Primary high-grade osteosarcoma: comparison between preadolescent and older patients.

The medical records of patients with high-grade osteosarcoma observed at the authors' institution between 1972 and 1999 were reviewed to study whether osteosarcoma in preadolescent patients has a different biology and a worse prognosis than in older patients. To assess epidemiologic differences, the first analysis evaluated 1,603 patients regardless of tumor stage and site and treatment received. In the second analysis, only 1,136 patients (317 preadolescent and 819 older patients) with nonmetastatic extremity osteosarcoma, treated with the same protocols of chemotherapy, were evaluated to assess differences in prognosis and in the pattern of relapse. Most preadolescents were female (56% vs. 44%, P < 0.0001), and most tumors were located in the extremity (95% vs. 5%, P < 0.001). The 5-year event-free survival (60% [95% CI 53-67%] vs. 58% [95% CI 46-63%]), the overall survival (67% vs. 65%), the rate of amputation (24% vs. 25%), time (21 vs. 22 months) and type of first relapse (systemic 98% vs. 95%, local 2.3% vs. 4.7%) the site of first metastases (pulmonary, 87% vs. 89%), and good histologic response to preoperative treatment (65% vs. 63%) were essentially the same. The authors concluded that there is no need to employ different therapies for the two groups.