Abstract: Objective To investigate the prognosis of stage ⅡB osteosarcoma in extremities treated with combined therapy， and the possible prognostic factors. Methods The data of 200 patients of stage ⅡB osteosarcoma were reviewed. Kaplan-Meier method was used to test the overall survival（OS） of osteosarcoma patients. Cox proportionalhazards regression model was employed to analyze the prognostic factors.
Results The 1-，2-and 3-year survival rates were 87.0％， 71.5％ and 51.5％，and the median OS was 37.0 months（95%CI: 25.67-48.33 months）. The univariate analysis showed that OS was significantly related to sex，surgical methods，adjuvant chemotherapeutic cycles，the serum level of alkaline phosphatease（AKP）after neo-chemotherapy and pathological types. Neo-adjuvant chemotherapy had approximate significance，while age had no influence on OS. Moreover，Cox proportional-hazards regression model revealed that adjuvant chemotherapeutic cycles，the serum level of AKP after neo-chemotherapy and pathological types were the independent factors affecting OS. Conclusion Standardization of chemotherapy plays an important role in improving OS in patients with osteosarcoma of stage ⅡB. The patients can be provided with individualized treatment based on pathological types and the serum level of AKP after neo-chemotherapy.