Pediatric and Adult Osteosarcoma: Comparisons and Contrasts in Presentation and Therapy

Abstract

Most data on osteosarcoma is derived from pediatric studies. Although the majority of adult patients with osteosarcoma are young adults, who might be treated in a similar fashion, experience derived from a slightly older population is helpful in directing therapy. We treated a series of 123 patients with osteosarcoma of the extremities with adriamycin and cisplatin as induction therapy. Adriamycin was infused intravenously at 90 mg/m² over 96 h. Cisplatin was infused intra-arterially at 120–160 mg/m² over 2–24 h. Sequential addition of methotrexate and methotrexate plus ifosfamide in subsequent cohorts improved the continuous relapse-free survival of poor responders such that overall survival improvement was noted in the group where therapy was modified by adding both agents to those with <90% tumor necrosis. Patients with chondroblastic osteosarcoma with poor necrosis had a trend towards improved continuous relapse-free survival compared with other patients with conventional osteosarcoma. Histologic variants of osteosarcoma except telangiectatic osteosarcoma had a worse prognosis than those with conventional osteosarcoma. The variants, especially dedifferentiated parosteal osteosarcoma and dedifferentiated well-differentiated intraosseous osteosarcoma are more common in adults than children, accounting for some of the inferior prognosis in adults. Older patients obviously cannot tolerate the doses of therapy given to children and young adults, again decreasing the chances of successful treatment. Patients with secondary osteosarcoma are often much older as are many with osteosarcomas of the pelvis and jaw. These tumors tend to be less responsive. An attempt to intensify therapy in poor-prognosis patients with a three-drug regimen of adriamycin, cisplatin, and ifosfamide with peripheral stem cell support was unsuccessful at prolonging relapse-free survival, and we no longer use that approach.