Retinoblastoma Survival Following Primary Enucleation by AJCC Staging

SIMPLE SUMMARY: Despite the advent of new eye salvage therapies for retinoblastoma in recent years, upfront eye removal remains a life-saving treatment modality. We retrospectively evaluated the AJCC 8th edition cancer staging for prediction of survival of 700 patients consecutively managed with primary enucleation. Overall, 5-year survival was 95.5% and 5-year disease-specific survival was 95.7%. Patients with enucleation <26 days from diagnosis had better survival than those delayed >26 days. The eyes of children with raised intraocular pressure with neovascularization and/or buphthalmos (cT3c) had worse survival than children without this feature (cT2b, cT3b, and cT3d). Children with evidence of extraocular tumor on pathology (pT4) had dramatically worse survival than those with intraocular tumor (pT1 to pT3d). Survival was better for children with high-risk pathology (pT3/pT4) eyes after six cycles of adjuvant chemotherapy than those who underwent fewer cycles. ABSTRACT: Primary enucleation of the eye with retinoblastoma is a widely accessible, life-saving treatment for retinoblastoma. This study evaluated the survival of patients following primary enucleation based on AJCC 8th edition staging. Included were 700 consecutive patients (700 eyes) treated with primary enucleation at 29 Chinese treatment centers between 2006 and 2015. Excluded were patients with less than one year follow-up, bilateral retinoblastoma, clinical evidence of extraocular disease at diagnosis, or prior focal or systemic therapy. The 5-year overall survival was 95.5%, and 5-year disease-specific survival (DSS) was 95.7%. Survival was better when enucleation was <26 days from diagnosis than delayed >26 days (96.1% vs. 86.9%; p = 0.017). Patients with eyes presenting with raised intraocular pressure with neovascularization and/or buphthalmos (cT3c) had worse 5-year DSS (87.1%) than those without (cT2b, 99.1%; cT3b, 98.7%; cT3d, 97.2%) (p < 0.05). The 5-year DSS based on pathological staging was pT1 (99.5%), pT2a (95.5%), pT3a (100%), pT3b (93.0%), pT3c/d (92.3%), and pT4 (40.9%). Patients with pT3 pathology who received six cycles of adjuvant chemotherapy had better 5-year DSS (97.7%) than those with no chemotherapy (88.1%; p = 0.06) and those who underwent 1–3 cycles (86.9%, p = 0.02) or 4–5 cycles (89.3%, p = 0.06). Patients with pT4 pathology who received six cycles of chemotherapy had better 5-year DSS than those with 0–5 cycles (63.6% vs. 16.7%; p = 0.02). Prompt primary enucleation yielded high long-term survival for children with retinoblastoma. The AJCC 8th edition staging is predictive of survival.