RESUMO
BACKGROUND: The management of osteosarcoma is challenging especially in lower-income and middle-income countries, and there is an unmet need to evolve efficient and sustainable chemotherapy regimens. METHODS: We compared the outcomes in nonmetastatic osteosarcoma patients treated with three sequential non-high-dose methotrexate-based combination chemotherapy protocols at a single tertiary care center over two decades. The first protocol, OGS-99, involved dose-intense, alternating dyads of three drugs: doxorubicin (Dox), cisplatin (CDDP), and ifosfamide (Ifo). The second protocol, OGS-99 enhanced, included OGS-99 drugs with etoposide and enhanced supportive care. The OGS-12 protocol involved dose-dense administration of eight sequential dyads of Dox, CDDP and Ifo, universal growth factor prophylaxis and targeted nutritional support. Event-free survival (EFS), overall survival (OS), and toxicity were reported using a retrospective chart review in the OGS-99 and OGS-99 enhanced protocols and prospectively in the OGS-12 protocol. RESULTS: A total of 41, 94, and 385 treatment-naïve, consecutive, nonmetastatic patients with extremity osteosarcoma were treated with the OGS-99 (2000-2005), OGS-99 enhanced (2010), and OGS-12 (2011-2016), respectively. At a median follow-up of 19, 86, and 39 months, the five-year EFS rates were 38%, 50%, and 62% in the OGS-99, OGS-99 enhanced, and OGS-12, respectively. The corresponding rates of five-year OS were nonevaluable, 60% and 77%, respectively, with acceptable rates of grade 3-4 toxicities: febrile neutropenia (40%), thrombocytopenia (36%), anemia (51%), and 1% deaths related to toxicity. CONCLUSIONS: Sequential selection of an intelligent, dose-dense chemotherapy regimen together with enhanced supportive care resulted in marked improvement in outcomes of nonmetastatic osteosarcoma and this "small steps-big changes" model deserves wider recognition and usage.
