Neoadjuvant chemotherapy for radioinduced osteosarcoma of the extremity: The Rizzoli experience in 20 cases.

Purpose: Evaluate treatment and outcome of 20 patients with radioinduced osteosarcoma (RIO). Because of previous primary tumor treatment, RIO protocols were different from others we used for non-RIO.
Patients and Methods: Between 1983 and 1998, we treated 20 RIO patients, ages 4-36 years (mean 16 years), with chemotherapy (two cycles before surgery, three postoperatively). The first preoperative cycle consisted of high-dose Methotrexate (HDMTX)/Cisplatinum (CDP)/Adriamycin (ADM) and the second of HDMTX/CDP/Ifosfamide (IFO). The three postoperative treatments were performed with cycles of MTX/CDP; IFO was used as single agent per cycle repeated three times.
Results: Two patients received palliative treatment because their osteosarcoma remained unresectable after preoperative chemotherapy. The remaining 18 patients had surgery (7 amputations, 11 resections); histologic response to preoperative chemotherapy was good in 8 patients, poor in 10. At a mean follow-up of 11 years (range, 7-22 years), 9 patients remained continuously disease-free, 10 died from osteosarcoma and 1 died from a third neoplasm (myeloid acute leukemia). These results are not significantly different from those achieved in 754 patients with conventional osteosarcoma treated in the same period with protocols used for conventional treatment. However, this later group had an 18% 3-year event-free survival after treatment of relapse vs. 0% in the RIO group.
Conclusion: Treated with neoadjuvant chemotherapy RIO seem to have an outcome that is not significantly different from that of comparable patients with conventional primary high grade osteosarcoma (5-year event-free survival: 40% vs. 60%, p = NS; 5-year overall survival 40% vs. 67%, p < 0.01).