The success of primary chemotherapy for group D heritable retinoblastoma

Abstract
Aims: To report the ocular survival and event-free survival following primary multiagent chemotherapy for group D, heritable bilateral retinoblastoma (RB). Methods: The RB database was used to identify children with heritable, bilateral RB treated with primary chemotherapy (six cycles of vincristine, etoposide and carboplatin). Only Group D eyes with more than 12 months’ follow-up were analysed. The timing, number and type of salvage treatments were recorded. Kaplan–Meier estimates for the ocular survival and event-free survival (percentage of eyes that avoided external beam radiotherapy and/or enucleation) were performed as a function of time. Results: Of 18 group D eyes, two (11%) were treated successfully with chemotherapy alone, nine (50%) underwent successful salvage treatment, and seven (39%) were enucleated. The median time from completing chemotherapy to enucleation was 9 months (range 4 to 25 months). Ocular survival was 67% at 2 years. External beam radiotherapy proved successful salvage treatment in five of nine eyes, so the event-free survival was 34% at 2 years. Conclusion: Multiagent chemotherapy alone is rarely sufficient for the preservation of group D eyes. External beam radiotherapy and plaque radiotherapy remain important salvage treatments for advanced, heritable retinoblastoma.