Predictive factors of disease-free survival for non-metastatic osteosarcoma of the extremity: An analysis of 300 patients treated at the Rizzoli Institute

Background: To identify predictive factors of disease-free survival (DFS) i n patients with non-metastatic osteosarcoma of the extremity, treated with primary chemotherapy and delayed surgery. Patients and methods: The relationship between patient-related and treatmen t-related factors and prognosis was evaluated in 300 patients treated from 1986 to 1992 according to chemotherapy protocols based on high-dose methotr exate, cisplatin and doxorubicin, with the addition of ifosfamide in the po st-operative phase. Univariate and multivariate analyses of prognostic fact ors for disease-free survival were performed. Results: With a median follow-up of 9.2 (4.4-12) years, eight-year DFS was 59% (95% confidence interval (95% CI): 54-64.9). Univariate analyses showed that tumor volume greater than or equal to 150 ml (P= 0.002), histologic s ubtype (P = 0.028), age > 12 years (P = 0.044), high serum lactate dehydrog enase (P = 0.044) and alkaline phosphatase (P = 0.064) levels adversely aff ected DFS. Gender of patients and site of tumor did not influence DFS. No d ifferences in DFS were found among the three chemotherapy protocols, wherea s the use of limb-sparing surgery vs. amputation or rotation plasty (P = 0. 006) and a good histologic response to primary chemotherapy (P = 0.014) pos itively correlated with DFS. After multivariate analyses, tumor volume grea ter than or equal to 150 ml (P = 0.028), age > 12 years (P = 0.051), and hi stologic subtype (P = 0.052) retained prognostic significance. Conclusions: In patients with non-metastatic osteosarcoma of the extremity treated with neoadjuvant chemotherapy, the disease-free survival is signifi cantly influenced by tumor volume, age, and histologic subtype.