvant chemotherapy with delayed enucleation. PATIENTS AND METHODS Patients with advanced unilateral intraocular disease (International Retinoblastoma Staging System [IRSS] stage I) were considered for upfront enucleation. Those with diffuse invasion of the choroid, postlaminar optic nerve, and/or anterior chamber invasion received six cycles of adjuvant chemotherapy (vincristine, carboplatin, and etoposide). Patients with buphthalmos and those with a perceived risk for enucleation refusal and/or abandonment were given two to three cycles of chemotherapy before scheduled enucleation followed by adjuvant chemotherapy to complete six cycles, regardless of pathology. RESULTS A total of 161 patients had unilateral IRSS stage I disease; 102 underwent upfront enucleation, and 59 had delayed enucleation. The estimated 5-year abandonment-sensitive event-free and overall survival rates for the group were 0.81 +/- 0.03 and 0.86 +/- 0.03, respectively. The 5-year estimated abandonment-sensitive event-free survival rates for patients undergoing upfront and delayed enucleation were 0.89 +/- 0.03 and 0.68 +/- 0.06, respectively (P = .001). Compared with AHOPCA I, abandonment for patients with IRSS stage I retinoblastoma decreased from 16% to 4%. CONCLUSION AHOPCA describes the results of advanced intraocular retinoblastoma treated with neoadjuvant chemotherapy. In eyes with buphthalmos and patients with risk of abandonment, neoadjuvant chemotherapy can be effective when followed by enucleation and adjuvant chemotherapy. Our study suggests that this approach can save patients with buphthalmos from ocular rupture and might reduce refusal of enucleation and abandonment.