Treatment outcome of osteosarcoma after bilateral retinoblastoma: a retrospective study of eight cases

Aims To analyse clinical characteristics and treatment outcomes of osteosarcoma that developed in survivors of bilateral retinoblastoma. Methods Three institutions participated in this retrospective study. Among survivors of bilateral retinoblastoma who were diagnosed and treated between 1995 and 2012, 8 cases (4 male, 4 female) of osteosarcoma were identified. Medical records were thoroughly reviewed. Results Median age at diagnosis of bilateral retinoblastoma was 8.5 months (range 1.4–18.4 months). Treatment modalities for retinoblastoma were: enucleation+chemotherapy+radiotherapy (n=6); chemotherapy combined with focal therapy (n=1); and chemotherapy+radiotherapy (n=1). Median radiotherapy dose was 46.5 Gy (range 45–54 Gy). Median age at diagnosis of osteosarcoma was 8.9 years (range 5.4–20.3 years). Median interval between retinoblastoma and osteosarcoma was 8.2 years (range 5.0–20.0 years). Tumour locations were femur (n=5), tibia (n=1), mandible (n=1), and nasal cavity (n=1). Two patients presented with lung metastasis. Seven patients received multimodal treatment, and treatment was refused in 1 patient. After diagnosis of osteosarcoma, the patients were followed for a median of 17.3 months (range 4.4–56.4 months). The 2-year overall survival and event-free survival rates were 56.3±19.9% and 33.3±18.0%, respectively. At the time of analysis, 5 patients remained alive, and 2 of them were on therapy. Of the 3 surviving patients without evidence of disease, 2 received high dose chemotherapy with autologous peripheral blood stem cell support. Conclusions Our data could be used as a basis for future studies aimed at reaching consensus about long term follow-up and treatment guidelines for this genetically susceptible group of patients.