Long-term results of the Spanish Protocol SO-95 for the treatment of non-metastatic high-grade osteosarcoma of the extremities in children

The long-term results of the Spanish Study Protocol SEOP-SO-95 for treatment of localised osteosarcoma of the extremities in children were evaluated. One hundred consecutive patients under 18 years of age from 22 institutions were enrolled from January 1995 to December 2000. Immunohistochemical expression of p53, HER/erbB-2 and P-glycoprotein were retrospectively studied in 27 patients. Treatment consisted of: preoperative chemotherapy with doxorubicin, cisplatin, high-dose methotrexate with leucovorin rescue and ifosfamide for 14 weeks; surgery of primary tumour in week 16; postoperative chemotherapy with the above-mentioned drugs for 25 weeks. With a median follow-up of 124 months (range 84-158 months), 69 patients (69%) were continuously event-free survivors; the 10-year probability of event-free survival (EFS) was 62%. Conservative surgery was performed in 85% of patients. Twenty-six patients had local recurrence or distant relapse. The median time to recurrence/relapse was 27 months (range 17-93 months). The local recurrence rate was 7% (7 of the 100 patients); 4 had wide surgical margins, 2 marginal and 1 intralesional. Four patients died as a result of chemotherapy-related toxicity and 1 developed a second neoplasia (acute myeloid leukaemia). p53 expression and HER2/erbB-2 expression showed no effect on survival or EFS. This therapeutic protocol achieved good oncologic and orthopaedic results. We observed a significant treatment-related toxicity.