Five-year results in Ewing's sarcoma. The Scandinavian Sarcoma Group experience with the SSG IX protocol

The first Scandinavian protocol for Ewing's sarcoma, SSG IV, resulted in a local control rate of 74% and 5-year metastasis-free survival (MFS) of 43%. The second protocol, SSG IX, was started in order to improve upon these results. It featured four chemotherapy cycles, each consisting of two courses of VAI (vincristine, doxorubicin, ifosfamide) alternating with one course of PAI (cisplatin, doxorubicin, ifosfamide) at 3-weekly intervals. Total treatment time was 35 weeks. Local therapy was given at week 9. Inoperable or non-radically operated patients received hyperfractionated accelerated radiotherapy 1.5 Gy twice daily between chemotherapy courses to a total dose of 42-60 Gy, depending on surgical radicality and tumour localisation. 88 patients were included (58 male, 30 female, mean age 20 years; range 5-65 years). The tumour (73 M0 and 15 M1) was located centrally in 31 patients (35%), in the extremities in 34 (39%) and other sites in 23 (26%) of cases. The median size of tumour was 10 cm (range 2-23), soft tissue was invaded in 87%. Surgery was the local therapy for 60 (68%) patients: amputation in 8 and local excision in 52. The surgical margins were wide in 35 patients, marginal in 14 and intralesional in 3. Radiotherapy was given to 17 non-radically operated patients postoperatively and to 28 patients with inoperable tumours primarily. Histological responses were evaluated in 52 patients. 9 local recurrences were observed (10%). Distant metastases developed in 24 M0 patients (33%). The estimated 5-year MFS was 58% and overall survival (OS) 70% for M0 and 27% and 28% for M1 patients, respectively. Survival was favourable in patients with non-metastatic extremity tumours (90%) and tumours operated with wide margins (90%). Patients with a total necrosis after chemotherapy had a better OS than those with a partial or poor response (P=0.003). The toxicity (World Health Organisation) was acceptable (gastrointestinal G1-2; haematological G3-4). The SSG IX protocol gave better local control and survival rates than the SSG IV. Whether this is due to a higher therapeutic efficacy of the present protocol cannot be ascertained in this comparison with a historical control.