[The long-term treatment outcomes of adult osteosarcoma].

: Osteosarcoma is the most common primary bone tumor. Treatment of osteosarcoma patients is based on chemotherapy as well as surgical resection of primary tumor and distant metastases. Lung metastases are the primary cause of death in this group of patients. AIM: The aim of this study is to summarize the 20 years of osteosarcoma treatment outcomes in the Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology in Warsaw. MATERIALS AND METHODS: Our analysis included clinical data of 299 osteosarcoma patients aged between 14 and 81 years (median 32) treated in Maria Sklodowska-Curie Memorial Cancer Center between 1998 and 2016. The standard therapeutic protocol included perioperative anthracycline-based chemotherapy and surgical resection of primary tumor and distant metastases. The statistical analysis was performed using Kaplan-Meier estimator, log-rank test and Cox proportional hazards model. RESULTS: In analyzed group 38 (13%) patients had distant metastases at the diagnosis. The tumor size was greater than 8 cm in 61% of cases. In the histopathological assessment the most prevalent subtype was the conventional one (diagnosed in 76% of cases) and histological grade 3 (79%). The 5-year survival rate for patients with localized disease reached 46%. The negative prognostic factors included: distant metastases at diagnosis, axial location of primary tumor, unresectability of the primary lesion, higher histological grade, and older age of patients. CONCLUSIONS: The best results of the treatment of osteosarcoma patients are achieved with multidisciplinary treatment, and when the reference center supports other healthcare providers in management of diagnostic and treatment procedures of osteosarcoma patients.