Developing a prognostic model for patients with localized osteosarcoma treated with uniform chemotherapy protocol without high dose methotrexate: A single-center experience of 237 patients

BackgroundStudies of baseline prognostic factors in patients with localized osteosarcoma treated without high dose methotrexate are limited. MethodsThis is single-institutional review of localized osteosarcoma patients treated without high dose methotrexate between June 2003-December 2012. A multivariate analysis of impact of baseline and treatment characteristics on outcome was performed and a prognostic model was developed based solely on baseline factors for predicting event-free survival (EFS) and overall survival (OS). ResultsOf 237 patients with median age of 17 years (range 2-66 yrs), neoadjuvant chemotherapy (NACT) was administered in 220 (92.82%) patients. Post NACT, 200/237 (84.38%) patients underwent surgery. At 30 months median follow-up, 5-year EFS and OS were 36.600.03%, and 50.33 +/- 0.04%, respectively. In multivariate analysis, baseline factors including duration of symptom >4 months (P<0.001) and good performance status (PS) (P<0.001) predicted better EFS whereas good PS (P=0.01) and normal serum alkaline phosphatase (SAP) (P=0.03) predicted better OS. The 5-year EFS without any risk factor (symptom duration <4 months, PS>1) was 58.7 +/- 0.1%, with either one factor 31.5 +/- 0.1% and with both factors 21.9 +/- 0.1%. The 5-year OS without any risk factor (PS>1, elevated SAP) was 66.9 +/- 0.1%, with either one factor 57.9 +/- 0.1% and with both factors 25.6 +/- 0.1% ConclusionsThis prognostic model assists in categorizing risk-groups within localized osteosarcoma. J. Surg. Oncol. 2015;112:662-668. (c) 2015 Wiley Periodicals, Inc.