Clinical Features Predictive of High-Risk Retinoblastoma in 403 Asian Indian Patients: A Case-Control Study

Abstract

To identify the clinical features predictive of high-risk retinoblastoma on histopathology. Case-control study. A total of 145 cases with histopathologic high-risk features of retinoblastoma and 258 controls without high-risk features. Enucleation and adjuvant chemotherapy. High-risk features on histopathology were defined as the presence of anterior chamber seeds, iris infiltration, ciliary body infiltration, massive (≥ 3 mm) choroidal invasion, postlaminar optic nerve invasion, invasion of optic nerve transection, combined nonmassive choroidal and prelaminar/laminar optic nerve invasion, or scleral/extrascleral infiltration. Of 403 patients who underwent primary enucleation for the treatment of retinoblastoma, 145 (36%) had high-risk features on histopathology (cases) and 258 (64%) had no high-risk features (controls). High-risk retinoblastoma occurred in 16% of (8/50) group D eyes and 39% of (137/353) group E eyes. The histopathologic high-risk features in these 145 patients included anterior chamber seeds (n = 25, 17%), iris infiltration (n = 12, 8%), ciliary body infiltration (n = 17, 12%), massive (≥3 mm) choroidal invasion (n = 69, 48%), postlaminar optic nerve invasion (n = 71, 49%), invasion of optic nerve transection (n = 3, 2%), combined choroidal and optic nerve invasion (n = 17, 12%), scleral infiltration (n = 20, 14%), and extrascleral involvement (n = 8, 6%). The mean number of high-risk features was 2 (median, 2; range, 1-7). The significant clinical features in cases versus controls included prolonged duration of symptoms of >6 months (21% vs. 7%; P < 0.001), poor visual acuity at presentation (74% vs. 64%; P = 0.05), buphthalmos (16% vs. 7%; P = 0.005), secondary glaucoma (47% vs. 15%; P < 0.001), iris neovascularization (46% vs. 22%; P < 0.001), ectropion uveae (39% vs. 14%; P < 0.001), and orbital cellulitis (3% vs. <1%; P = 0.05). On the basis of International Classification of Intraocular Retinoblastoma, group E tumor had a statistically significant higher incidence of high-risk retinoblastoma compared with controls (39% vs. 16%; P = 0.01). Multivariate analysis of clinical features at presentation that predicted high-risk features on histopathology included prolonged duration of symptoms of >6 months (P = 0.008) and secondary glaucoma (P = 0.021). In this study, the clinical features at presentation predictive of high-risk features on histopathology included prolonged duration of symptoms of >6 months and secondary glaucoma. Globe-preserving methods of treatment should be used with caution in patients with these features.