Survival analysis and the effects of prognostic factors in patients treated for osteosarcoma

Objectives: We evaluated long-term treatment results of patients with primary osteosarcoma and the effect of prog-nostic factors on overall survival and disease-free survival. Methods: Between 1995 and 2005, 180 patients (111 males, 69 females; mean age 21+10 years; range 7 to 64 years) were treated for primary osteosarcoma. Overall and disease-free survival rates were analyzed for 165 patients with high-grade osteosarcoma with the Kaplan-Meier method. The effects of potential prognostic factors were assessed, including age, gender, localization, tumor size, primary metastasis on presentation, the presence of patho¬logic fractures, necrosis rate, and infection. All the patients received chemotherapy before and after surgery. The mean follow-up period was 49.7 months (range 6 to 185) months. Results: Sixty-nine patients were below 16 years of age. The most frequent involvement was in the distal femur (47.2%), followed by the proximal tibia (25%). Sixteen patients pre¬sented with a pathologic fracture, and 12 patients with metas¬tasis. The median tumor size was 10 cm. The overall five- and 10-year survival rates were 68% and 60%, and disease- free survival rates were 50% and 44%, respectively. Only the presence of a pathologic fracture and primary metastasis on presentation were found to affect prognosis. Conclusion: The two conditions, primary metastasis and a pathologic fracture, found as the most important prog¬nostic factors in our study are mainly associated with late presentation. As in every malignant disease, early admis¬sion would provide better survival rates.