Treatment of soft tissue sarcoma in childhood and adolescence. A report of the German Cooperative Soft Tissue Sarcoma Study.

BACKGROUND: In the first German soft tissue sarcoma (STS) study, CWS-81, 344 patients younger than 19 years of age who had previously untreated soft tissue sarcoma were studied. For this analysis, there were 218 patients with chemosensitive STS (Group A: rhabdomyosarcoma [RMS], synovial sarcoma, extraosseous Ewing sarcoma, leiomyosarcoma, undifferentiated sarcoma, and malignant peripheral neuroectodermal tumor) who could be studied for a minimum potential follow-up time of 6 years.
METHODS: A staging system based on the postoperative extent of the disease was used. The chemotherapy for Stage I-III disease consisted of vincristine, dactinomycin, cyclophosphamide, and doxorubicin (VACA). Patients with metastatic disease and patients with Stage III disease who failed to respond to VACA were given ifosfamide instead of cyclophosphamide. The definitive procedure for local tumor control (either no radiation exposure, 40 Gy, or 50 Gy) for patients with Stage II-III disease depended on the tumor status at second-look surgery after 16 weeks of chemotherapy.
RESULTS: The rates of disease-free survival (DFS) and survival after 5 years was 61% +/- 4% and 57% +/- 4%, respectively, in group A; for patients with nonmetastatic tumors (Stages I-III), the rates were 69% +/- 4% and 72% +/- 4, respectively. Patients with nonmetastatic rhabdomyosarcoma had a similar prognosis: the survival rate was 73% +/- 4%, and the DFS rate was 68% +/- 4%. There was no difference in prognosis between patients with Stage I and and those with Stage II disease (DFS rate, 88% +/- 5% and 88% +/- 6%, respectively). The DFS rate for patients with Stage III disease was 54% +/- 5% and for those with Stage IV, 11% +/- 5%. Lack of local tumor control was the primary cause of therapy failure: 10% of patients with localized disease did not achieve complete remission, whereas 18% who were in complete remission experienced local relapse. The most important prognostic factors were tumor size (P = 0.005) and the degree of tumor regression after primary chemotherapy (P = 0.007). The prognosis also differed according to primary site: paratesticular tumors had the best prognosis, whereas tumors located in the parameningeal regions of the head and neck had the worst prognosis (DFS rate, 96% +/- 4% versus 49% +/- 7%, respectively).
CONCLUSIONS: The following conclusions were drawn from the CWS-81 study: (1) intensive chemotherapy (VACA for 35 weeks) provides long-term control for most patients with Stage I-II disease; (2) patients with primary unresectable tumors (i.e., Stage III) who achieve complete remission with chemotherapy alone have the same prognosis as patients with postoperative disease of Stages I and II; (3) tumor size and the degree of tumor regression after primary chemotherapy influence outcome and thus can be used as a basis for risk-adapted therapy.