[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 prognostic 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 pathologic 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 presented with a pathologic fracture, and 12 patients with metastasis. 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 prognostic factors in our study are mainly associated with late presentation. As in every malignant disease, early admission would provide better survival rates.