Treatment of children with metastatic soft tissue sarcoma with oral maintenance compared to high dose chemotherapy: report of the HD CWS-96 trial. Sequential high-dose chemotherapy for children with metastatic rhabdomyosarcoma. High-dose melphalan with autologous stem-cell rescue in metastatic rhabdomyosarcoma.
We prospectively studied the efficacy of high dose therapy (HDT) versus an oral maintenance treatment (OMT) in patients with stage IV soft tissue sarcoma (STS).
                Both groups were pretreated with the CEVAIE combination consisting of carboplatin, etoposide, vincristine, actinomycin D, ifosfamide, and epirubicin. HDT consisted of a tandem cycle of thiotepa (600 mg/m(2)) plus cyclophosphamide (4,500 mg/m(2)) and melphalan (120 mg/m(2)) plus etoposide (1,800 mg/m(2)). This treatment was compared with OMT, consisting of four cycles trofosfamide (10 days 2 x 75 mg/m(2)/day) plus etoposide (10 days 2 x 25 mg/m(2)/day), and 4 cycles trofosfamide (10 days 2 x 75 mg/m(2)/day) plus idarubicin (10 days 4 x 5 mg/m(2)). Eligibility criteria were: diagnosis confirmed by reference pathology, primary stage IV, below 22 years of age, and having completed the study therapy.
                From 96 patients 45 were treated with HDT and 51 with OMT. The main risk parameters were equally distributed in both arms. After a median follow-up of 57.4 months, 11/45 (24.4%) patients in the HDT-arm and 26/51 (57.8%) patients in OMT-arm were alive. Kaplan-Meier analysis demonstrated an overall survival for the whole group of 0.27 (OMT group: 0.52, HDT group 0.27, log rank P = 0.03). The proportional hazard analysis for patients with rhabdomyosarcoma (RMS) or "RMS-like" tumors (77.1% of all patients) demonstrated an independent benefit of OMT on outcome.
                Oral maintenance therapy seems to be a promising option for patients with RMS-like stage IV tumors.
                (c) 2008 Wiley-Liss, Inc. The RMS4.99 study was designed to explore the role of multiple sequential high-dose chemotherapy cycles administered early in the treatment of children with metastatic rhabdomyosarcoma.
                Seventy patients were enrolled and received three cycles of initial standard chemotherapy, followed by a course of cyclophosphamide and etoposide to obtain peripheral blood stem cells (PBSC), then three consecutive high-dose combinations followed by PBSC rescue. This was followed by surgery and/or radiotherapy, after which a final maintenance treatment with six courses of vincristine, actinomycin D and cyclophosphamide was administered.
                Sixty-two patients underwent the high-dose chemotherapy phase. The 3-year overall survival (OS) and progression free survival (PFS) rates for the 70 patients were 42.3% (95% confidence interval [CI] 39.5-53.6) and 35.3% (95% CI, 24.3-46.5), respectively. By multivariate analysis survival correlated strongly with age > 10 years. In a subset of patients with only one or no unfavourable prognostic factors (age > 10 years, unfavourable site of primary tumour, bone or bone marrow involvement and number of metastatic sites >2) the PFS was significantly higher, i.e. 60.5% at 3 years.
                Our study confirms that patients with favourable prognostic characteristics have a better survival. The use of sequential cycles of high-dose chemotherapy did not appear of benefit for patients with metastatic rhabdomyosarcoma. The European Collaborative MMT4-91 trial was conducted as a prospective nonrandomized study to evaluate the potential benefit of high-dose melphalan as consolidation of first complete remission in children with stage IV rhabdomyosarcoma.
                Fifty-two patients in complete remission after six courses of chemotherapy received "megatherapy": 42 received melphalan alone, whereas 10 received melphalan in combination with etoposide, carboplatin/etoposide, or thiotepa/busulfan and etoposide. The outcome of this group of patients was compared with that observed in 44 patients who were also in complete remission after six courses of identical chemotherapy (plus surgery or radiotherapy) but went on to receive a total of up to 12 courses of conventional chemotherapy (four cycles). No differences were found between the two groups regarding clinical characteristics, chemotherapy received before complete remission, or response to chemotherapy. In particular, there was no significant difference between the groups for site of primary tumor, histologic subtype, age at presentation, presence of bone or bone marrow metastases, or number of metastases.
                The 3-year event-free survival (EFS) and overall survival (OS) rates were 29.7% and 40%, respectively, for those receiving high-dose melphalan or other multiagent high-dose regimens and 19.2% and 27.7%, respectively, for those receiving standard chemotherapy. The difference was not statistically significant (P =.3 and P =.2 for EFS and OS, respectively). There was a significant prolongation in the time from the last day of high-dose chemotherapy or the end of chemotherapy cycle 4 to the time of relapse in those receiving megatherapy (168 days for patients receiving megatherapy v 104 days for those receiving standard therapy; P =.05).
                The addition of a high-dose alkylating agent to consolidation therapy may have prolonged progression-free survival in this poor-risk patient group, but it did not significantly improve the ultimate outcome.
Overall, the results of this review do not justify the use of HDC with SCR as a standard therapy for children with metastatic rhabdomyosarcoma. However, all reported studies were possibly subject to significant bias, especially selection bias. This might have underestimated the measured effect of HDC. As a result, a clinically important excess of adverse risk patients in the HDC arms may explain the non-beneficial effect of HDC. Only a large prospective RCT will be able to answer the question of whether HDC with SCR adds to survival or not definitively.