Activity of topotecan in retinoblastoma

Purpose: To report our experience with topotecan in children with relapsed/refractory metastatic and intraocular retinoblastoma. Patients and methods: Topotecan was administered intravenously as a 30-min infusion at a dose of 2mg/m 2 /d for five consecutive days and repeated after three weeks. If obvious progression was detected by physical examination in patients with overt extraocular disease or if progressive disease was noted after fundoscopic examination in patients with intraocular disease, a second cycle was not administered. Response was evaluated at Week 6. Results: Nine patients (6 extraocular, 3 intraocular) were treated from November 1998 to March 2002. A total of 16 cycles were administered. In patients with extraocular disease, there were three partial responses, two cases of stable disease, and one case of progressive disease. Two patients with relapsed/resistant intraocular disease had partial response, allowing local therapy to be performed, and the third patient had progressive disease. The drug was well-tolerated. No patient developed fever or documented infections. No other serious toxicity was found. Conclusion: Topotecan is active in extraocular and relapsed/resistant intraocular retinoblastoma. The role of this drug in the treatment of retinoblastoma should be explored in further studies.