Long term treatment outcome of conventional high grade osteosarcoma in Hong Kong children and adolescents: from the Hong Kong Paediatric Haematology and Oncology Study Group

Abstract

PURPOSE/OBJECTIVE: To assess long-term outcome in Hong Kong osteosarcoma children and adolescents treated with a standard region-wide protocol. MATERIALS AND METHODS: Children and adolescents diagnosed with conventional high-grade osteosarcoma between Nov 1993 and Dec 2010 were included. They were treated according to HKPHOSG Osteosarcoma 1993 protocol. They received 8 weeks of neo-adjuvant chemotherapy with cisplatin, adriamycin and methotrexate, tumour resection at week 10, and post-operative chemotherapy, totally for 27 weeks for good responders with ≥90% tumour necrosis, or for 40 weeks with methotrexate replaced by ifosfamide and etoposide from week 16 for poor responders. RESULTS: Total of 117 patients (65 males, 52 females; median age at diagnosis 12.3, range 0.6*20, years) were treated. Ninety-seven patients (83%) had localized disease; 20 had metastases (pulmonary, n = 15; skip bone, n = 2; multifocal bone, n = 1; bone and pulmonary, n =2). Thirteen patients (11%) had disease progression on treatment. Twenty-eight (24%) patients developed relapses at median time of 1.84 year from diagnosis (range 0.48*12.74). With further definitive surgery, 8 relapsed patients were salvaged and alive without diseases. All patients with relapses not amendable to surgery died. Thirty-seven patients died (progression on treatment, n = 13; after relapses, n = 21; cardiomyopathy, n = 1; early post-operative complication, n = 1; unrelated cause, n = 1). 5-year OS and EFS for patients with localized and metastatic diseases were 77.2% and 68.2%; and 26.9% and 28.1%, respectively. Late complications included renal and tubular function impairment (n = 14), senorineural hearing deficit (n = 10), and second malignancies (n = 3: glioblastoma multiforme, papillary carcinoma of thyroid, therapy related acute myeloid leukaemia). Two patients gave birth to babies 5 and 10 years after initial diagnosis. CONCLUSIONS: Children and adolescents with localized osteosarcoma who receive multiagent chemotherapy under our protocol have a favourable outcome. Prolonged survival and cure is possible for surgically amendable relapses. However, new strategies need to be explored for patients with metastatic diseases.