Purpose: The prognosis of osteosarcoma occurring as a second malignant disease (OS-SMD) is thought to be poor. We attempted to evaluate whether this holds true when OS-SMD is treated with combined modality therapy as developed for primary osteosarcoma and if factors that influence survival might be identified.
Patients and methods: All patients with OS-SMD registered at the Cooperative German-Austrian-Swiss Osteosarcoma Study Group (COSS) study center between 1980 and June 1996 were evaluated for patient- and treatment-related factors, local and systemic outcome, and survival. Therapy was to be given according to contemporary COSS protocols for primary extremity osteosarcoma, including surgery and multiagent chemotherapy.
Results: Thirty patients with OS-SMD were registered (median latency period, 9 years 2 months). The first malignancies had been retinoblastoma (10 patients), sarcoma (10 patients), lymphoma (five patients), carcinoma (four patients), and medulloblastoma (one patient). Treatment for these malignancies had included radiotherapy in 24 patients, surgery in 20, and chemotherapy in 14. Twelve osteosarcomas were located axially and 18 were located in an extremity; 17 were radiation-related. Twenty-seven patients presented with localized disease; three presented with primary metastases (two skip, one lung). All 30 patients received chemotherapy, 29 with multiple drugs. Twenty-eight patients underwent operation. At 7 years, actuarial overall survival, survival free from osteosarcoma progression, and survival free from progression of any cancer were 50%, 34%, and 30%, respectively. In 24 patients with local tumor control, the corresponding values were 63%, 46%, and 38%. All seven local failures occurred in patients with axial osteosarcomas who did not undergo operation with wide surgical margins.
Conclusion: Provided that local tumor control is achieved, OS-SMD treated with combined modality therapy may have a prognosis that approaches that of otherwise comparable primary osteosarcoma.