1.P.15 OSTEOSARCOMA TREATMENT WITH BISPHOSPHONATE PAMIDRONATE DISODIUM AS A MAINTENANCE THERAPY

Abstract

Osteosarcoma is the most frequent bone tumor in adolescents and young adults. Already, the bisphophonates were introduced as the first line therapy for metastatic disease as well as the maintenance therapy, but new drugs are still in researchers interest.

Between 2005 and 2008, we have been treated 17 osteosarcoma patients, from 4 till 18 years of age. All patients have been followed up for 11 months average (range 4–18). At the time of diagnosis 15 of them had local disease, and 2 had metastatic disease. They were treated according to EURAMOS protocol. There were two groups of patients; the high risk patients who has received the pamidronat disodium (pamidronat) after the standard postoperative chemotherapy, and the other group who hadn’t received pamidronat. One patient, who had bone and pulmonary metastasis at the diagnosis, received the pamidronat as the first line therapy. We have introduced the 2 mg/kg mothly of pamidronat to 7 patients, median age of 13. Patients have received 8 cycles average of pamidronat (range 4–12). Two patients had to be excluded from therapy due to nephrotoxycity and pregnancy. The patient with metastatic disease, bone and lung metastasis, at the diagnosis, had died, and two patients who had pulmonary metastasis, afer the surgery and second line chemotherapy, showed no disease progression during the pamidronat therapy. In the other group of patients, who hadn’t received the pamidronat, one patient with metastatic disease had died, 2 of them had local reccurence, and 2 died due to disease progession.

Introducing the pamidronat has been a big step forward for osteosarcoma patients, because, according to our results, during the pamidronat therapy they haven’t developed local recurrence and/or disease progression.