Background: Intravenous etoposide is widely used in multiagent chemotherapy regimens for intraocular retinoblastoma despite the lack of phase II data documenting its efficacy. Because oral etoposide has been found to be highly effective in patients with relapsed medulloblastoma and neuroblastoma who had previously received intravenous etoposide, we investigated its use for intraocular retinoblastoma.
Procedure: A pilot trial of oral etoposide (50 mg/m2/ day for 21 days) in five children (6 eyes) with relapsed refractory intraocular retinoblastoma was performed. All had previously received chemotherapy, including intravenous etoposide in four patients, and all had received radiation therapy. Three patients (3 eyes) had vitreous seeds. Response was evaluated after one cycle.
Results: No serious acute toxicity was encountered, and no responses were noted. Four patients (5 eyes) had progressive disease. Stable disease was noted in one eye without vitreous disease. One patient developed secondary acute myeloid leukemia 30 months after exposure to oral etoposide.
Conclusions: Oral etoposide was not an effective agent in this population. The role of etoposide in the treatment of higher risk intraocular retinoblastoma deserves further study.