Purpose: To analyze the risk factors and estimate the risk period for tumor recurrence in intraocular retinoblastoma (RB).
Methods: Retrospective study of 60 RB patients.
Results: The mean age at presentation with RB was 16 months (median 11 months; range 1-84 months). Tumor was unilateral in 13 (22%) and bilateral in 47 (78%) patients. Of 83 eyes with intraocular RB, group B (n = 27; 33%) tumors were more common based on International Classification of Intraocular Retinoblastoma. All cases received intravenous chemotherapy as a primary treatment. Over a mean follow-up period of 57 months (median 38 months; range 12-185 months) post-primary treatment, 44 (73%) patients developed tumor recurrence. The mean interval between the completion of primary treatment and first tumor recurrence was 5 months (median 3 months; range 1-24 months). The total duration of treatment for complete tumor control including treatment of tumor recurrences was 20 months (median 19 months; 2-58 months). By multivariate analysis, the factors predictive of tumor recurrence were multiple tumors (p = 0.008) and retinal detachment (p = 0.003) at presentation. Kaplan-Meier estimate of tumor recurrence at 6 months, 1 year, 3 years, and 5 years was 20%, 31%, 68%, and 73%, respectively. There was no tumor recurrence beyond 5 years since primary treatment.
Conclusion: Multiple tumors and retinal detachment at presentation are risk factors for tumor recurrence in RB. Close follow-up is mandatory for at least 5 years since the initiation of treatment for RB.
Keywords: Cancer; Eye; Recurrence; Retinoblastoma; Tumor.