Prognostic factors for osteosarcoma of the extremity trerated with neoadjuvant chemotherapy: 15-Year experience in 789 patients treated at a single institution

BACKGROUND. The evaluation variables influencing systemic and local recurrence and final outcome are extremely important in defining risk-adapted treatments for patients with nonmetastatic osteosarcoma of the extremity. METHODS. A homogeneous group of 789 patients treated at a single institution between March 1983 and March 1999 with different protocols of neoadjuvant chemotherapy, with a minimum followup of 5 years, were retrospectively evaluated in relation to gender, age, serum levels of alkaline phosphatase, tumor site and size of the pathologic fracture, type of surgery, protocol of chemotherapy, surgical margins, and histologic response to preoperative treatment. RESULTS. The 5-year event-free survival (EFS) and overall survival rates were 60.1% and 67.5%, respectively. Upon univariate analysis, EPS was significantly related to the age of patients, serum value of alkaline phosphatase, tumor volume, histologic subtype, type of surgery, surgical margins, histologic response to preoperative treatment, and chemotherapy protocol. Local recurrences (4.8%) were significantly correlated with surgical margins. The 5-year postrecurrence EFS survival was 17% and was significantly lower for patients who had a local recurrence and metastases than for those with metastases only. Patients who had a recurrence only in the lung had a postrecurrence survival rate significantly better than others, correlated with the number of metastatic nodules and the length of the disease-free interval. CONCLUSIONS. Upon multivariate analysis, age ≤ 14 years, high serum levels of alkaline phosphatase, tumor volume > 200 mL, a two-drug regimen chemotherapy, inadequate surgical margins, and poor histologic response to treatment maintained independent prognostic values on the outcome of nonmetastatic osteosarcoma of the extremities. These factors must be considered when deciding risk-adapted treatments for osteosarcoma patients.