Soft Tissue Sarcomas in Children

Pediatric soft tissue sarcomas (STS) are a heterogeneous group of malignant tumors constituting about 7% of all cancer cases. Rhabdomyosarcomas (RMS) constitute about half of all soft tissue sarcomas in children, the rest being constituted by non- rhabdomyosarcoma soft tissue sarcomas (NRSTS). Most RMS present in young children <6 y of age while the NRSTS occur in adolescents and young adults. The latter constitute a diverse group of tumors and are rare in children. The STS generally present as painless enlarging mass or with symptoms of compression/infiltration of adjacent organs or structures. Staging, risk stratification and multidisciplinary approach are needed for the treatment of STS and outcome depends on stage, site and histological type. Treatment of RMS has evolved systematically through various clinical trials. Chemotherapy remains the backbone of treatment for RMS and local control is achieved either with surgery or radiotherapy or both. Management of NRSTS is still a challenge as it is generally chemotherapy-resistant and surgery remains the mainstay of treatment. Outcome therefore depends on whether wide local excision with negative margins is possible. Local radiotherapy is reserved for recurrent, residual and large high grade NRST. The prognosis of metastatic as well as recurrent STS remains dismal.     

Children's Oncology Group's 2013 blueprint for research: Soft tissue sarcomas

In the US, approximately 850–900 children are diagnosed each year with soft tissue sarcomas (STS). Key findings from recent Children's Oncology Group (COG) clinical trials include safe reduction in therapy for low risk rhabdomyosarcoma (RMS), validation of FOXO1 fusion as a prognostic factor, a modest improvement in outcome for high‐risk RMS, and a biologically designed non‐cytotoxic therapy for pediatric desmoid tumor. Planned Phase 2 trials include targeted agents for VEGF/PDGF, mTOR, and IGF‐1R for children with RMS and VEGF for children with non‐RMS STS (NRSTS). For RMS, COG Phase 3 trials potentially will explore VEGF/mTOR inhibition or chemotherapy interval compression. For NRSTS, a COG Phase 3 trial will explore VEGF inhibition. Pediatr Blood Cancer 2013; 60: 1001–1008. © 2012 Wiley Periodicals, Inc.     

Soft-tissue sarcomas other than rhabdomyosarcoma in children.

Forty-seven children with nonrhabdomyosarcomatous soft-tissue sarcomas (NRSTS) were treated by the Hematology-Oncology Service at Texas Children's Hospital, Houston, Texas, between 1958 and 1990. The male:female ratio was 1:1, and the median age was 11 years (3 weeks-16 years). A preexisting condition was found in 9/47 (19%) patients including neurofibromatosis (3), Down's syndrome (1), spina bifida (1), congenital facial asymmetry (1), giant pigmented nevus (1), juvenile onset diabetes mellitus (1), and acquired immune deficiency syndrome (1). The site of primary tumor was head and neck (3), trunk (33), and extremities (11). Twenty-four patients (51%) have survived free of disease with a median follow-up of 5 years (4 months-22 years). No patient whose disease recurred achieved a second remission. Of the 19 patients with group I disease, 16 (84%) survived free of disease. Wide excision of the primary tumor, with no microscopic residual disease, was associated with the greatest chance of disease-free survival.     

Soft-tissue sarcomas other than rhabdomyosarcoma in children

Forty-seven children with nonrhabdomyosarcomatous soft-tissue sarcomas (NRSTS) were treated by the Hematology-Oncology Service at Texas Children's Hospital, Houston, Texas, between 1958 and 1990. The male: female ratio was 1:1, and the median age was 11 years (3 weeks-16 years). A preexisting condition was found in 9/47 (19%) patients including neurofibromatosis (3), Down's syndrome (1), spina bifida (1), congenital facial asymmetry (1), giant pigmented nevus (1), juvenile onset diabetes mellitus (1), and acquired immune deficiency syndrome (1). The site of primary tumor was head and neck (3), trunk (33), and extremities (11). Twenty-four patients (51%) have survived free of disease with a median follow-up of 5 years (4 months-22 years). No patient whose disease recurred achieved a second remission. Of the 19 patients with group I disease, 16 (84%) survived free of disease. Wide excision of the primary tumor, with no microscopic residual disease, was associated with the greatest chance of disease-freesurvival.     

Metastatic nonrhabdomyosarcomatous soft-tissue sarcomas in children and adolescents: the St. Jude Children's Research Hospital experience.

BACKGROUND: Because the natural history of pediatric patients with metastatic nonrhabdomyosarcomatous soft-tissue sarcomas (NRSTS) had not been well described, we retrospectively reviewed our single-institution experience with these tumors. PROCEDURE: We identified 26 patients with metastatic NRSTS who were treated at St. Jude Children's Research Hospital from December 1971 through July 1995. We evaluated the characteristics of each patient, including age, sex, primary site, stage, type of therapy received, and outcome. Sites of metastatic disease at diagnosis and relapse were noted. RESULTS: The median age of the 26 study patients at diagnosis was 14. 8 years; 54% of patients were male and 69% were white. The most common histologies were synovial sarcoma, alveolar soft-part sarcoma, and malignant fibrous histiocytoma. Most primary tumors (73% of cases) occurred in the trunk or extremities. Most patients presented with large (>5 cm), high-grade lesions. All 26 patients received chemotherapy, and 8 responded to an ifosfamide- or cyclophosphamide-doxorubicin-based regimen. Radiotherapy was administered to 15 patients, and 13 had a partial or complete resection of the primary tumor. Six patients underwent thoracotomy. The estimated 2-year survival for the cohort was 34.6% +/- 8.9%; the 2-year progression-free survival was 15.4% +/- 6.3%. The lung was the most common site of failure. CONCLUSIONS: Children with metastatic NRSTS have a poor outcome, which is similar to that in adults. More effective systemic chemotherapy is needed to facilitate complete surgical resection of primary and metastatic sites. Aggressive pulmonary metastatectomy can increase disease control.     

儿童非横纹肌软组织肉瘤临床预后因素及治疗对策

目的 分析18岁以下儿童和青少年的非横纹肌肉瘤的生存率,并探讨常见肿瘤的治疗策略。方法 对1989年1月到2002年12月治疗并随访的67例非横纹肌肉瘤病例的资料进行分析,其中滑膜肉瘤16例,恶性纤维组织细胞瘤9例,纤维肉瘤9例,脂肪肉瘤7例,骨外尤文氏肉瘤/原始神经外胚叶瘤7例,腺泡状软组织肉瘤6例,平滑肌肉瘤4例,恶性外周神经鞘瘤、透明细胞软组织肉瘤、血管肉瘤各2例,上皮性软组织肉瘤、促纤维增生性小圆细胞肿瘤、恶性肾外横纹肌样肿瘤各1例。引入年龄、性别、肿瘤大小、外科病理分期、是否接受化疗和放疗等因素,应用SPSS10.0统计软件,采用COX回归和χ^2检验进行统计学分析。结果 影响非横纹肌肉瘤生存率的唯一临床因素是外科病理分期。手术完全切除比肿瘤残留或转移者的生存率更高,Ⅰ、Ⅱ期和Ⅲ、Ⅳ期的2年EFS分别为89.74%和17.86%,差异有统计学意义。无肿瘤残留者生存率高于肿瘤残留或不能切除者。结论 儿童和青少年非横纹肌软组织肉瘤罕见,各肿瘤的临床特征不同,尚无统一治疗方法。治疗原则仍以达到无肿瘤残留为目标的外科手术治疗为主;除尤文氏瘤/原始神经外胚叶瘤和滑膜肉瘤已经证实化疗有效外,其他肿瘤的术后辅助化疗和放疗尚存在争议。新辅助化疗对于部分不能切除的肿瘤可以提高手术切除率。成立全国性的协作组可以尽快积累病例,增加治疗经验,制定规范的治疗方案,是改善儿童非横纹肌软组织肉瘤疗效的有效途径。     

THE ROLE OF CHEMOTHERAPY IN CHILDHOOD SOFT TISSUE SARCOMAS OTHER THAN RHABDOMYOSARCOMAS: Experience of the Northern Israel Oncology Center

Forty-three children with nonrhabdomyosarcomatous soft tissue sarcomas (NRSTS) were treated at the Northern Israel Oncology Center in Haifa, Israel, from 1971 to 1996. The male:female ratio was 1.5:1 and the median age of patient was 10 years (range, 3 months-18 years). The most common histopathologic diagnoses were fibrosarcoma (32.5%) and synovial sarcoma (16%). The sites of primary tumor were lower limb (35%), trunk (18%), upper limb (16%), head and neck (16%), and retroperitoneum (11%). By Intergroup Rhabdomyosarcoma Study classifications, 13 patients presented as group I, 15 patients as group II, 10 patients as group III, and 5 patients as group IV. Median follow-up time was 63 months (range, 6 months-18 years). The estimated survival after a 5-year period is 72% (SE 17) for patients in group I, 75 15% in group II, 90 9% for patients in group III, and 40 21% for patients in group IV. Eleven patients relapsed; 4/6 who developed local relapse were cured and are alive with disease, while 4/5 who developed distant metastases are dead. For the 28 patients who underwent complete resection at diagnosis, the estimated survival after a 5-year period is 87 5% vs. 60 17% for the 15 patients who underwent partial excision or biopsy. Local radiotherapy was delivered after surgery to group III patients. Preoperative and postoperative chemotherapy was delivered to the patients of groups III and IV, and postoperative chemotherapy only to group II patients. Chemotherapy produced demonstrable gain in survival for group II and III patients but not for patients with metastases. The authors conclude that an aggressive surgical approach is needed in patients with NRSTS. Chemotherapy may help as a preoperative treatment in bulky disease or as a postoperative treatment for microscopic residual disease.     

THE ROLE OF CHEMOTHERAPY IN CHILDHOOD SOFT TISSUE SARCOMAS OTHER THAN RHABDOMYOSARCOMAS: Experience of the Northern Israel Oncology Center

Forty-three children with nonrhabdomyosarcomatous soft tissue sarcomas (NRSTS) were treated at the Northern Israel Oncology Center in Haifa, Israel, from 1971 to 1996. The male:female ratio was 1.5:1 and the median age of patient was 10 years (range, 3 months-18 years). The most common histopathologic diagnoses were fibrosarcoma (32.5%) and synovial sarcoma (16%). The sites of primary tumor were lower limb (35%), trunk (18%), upper limb (16%), head and neck (16%), and retroperitoneum (11%). By Intergroup Rhabdomyosarcoma Study classifications, 13 patients presented as group I, 15 patients as group II, 10 patients as group III, and 5 patients as group IV. Median follow-up time was 63 months (range, 6 months-18 years). The estimated survival after a 5-year period is 72% (SE 17) for patients in group I, 75 15% in group II, 90 9% for patients in group III, and 40 21% for patients in group IV. Eleven patients relapsed; 4/6 who developed local relapse were cured and are alive with disease, while 4/5 who developed distant metastases are dead. For the 28 patients who underwent complete resection at diagnosis, the estimated survival after a 5-year period is 87 5% vs. 60 17% for the 15 patients who underwent partial excision or biopsy. Local radiotherapy was delivered after surgery to group III patients. Preoperative and postoperative chemotherapy was delivered to the patients of groups III and IV, and postoperative chemotherapy only to group II patients. Chemotherapy produced demonstrable gain in survival for group II and III patients but not for patients with metastases. The authors conclude that an aggressive surgical approach is needed in patients with NRSTS. Chemotherapy may help as a preoperative treatment in bulky disease or as a postoperative treatment for microscopic residual disease.     

Adjuvant chemotherapy for the treatment of advanced pediatric nonrhabdomyosarcoma soft tissue sarcoma: the National Cancer Institute experience

BACKGROUND: The survival of children and adolescents with advanced (unresectable or metastatic) nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) is poor. In order to clarify the role of combining chemotherapy with aggressive local control using surgery and/or radiation, we reviewed our institutional experience with the treatment of advanced pediatric NRSTS. PROCEDURE: We reviewed the charts of all patients less than 21 years treated for an advanced NRSTS at the National Cancer Institute (NCI) between 1983 and 2003. Tumor pathology was confirmed and demographic, disease, and treatment data were abstracted. Survival was calculated using standard methods. RESULTS: Of the 25 patients who were treated over the study period, 15 had metastatic disease and 10 had unresectable or incompletely resected disease at presentation. Twenty-one patients received chemotherapy consisting of the combination of vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide, and the remaining 4 received regimens that included doxorubicin. Twenty patients (80%) had a complete (5/25) or partial (15/25) response after chemotherapy alone. After the combination of chemotherapy and local control, 14 patients (56%) had a complete response (CR). The estimated 5-year overall and event-free survival (EFS) for all patients was 0.50 (standard error = 0.11) and 0.34 (standard error = 0.10), respectively. CONCLUSIONS: The combination of chemotherapy with aggressive local control in this cohort of pediatric patients with advanced NRSTS yielded results comparable to those observed in patients with advanced sarcomas that are chemotherapy responsive. Prospective randomized trials are needed to quantify the contribution of chemotherapy and to determine the ideal regimen.     

Recent advances in non-rhabdomyosarcoma soft-tissue sarcomas

Nonrhabdomyosarcoma soft-tissue sarcomas (NRSTS) represent a subgroup of sarcomas that encompass more than 50 distinct histologies. All are rare, but some are more common in patients younger than 20 years of age. The management of patients with many histologies overlap. However, this review will focus on issues unique to a select few NRSTS that are most common in pediatric and adolescent patients. Here, we will discuss the recent advances in the diagnosis, surgical management, and treatment of NRSTS. Adequate surgical local control of the primary tumor is a critical component of the treatment strategy will be emphasized in this review because it determines local and distant recurrence.     

Radiation therapy for non-rhabdomyosarcoma soft tissue sarcomas in adolescents and young adults

Non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) are less responsive to radiotherapy than the more common pediatric soft tissue sarcomas, rhabdomyosarcoma and Ewing sarcoma of soft tissue. However, radiation therapy does play an important role in the treatment of NRSTS, including synovial sarcoma. Little data exists regarding the behavior or treatment of these tumors in adolescents and young adults compared to older populations. Limb-preservation with adjuvant radiation thereby is standard. There is a greater incentive to reduce long-term complications of radiation in younger patients and thus smaller margins, lower doses, and conformal techniques should be considered. Results of anticipated cooperative group studies promise to guide future therapy for the various types of NRSTS.     

Results of treatment of rhabdomyosarcomas (RMS) in children. A report of the Cooperative Soft Tissue Sarcoma Study (CWS-81) of the Society of Pediatric Oncology

This analysis refers to 129 children with RMS who were treated between 1981 and 1985 according to the protocol guidelines of the CWS-81 study. The duration of chemotherapy depended on the initial post-operative stage. Patients with stage I and IIA were not to receive any radiotherapy, and patients with primary stage III were treated according to the results of a 16-week chemotherapy treatment: either without radiation (stage Ipc), or with radiotherapy using 40 Gy (stage (IIpc) or 50 Gy (stage IIIpc). The median time of observation was 27 months (Juni 1985). The essential results of the study are as follow: RMS of the extremities in stages I and IIA need radiotherapy, contrary to all other localisations with the same stages. Patients with RMS stage III who are tumor-free after initial chemotherapy (histologically checked) do not need radiotherapy. Patients with microscopic residue (IIpc) or macroscopic residue (IIIpc) after pretreatment showed no difference in their local relapse rate, whereas metastases were found only in the group having macroscopic tumor residue up to week 16. An additional examination of this study observed tumor response during initial chemotherapy and its relationship to prognosis. This analysis showed that the degree of tumor regression per unit of time permits the most favorable prognostic statement. Patients with clinical complete remission after 7/9 weeks showed a 100% relapse-free chance of survival, independent of localisation, tumor size or histological subtype. Those with a tumor reduction of greater than 2/3 but no complete remission showed 67% chance of survival, and those with greater than 1/3-2/3 tumor reduction had 25%. Tumor response kinetics under initial chemotherapy allows better individual therapy in the future. The overall result of the study concerning localisation and stage corresponds to that of the IRS I and II studies. Patients with undifferentiated sarcomas, extraossary Ewing's sarcoma and synovial sarcomas can be treated according to the same principles as RMS, since no significant differences in prognosis could be found.     

p53 and mdm-2 Expression in Rhabdomyosarcoma of Childhood and Adolescence: Clinicopathologic Study by the Kiel Pediatric Tumor Registry and the German Cooperative Soft Tissue Sarcoma Study

Rhabdomyosarcomas (RMS) are the most common malignant soft tissue sarcomas in childhood and adolescence. Despite a large number of publications about this heterogeneous group of tumors, little is known about proliferation, p53 and mdm-2 in relation to histological subtype, clinical parameter, and prognosis of patients. We studied 150 cases of RMS treated in the German Cooperative Soft Tissue Sarcoma Study (CWS) by immunohistochemistry on paraffin-embedded tissue, using antibodies against p53, mdm-2, and Ki-67. The results were correlated with histological subtype, mitotic count, and various clinical parameters. Both p53 and mdm-2 were expressed at low levels and did not show differences between embryonal and alveolar RMS. Tumors of patients with metastatic embryonal RMS showed significantly higher levels of p53 protein than nonmetastatic tumors. This might be a clue to an important role of p53 in metastatic embryonal RMS. Nevertheless, neither p53 nor mdm-2 showed any correlation to prognosis. Proliferation measured by Ki-67 immunostaining (KiS5 antibody) or mitotic count did not show significant differences between embryonal and alveolar RMS. In addition, these parameters did not correlate with response to therapy or prognosis. In conclusion, we could not demonstrate that any of the investigated parameters had an influence on prognosis of RMS. p53 protein overexpression might be a crucial step in metastatic disease for patients with embryonal RMS.     

The role of adjuvant chemotherapy in children and adolescents with surgically resected, high-risk adult-type soft tissue sarcomas

PURPOSE: This analysis evaluates whether adjuvant chemotherapy can be recommended for high-risk, surgically-resected, adult-type non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) within the new European Pediatric Soft Tissue Sarcoma Study Group (EpSSG) protocol. The Italian and German Cooperative Groups reviewed their data-bases, analyzing patients classified as group I-II, with high-grade tumor (G3) larger than 5 cm in size. METHODS: The analysis included 36 patients, and compared the clinical features and outcome of the group of 21 patients who received chemotherapy versus the group of 15 patients treated with local therapies only. RESULTS: For the series as a whole, 5-year event-free survival (EFS), metastasis-free survival (MFS), and overall survival (OS) were 26.2%, 34.0%, and 37.5%, respectively. In patients treated with chemotherapy, MFS and OS were 49.5% and 41.5% (median time to relapse: 13 months). In patients who did not receive chemotherapy, MFS and OS were 0% and 23.8% (median time to relapse: 3 months). CONCLUSION: The role of adjuvant chemotherapy in NRSTS is still uncertain, however, the current retrospective analysis showed that: (1) despite the globally good prognosis of grossly-resected cases, patients with G3 and large-size have a high-risk of metastatic spread, and (2) MFS appears to be better in patients who had chemotherapy. Based in part on these results, and in accordance with recent suggestions coming from the literature on adult sarcomas, the EpSSG NRSTS protocol will recommend adjuvant chemotherapy in high-risk surgically-resected patients.     

Topotecan by 21-day continuous infusion in children with relapsed or refractory solid tumors: a Children's Oncology Group study

PURPOSE: The Children's Oncology Group conducted a phase II trial of 21-day continuous infusion topotecan to determine the response rate in pediatric patients with recurrent or refractory malignant solid tumors. PROCEDURE: Patients with Ewing sarcoma family of tumors (ESFT), osteosarcoma (OS), soft tissue sarcomas (STS), medulloblastoma (MB)/primitive neuroectodermal tumor (PNET), astrocytoma, or neuroblastoma (NB) recurrent or refractory to conventional therapy, measurable disease, and adequate organ function were treated with topotecan 0.3 mg/m2/day by continuous intravenous infusion for 21 consecutive days, followed by 7 days without therapy prior to response assessment. RESULTS: Fifty-five patients were enrolled; two were ineligible, two were removed from protocol therapy prior to evaluation for response, and one was inevaluable for response, leaving 53 and 50 patients evaluable for toxicity and response, respectively. Objective responses were seen in 2/20 patients with ESFT (both partial responses, 4 and 19 courses), 0/10 OS patients, and 0/12 STS patients. There were insufficient patients enrolled to determine the response rate for the MB/PNET, astrocytoma, and NB strata. The most common Grade 3 or 4 toxicities during the first course of therapy were thrombocytopenia (12/53), neutropenia (8/53), and fatigue (7/53). CONCLUSION: Intravenous topotecan by 21-day continuous infusion is tolerable in pediatric patients with recurrent or refractory solid tumors. Limited activity was seen in ESFT and further development of this topotecan schedule as a single agent is not warranted.     

Metastatic rhabdomyosarcoma and histologically similar tumors in childhood: A retrospective european multi-center analysis

This is a retrospective analysis of children with metastatic soft tissue sarcoma (STS) registered in the major European STS studies: the SIOP MMT 75, the German CWS 1981 and 1986 studies, the Italian STS study, and the United Kingdom Children's Cancer Study Group centres in Britain. One hundred forty-six patients out of 164 were evaluable in this analysis. The median age was 7 years (1–18) and the male/female ratio was 1.3:1. The median follow-up was 80 months (7–171). The most common site of the primary tumor was the extremity (28%), which correlated well with the high preponderance (39%) of the alveolar type of RMS (aRMS). There was no dominant combination of metastatic sites and the most common single organ with metastasis was the lung (41%). Since the therapy depended on the country and period in which the patient was treated, we did not analyse the outcome and therapy together. Complete remission was achieved in 50% of the cases. Those with aRMS had a good chance of achieving CR (61%) but the majority of these patients relapsed (78%). The median time needed to relapse was 243 days (53 days to 47 months) for all patients. Analysis of the site of the primary tumor showed that the CR rate was best in the GU non-BP site (62%) and worst in PM cases (35%). The overall survival and DFS rate were 18% and 15%, respectively. The GU non-BP patients had a DFS rate of 50%, while the rate for all other sites varied between 12% and 18%. A total of 24 patients remained in CCR. The majority of them had embryonal type of RMS and metastases in only one anatomic site. Our analysis indicates that the best chance of prolonged survival was in metastatic GU non-BP cases, patients with embryonal type RMS, and those with metastases in only one organ. To try to improve the treatment of metastatic STS, a prospective European cooperative study was started in 1989. © 1992 Wiley-Liss, Inc.     

Therapeutic difficulties in soft tissue sarcoma occurring in children with neurofibromatosis type 1 - own observations

Neurofibromatosis type I (NF1) is one of the most common genetic disorders in man, predisposing to benign and malignant tumours. The most common malignancies comprise nervous system tumours, less frequently soft tissue sarcomas (STS) and leukaemia - myelodysplasia syndrome. Herein we report five cases of STS diagnosed in children affected with NF1 (3 girls and 2 boys, age: 8 months -17 years). Neurogenic tumours were diagnosed in three children (malignant peripheral nerve-sheath tumour in two and malignant triton tumour in one), while soft tissue sarcomas of rhabdomyosarcoma origin were found in two patients. In four cases the primary tumours were highly locally advanced, unresectable and located in pelvis minor. All patients received protocols for soft STS: CWS-91, 96 and 2002. The paper presents the clinical symptomatology, the course and outcome in children with NF1 affected with STS. CONCLUSION: basing on our own observations STS in NF1 seems to have poor prognosis in spite of combined therapy. Since early diagnosis is essential, children with NF1 should remain under the care of the oncologist.     

Very intensive, short-term chemotherapy for children and adolescents with metastatic sarcomas

BACKGROUND: To improve the prognosis for pediatric patients with metastatic sarcomas, including the Ewing sarcoma family of tumors (ESFT), rhabdomyosarcoma (RMS), and undifferentiated sarcoma (UDS), we tested the feasibility of a brief, intensive regimen of chemotherapy that maximizes dose intensity. PROCEDURE: Twenty-four children and adolescents with metastatic sarcomas received VACIME chemotherapy, consisting of eight courses of vincristine 2 mg/m(2) on day 0; doxorubicin 20 mg/m(2)/day on days 0-3; cyclophosphamide 360 mg/m(2)/day on days 0-4; ifosfamide 1,800 mg/m(2)/day on days 0-4; mesna 2,400 mg/m(2)/day; and etoposide 100 mg/m(2)/day on days 0-4. Doxorubicin was omitted in courses 7 and 8. Granulocyte colony-stimulating factor (G-CSF) was used routinely following each course of therapy. Courses of therapy were repeated every 21 days or as soon as hematopoietic recovery and resolution of nonhematopoietic toxicities permitted. Surgical resection followed course 6, and radiotherapy followed the completion of all therapy. RESULTS: Thirteen patients achieved a complete response (CR) with chemotherapy alone, and seven more achieved a CR following surgical resection after course 6 (overall CR rate 83%). There was one toxic death. Thirteen patients developed progressive disease, with 2- and 4-year event-free survivals (95% confidence interval) of 50% (30-70%) and 45% (25-65%), respectively. Myelosuppression was severe and cumulative, leading to dose reductions and chemotherapy interval delays. Mucositis was the most common nonhematopoietic toxicity. CONCLUSIONS: VACIME chemotherapy was a feasible dose-intensive regimen for pediatric patients with metastatic sarcomas. Cumulative hematopoietic toxicity and severe mucositis limited the delivery of chemotherapy as prescribed. The CR and 2-year event-free survival rates were superior to those of most previously reported regimens.