Successful clinical response to irinotecan in desmoplastic round blue cell tumor

Trabectedin-irinotecan, a potentially promising combination in relapsed desmoplastic small round cell tumor: report of two cases

Effective new drugs are urgently needed for desmoplastic small round cell tumor (DSRCT), an extremely rare and aggressive disease with a generally poor prognosis. We describe two heavily-pretreated young patients with advanced-stage DSRCT given third-line treatment with a combination of trabectedin and irinotecan, based on our preclinical data demonstrating its effect on patient-derived xenografts. This trabectedin-irinotecan treatment showed a limited toxicity. One patient had a mixed response (overall stable disease), the other a complete tumor remission. This is the first report of preliminary findings to suggest that combining trabectedin and irinotecan is worth further investigating as a potentially valuable chemotherapy for DSRCT.

Intraabdominal and ganglionic desmoplastic small round cell tumor: a case series

Introduction

Desmoplastic small round cell tumor is a rare malignancy with poor prognosis, affecting young male patients. It frequently presents as a large abdominal mass with widespread peritoneal involvement at diagnosis. In late stages, metastases may be present.

Aim

We retrospectively reviewed patient characteristics, presenting symptoms, tumor pathology, treatment, and outcome of four patients with desmoplastic small round cell tumor at our institution.

Cases presentation

The first three cases reported are 32-, 17-, and 30-year-old North African males with intraabdominal desmoplastic small round cell tumor treated by surgery, chemotherapy, and radiation therapy with different follow-ups. The final case is a 16-year-old North African male with ganglionic desmoplastic small round cell tumor but no evidence of a tissue mass. He underwent two lines of chemotherapy with no response. The patient was lost after 2 years of follow-up. In all cases, desmoplastic small round cell tumor was confirmed by presence of t(11,22) (p13,q12) translocation.

Conclusion

Treatment of desmoplastic small round cell tumor is based on multidisciplinary therapy. Despite high-dose chemotherapy, extensive surgical resection, and radiotherapy, desmoplastic small round cell tumor remains lethal.

Multiagent chemotherapy including IrIVA regimen and maintenance therapy in the treatment of desmoplastic small round cell tumor

This study reports the treatment feasibility and efficacy of a novel multiagent intensive treatment program for young patients with desmoplastic small round cell tumor. This small series includes three patients and should be seen as a first suggestion of integration of the dose density and the maintenance chemotherapy concept. The IrIVA regimen (irinotecan, ifosfamide, vincristine, and actinomycin-D) is added-used at a short interval between chemotherapy administrations-at more classic intensive ifosfamide-based regimens. The vinorelbine and low-dose oral cyclophosphamide maintenance therapy is added at the end of conventional chemotherapy to achieve an antiangiogenic effect.

Therapeutic Potential of NTRK3 Inhibition in Desmoplastic Small Round Cell Tumor

PURPOSE

Desmoplastic small round cell tumor (DSRCT) is a highly lethal intra-abdominal sarcoma of adolescents and young adults. DSRCT harbors a t(11;22)(p13:q12) that generates the EWSR1-WT1 chimeric transcription factor, the key oncogenic driver of DSRCT. EWSR1-WT1 rewires global gene expression networks and activates aberrant expression of targets that together mediate oncogenesis. EWSR1-WT1 also activates a neural gene expression program.

EXPERIMENTAL DESIGN

Among these neural markers, we found prominent expression of neurotrophic tyrosine kinase receptor 3 (NTRK3), a druggable receptor tyrosine kinase. We investigated the regulation of NTRK3 by EWSR1-WT1 and its potential as a therapeutic target in vitro and in vivo, the latter using novel patient-derived models of DSRCT.

RESULTS

We found that EWSR1-WT1 binds upstream of NTRK3 and activates its transcription. NTRK3 mRNA is highly expressed in DSRCT compared with other major chimeric transcription factor-driven sarcomas and most DSRCTs are strongly immunoreactive for NTRK3 protein. Remarkably, expression of NTRK3 kinase domain mRNA in DSRCT is also higher than in cancers with NTRK3 fusions. Abrogation of NTRK3 expression by RNAi silencing reduces growth of DSRCT cells and pharmacologic targeting of NTRK3 with entrectinib is effective in both in vitro and in vivo models of DSRCT.

CONCLUSIONS

Our results indicate that EWSR1-WT1 directly activates NTRK3 expression in DSRCT cells, which are dependent on its expression and activity for growth. Pharmacologic inhibition of NTRK3 by entrectinib significantly reduces growth of DSRCT cells both in vitro and in vivo, providing a rationale for clinical evaluation of NTRK3 as a therapeutic target in DSRCT.

The use of interval-compressed chemotherapy with the addition of vincristine, irinotecan, and temozolomide for pediatric patients with newly diagnosed desmoplastic small round cell tumor

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a rare aggressive sarcoma that affects children and young adults, and portends poor outcomes despite intensive multimodal treatment approaches. We report toxicity, response, and outcomes of patients with DSRCT treated with the addition of vincristine, irinotecan, and temozolomide (VIT) to interval-compressed chemotherapy as per Children's Oncology Group ARST08P1.

METHODS

All newly diagnosed pediatric patients with DSRCT treated at Dana-Farber Cancer Institute and Boston Children's Hospital between 2014 and 2019 as per ARST08P1, Arm P2 with replacement of VAC cycles with VIT, were identified. Medical records were reviewed for clinical and disease characteristics, and treatment response and outcomes.

RESULTS

Six patients were treated as per the above regimen. Median age at diagnosis was 15.1 years (range 3.2-16.4) and five patients were male. Five patients had abdominal primary tumors, of which one had exclusively intraabdominal and four had extraabdominal metastases. Two initial cycles of VIT were well tolerated with nausea, vomiting, diarrhea, and constipation as the most common adverse events. Overall response rate defined as partial or complete response after two initial cycles of VIT was 50%. For local control, all patients had surgical resection followed by radiotherapy, and two patients received hyperthermic intraperitoneal chemotherapy at the time of surgery. Of the four patients who have completed therapy to date, three remain disease-free with median follow-up time of 46.7 months.

CONCLUSIONS

The addition of VIT to interval-compressed chemotherapy is tolerable and active in DSRCT, with activity warranting additional investigation.

Irinotecan and vincristine for the treatment of refractory desmoplastic small round cell tumor in a developing country: a case report

Introduction

Desmoplastic small round cell tumor is an extremely rare and aggressive cancer that affects mainly adolescents and young adults. Despite multiple therapeutic strategies, most patients have resistant disease with very poor survival rates.

Case presentation

We present a case of a 10-year-old Caucasian boy with a desmoplastic small round cell tumor refractory to conventional treatment who exhibited a good response to alternative treatment. With use of irinotecan and vincristine in association with radiation therapy, a reduction of 96.9% of the dimensions of the target lesions compared with the initial image was observed.

Conclusion

This chemotherapy regimen, in association with radiation therapy, demonstrated efficacy for refractory desmoplastic small round cell tumor in our patient, and it is cost-effective.

Desmoplastic small round cell tumors: Multimodality treatment and new risk factors

Background

To evaluate optimal therapy and potential risk factors.

Methods

Data of DSRCT patients <40 years treated in prospective CWS trials 1997‐2015 were analyzed.

Results

Median age of 60 patients was 14.5 years. Male:female ratio was 4:1. Tumors were abdominal/retroperitoneal in 56/60 (93%). 6/60 (10%) presented with a localized mass, 16/60 (27%) regionally disseminated nodes, and 38/60 (63%) with extraperitoneal metastases. At diagnosis, 23/60 (38%) patients had effusions, 4/60 (7%) a thrombosis, and 37/54 (69%) elevated CRP. 40/60 (67%) patients underwent tumor resection, 21/60 (35%) macroscopically complete. 37/60 (62%) received chemotherapy according to CEVAIE (ifosfamide, vincristine, actinomycin D, carboplatin, epirubicin, etoposide), 15/60 (25%) VAIA (ifosfamide, vincristine, adriamycin, actinomycin D) and, 5/60 (8%) P6 (cyclophosphamide, doxorubicin, vincristine, ifosfamide, etoposide). Nine received high‐dose chemotherapy, 6 received regional hyperthermia, and 20 received radiotherapy. Among 25 patients achieving complete remission, 18 (72%) received metronomic therapies. Three‐year event‐free (EFS) and overall survival (OS) were 11% (±8 confidence interval [CI] 95%) and 30% (±12 CI 95%), respectively, for all patients and 26.7% (±18.0 CI 95%) and 56.9% (±20.4 CI 95%) for 25 patients achieving remission. Extra‐abdominal site, localized disease, no effusion or ascites only, absence of thrombosis, normal CRP, complete tumor resection, and chemotherapy with VAIA correlated with EFS in univariate analysis. In multivariate analysis, significant factors were no thrombosis and chemotherapy with VAIA. In patients achieving complete remission, metronomic therapy with cyclophosphamide/vinblastine correlated with prolonged time to relapse.

Conclusion

Pleural effusions, venous thrombosis, and CRP elevation were identified as potential risk factors. The VAIA scheme showed best outcome. Maintenance therapy should be investigated further.

Desmoplastic Small Round Cell Tumor

Desmoplastic small round cell tumor (DSRCT) is an aggressive small round cell neoplasm which predominantly occurs intra-abdominally in adolescents and young adults with a male predominance, and which is characterized by a recurrent t(11;22)(p13;q12) translocation leading to formation of the EWSR1-WT1 fusion gene, which generates a chimeric protein with transcriptional regulatory activity. Histologically, DSRCT has a characteristic morphology, of islands of monotonous small cells within prominent sparsely cellular fibroblastic stroma, and immunohistochemically it shows polyphenotypic multidirectional differentiation, with expression of epithelial, muscle, and neural markers. However, DSRCT can arise more rarely in other sites and exhibit a spectrum of both histologic features and immunoprofile, which may confuse diagnosis with other small round cell neoplasms. Correct diagnosis is important to ensure correct treatment and prognostication; DSRCT are almost universally fatal neoplasms with patients usually succumbing to disease within the first 2 years of diagnosis. While combination treatment strategies can confer a survival benefit, the overall prognosis remains poor. Further insight into the tumorigenic molecular changes generated by the fusion oncogene may lead to the generation of specific targeted therapies. We review DSRCT, discussing morphology and immunohistochemistry, molecular genetic findings, potential targeted treatments, and the differential diagnosis.

Desmoplastic small round cell tumor 20 years after its discovery

Desmoplastic small round cell tumor (DSRCT) was proposed as a distinct disease entity by William L Gerald and Juan Rosai in 1991. Over 850 patients have been reported in the medical literature. A specific translocation, t(11;22)(p13;q12), is seen in almost all cases, juxtaposing the EWS gene to the WT1 tumor suppressor gene. DSRCT is composed of nests of small round cells with polyphenotypic differentiation, typically a mixture of epithelial, mesenchymal and neural features, surrounded by a prominent desmoplastic stroma. DSRCT has a predilection for adolescent and young adult males, and primarily involves the abdominal cavity and pelvis. Survival is low despite their initial response to multimodal treatment. Most patients relapse with disseminated disease that is unresponsive to further therapy.

FDG PET/CT imaging of desmoplastic small round cell tumor: findings at staging, during treatment and at follow-up

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a very uncommon soft-tissue tumor of children and young adults. It has an aggressive course with generally poor survival. In general the assessment of tumor burden and response has relied upon CT or MRI. However these tumors are often metabolically active and can be evaluated using FDG PET/CT imaging.

OBJECTIVE

The purpose of this study was to determine the metabolic activity of desmoplastic small round cell tumors using FDG PET/CT imaging and the potential utility of FDG PET/CT in this disease.

MATERIALS AND METHODS

Eight patients (seven male, one female; ages 2-20 years, median 11 years) with confirmed DSRCT underwent 82 positron emission tomography/computed tomography (PET/CT) scans. PET/CT was used for initial staging (seven patients, eight scans), monitoring response to therapy (eight patients, 37 scans) and for surveillance of DSRCT recurrence (six patients, 37 scans).

RESULTS

Each scan performed at diagnosis showed abnormally elevated uptake in the primary tumor. Five patients had abdominal pelvic involvement, and two of those also had thoracic disease. Six patients whose scans showed no abnormal sites of uptake at the end of therapy have had progression-free survivals of 2-10 years. One patient whose scan continued to show uptake during treatment died of disease 1.3 years from diagnosis. Another patient with persistent uptake remained in treatment 3 years after initial diagnosis. One surveillance scan identified recurrent disease.

CONCLUSION

FDG PET/CT identified elevated metabolic activity in each patient studied. Despite our small sample size, FDG PET/CT scans appear useful for the management of patients with DSCRT. Patients whose studies become negative during or following treatment may have a prolonged remission.

Myeloablative chemotherapy with autologous stem cell transplant for desmoplastic small round cell tumor

Desmoplastic small round cell tumor (DSRCT), a rare, aggressive neoplasm, has a poor prognosis. In this prospective study, we evaluated the role of myeloablative chemotherapy, followed by autologous stem cell transplant in improving survival in DSRCT. After high-dose induction chemotherapy and surgery, 19 patients with chemoresponsive DSRCT underwent autologous stem cell transplant. Myeloablative chemotherapy consisted of carboplatin (400–700 mg/m²/day for 3 days) + thiotepa (300 mg/m²/day for 3 days) ± topotecan (2 mg/m²/day for 5 days). All patients were engrafted and there was no treatment-related mortality. Seventeen patients received radiotherapy to sites of prior or residual disease at a median of 12 weeks after transplant. Five-year event-free and overall survival were 11 ± 7% and 16 ± 8%, respectively. Two patients survive disease-free 16 and 19 years after transplant (both in complete remission before transplant). 14 patients had progression and died of disease at a median of 18 months following autologous transplant. These data do not justify the use of myeloablative chemotherapy with carboplatin plus thiotepa in patients with DSRCT. Alternative therapies should be considered for this aggressive neoplasm.

Desmoplastic small round cell tumour: characteristics and prognostic factors of 41 patients and review of the literature

Background

Desmoplastic small round cell tumour (DSRCT) is a rare but frequently fatal sarcoma, and many of its characteristics still require further clarification.

Methods

We retrospectively analysed 41 patients treated at or referred to two regional referral centres in the UK between 1991 and 2012. A review of the current literature was also performed.

Results

The median age of presentation was 27 years (range 16 to 45 years), with a male-to-female ratio of 3:1. Ninety percent of patients had disease in the abdomen. The median size of the presenting tumour was 13 cm (range 3.5 to 23 cm), and 80% had metastatic disease at diagnosis, mainly in the liver (33%) and lungs (21%). Time-to-progression (TTP) was 3.9, 2.3 and 1.1 months after first-, second- and third-line chemotherapy, respectively. First-line treatment with VIDE chemotherapy appeared to confer the longest TTP (median 14.6 months). Ifosfamide and doxorubicin resulted in TTP of >3.8 months when used in any-line setting. Eleven patients received targeted agents as part of a clinical trial. After a median follow-up of 14 months, the overall median survival (MS) was 16 months. There was no difference in MS with regards to age, gender, or size of the presenting tumour. Patients with extra-abdominal disease survived longer compared to those with tumours in the abdomen (all still alive vs MS of 15 months; P = 0.0246). Patients with non-metastatic intra-abdominal disease who underwent surgery had an MS of 47 months (16 months for those who did not have surgery; P = 0.0235). Radiotherapy for locoregional control in patients with metastatic intra-abdominal DSRCT was associated with longer survival (MS of 47 vs 14 months; P = 0.0147).

Conclusions

DSRCT is a rare but often fatal disease that mainly affects younger male patients. Those with intra-abdominal DSRCT have a poorer prognosis, although surgical resection for localised disease and radiotherapy in the metastatic setting are associated with improved survival. A patient’s age, gender and size of presenting tumour do not have prognostic significance.

Metastatic desmoplastic small round cell tumor controlled by an anthracycline-based regimen: review of the role of chemotherapy

Desmoplastic small round cell tumors (DSRCT) are rare and aggressive malignant neoplasms that usually occur in young males. They usually present intraabdominally with widespread peritoneal involvement at diagnosis and are sometimes associated with lymphadenopathies and liver metastases. Intraabdominal DSRCT is usually disseminated; no curative outcome has yet been achieved. We report a case of metastatic intraabdominal DSRCT controlled by an anthracycline-based regimen. A literature review of the treatment options, mainly chemotherapy, available for this unusual neoplasm, will be discussed. In patients with unresectable or metastatic disease, symptom control is most important because treatment modalities minimally impact survival. Palliative chemotherapy (mainly monotherapy) is preferable.

Desmoplastic small round cell tumors with EWS-WT1 fusion transcript in children and young adults

BACKGROUND

The presence of the EWS-WT1 gene fusion transcript (GFT) is characteristic of desmoplastic small round cell tumor (DSRCT), a rare and very aggressive disease for which the treatment has not yet been clearly standardized.

METHODS

This was a retrospective national multicenter analysis of young patients <30 years with tumors expressing the EWS-WT1-GFT, designed to determine whether extensive surgery had an impact on survival.

RESULTS

Between 1995 and 2006, a EWS-WT1-GFT was detected in the tumors of 38 patients, 17 (44.7%) of whom had had a different initial pathologic diagnosis prior to molecular testing. Mean age was 13.2 years (range: 4-29.7 years). Only 9 patients (24%) had localized disease. Treatment was heterogeneous. Nine patients had "limited" surgical resections and 22 underwent "extensive" surgery. Two-year event-free survival and overall survival were 14.4% and 50%, respectively. Among the five patients who were alive in complete remission, four had undergone extensive and complete surgery.

CONCLUSIONS

Detection of the EWS-WT1-GFT plays a major role in the diagnosis of DSRCT. No survival difference was observed according to extent of surgery, but complete surgery seemed to offer the best chance of long-term survival. High-dose chemotherapy or local radiotherapy did not appear to improve survival in this retrospective analysis, but larger prospective studies are needed to provide definitive conclusions on the role of these treatments.

Imaging of desmoplastic small round cell tumour in adults

Desmoplastic small round cell tumour (DSRCT) belongs to the histological descriptive category of small round blue cell tumours. DSRCT primarily occurs in adolescents and young adults between the ages of 15 and 25 years and has a male predominance. DSRCT is an aggressive disease with a poor prognosis; timely diagnosis is therefore critical to the management of these patients. Although their radiographic appearances overlap with other aggressive malignancies, there are certain imaging features that can suggest the diagnosis and expedite the initiation of appropriate therapy. The aim of our pictorial review is to describe the imaging findings of primary and metastatic DSRCT in adults.

Desmoplastic small round cell tumor: impact of F-FDG PET induced treatment strategy in a patient with long-term outcome

The desmoplastic small round cell tumor (DSRCT) is an uncommon and highly aggressive cancer. The role of ¹⁸F-FDG PET in management of DSRCT is little reported. We report a case of metastasized abdominal DSRCT detected in a 43-year old patient whose diagnostic and therapeutic approaches were influenced by ¹⁸F-FDG PET-CT. The patient is still alive ten years after diagnosis. ¹⁸F-FDG PET-CT seems to be a useful method for assessing therapeutic efficiency and detecting early recurrences even in rare malignancies such as DSRCT.

Outpatient and home chemotherapy with novel local control strategies in desmoplastic small round cell tumor

Desmoplastic Small Round Cell Tumor (DSRCT) has a very poor prognosis. This report illustrates novel chemotherapy and local control interventions in a 5-year old patient. The patient was treated in the outpatient setting, achieved remission, with excellent quality of life. The patient presented with massive ascites and >1000 abdominal tumors. Neoadjuvant chemotherapy included vincristine (1.5 mg/m(2)), ifosfamide (3 g/m(2)/day x 3), dexrazoxane/doxorubicin (750/75 mg/m(2)), and etoposide (150 mg/m(2)). Continuous hyperthermic peritoneal perfusion (CHPP) with cisplatin (100 mg/m(2)) was given after extensive cytoreductive surgery. This was followed by irinotecan (10 mg/m(2)/day x 5 x 2 weeks) + temozolomide monthly x 2, then abdominal radiation 30 Gy with simultaneous temozolomide (100 mg/m(2)/day x 5). A total of 12 cycles of irinotecan and temozolamide were given. Except for initial chemotherapy, subsequent courses were in the outpatient setting. Focal retroperitoneal relapse at 18 months was treated with IMRT with bevacizumab (5 mg/kg) and 2 perihepatic metastases with radio frequency ablation/cryoablation followed by chronic outpatient maintenance chemotherapy (valproic acid, cyclophosphamide, and rapamycin). Almost 2 years from diagnosis, the patient maintained an excellent quality of life. This is a novel approach to the treatment of children with massive abdomino-pelvic DSRCT.

Desmoplastic small round cell tumor in childhood: the St. Jude Children's Research Hospital experience

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a rare, primarily intra-abdominal tumor that has a poor outcome with current therapies.

PROCEDURE

We retrospectively reviewed patient characteristics, presenting symptoms, tumor pathology, treatment, and outcome of 11 pediatric patients with DSRCT at our institution.

RESULTS

The cohort included 1 female and 10 male patients. Median age at diagnosis was 14 years (range 5-21 years). In eight (73%) patients, the primary tumor was abdominal or pelvic, and in one patient each, it was submental, mediastinal, and paratesticular. Nine (82%) patients had metastatic disease. All tumors showed polyphenotypic differentiation by immunohistochemistry. The EWS-WT1 transcript was detected in six of seven tumors tested. One tumor showed rhabdomyoblastic differentiation after therapy. All patients received chemotherapy; eight underwent surgical resection, seven received primary site radiation, and four received myeloablative chemotherapy with stem-cell support. Three (27%) patients are alive 23 months, 8 years, and 10 years from diagnosis. Two died of treatment-related toxicity, six died of disease. None of the patients in whom surgery and initial chemotherapy failed to induce complete remission survived.

CONCLUSIONS

DSRCT is an aggressive malignancy that does not respond well to contemporary treatments, and patients who do not enter complete remission after initial chemotherapy and surgery appear to have a particularly dismal outcome. Patients with localized extra-abdominal disease have a better prognosis, most likely due to increased feasibility of resection. Better understanding of molecular and genetic mechanisms of tumorigenesis and treatment-related changes may contribute to development of more effective therapy for DSRCT.

Irinotecan Plus Temozolomide for Relapsed or Refractory Neuroblastoma

Purpose

To report on an irinotecan and temozolomide regimen for neuroblastoma (NB). Quality of life and minimizing toxicity were major considerations.

Patients and Methods

The plan stipulated 5-day courses of irinotecan 50 mg/m2 (1-hour infusion) and temozolomide 150 mg/m2 (oral) every 3 to 4 weeks, with a pretreatment platelet count more than 30,000/μL. Granulocyte colony-stimulating factor was used when the absolute neutrophil count was less than 1,000/μL.

Results

Forty-nine NB patients received 1 to 15 courses (median, 5). Gastrointestinal and myelosuppressive toxicities were readily managed. Lymphocyte responses to phytohemagglutinin after 2 to 10 courses (median, 3.5) were normal in 10 of 10 patients treated after nonimmunosuppressive therapy, and normalized in five of seven patients first treated less than 2 months after high-dose alkylators. Of 19 patients treated for refractory NB and assessable for response, nine showed evidence of disease regression, including two complete responses and seven objective responses. Of 17 patients treated for progressive disease, three showed evidence of disease regression, including one partial response and two objective responses. Multiple courses entailed no cumulative toxicity and controlled disease for prolonged periods in many patients, including some who were unable to complete prior treatments because of hematologic, infectious, cardiac, or renal problems.

Conclusion

This regimen has anti-NB activity, spares vital organs, is feasible with poor bone marrow reserve, causes limited immunosuppression, and allows good quality of life.

Phase II study of a protracted irinotecan schedule in children with refractory or recurrent soft tissue sarcoma

BACKGROUND

Irinotecan (CPT-11) is a novel antineoplastic agent that takes effect by inhibiting topoisomerase I. The Italian Soft Tissue Sarcoma (STS) Committee performed a multiinstitutional Phase II study to evaluate its effect on STS.

METHODS

Over a 2-year period between 2002 and 2004, 32 heavily pretreated patients were administered 60-minute infusions of irinotecan at 20 mg/m2/day, for 5 days a week, for 2 consecutive weeks. The courses were repeated every 4 weeks for at least 2 courses, unless there were signs of toxicity or disease progression. Thirty patients, 13 with peripheral primitive neuroectodermal tumor (PNET), 12 with rhabdomyosarcoma (RMS), 3 with desmoplastic small round cell tumor (DSRCT), and 2 with other STS were evaluable for response.

RESULTS

A total of 79 cycles were delivered. The main regimen-related toxicity was diarrhea, occurring in 58% of cycles with 9 episodes graded as 3 or 4. Grade 3-4 neutropenia was recorded in 10% of cycles. The overall response rate was 23% (2 complete remissions +5 partial remissions of 30 patients), 38% for PNET and 16% for RMS. In addition, 4 minor responses were noted.

CONCLUSIONS

As a single agent in the treatment of recurrent and refractory STS, irinotecan administered on a daily x5 x2 schedule revealed a noteworthy response rate in a population of heavily pretreated patients, especially in the subset of patients with PNET. Its hematologic toxicity profile warrants further investigation in association with other myelotoxic agents.

Irinotecan for children with relapsed solid tumors

Irinotecan is expected to become a new drug for childhood solid tumors. Sixteen children with relapsed solid tumors received irinotecan 180 mg/m2/day for 3 consecutive days, repeated once after 25 days off. Their original tumors were neuroblastoma in 7, rhabdomyosarcoma in 3, nephroblastoma and undifferentiated sarcoma in 2 each, and primitive neuroectodermal tumor and leiomyosarcoma in 1 each. The average age at trials was 6 years. Partial response was achieved in 5 (31.3%) (neuro-blastoma, rhabdomyosarcoma, nephroblastoma, undifferentiated sarcoma, and leiomyosarcoma), and decrease in tumor marker in the other 2. Irinotecan appears promising, and could become included in the first-line treatment.

Five-day courses of irinotecan as palliative therapy for patients with neuroblastoma

BACKGROUND

The authors describe a large experience using short courses of irinotecan for palliative therapy in patients with neuroblastoma (NB). Quality of life was a major issue in choosing this regimen for patients whose disease was resistant to standard anti-NB therapies.

METHODS

A retrospective review was conducted of all patients who were followed by the Department of Pediatrics at Memorial Sloan-Kettering Cancer Center and treated for resistant NB with irinotecan at 50 mg/m2 per day for 5 days as a 1-hour intravenous infusion. Treatment was outpatient, and there was a minimum 2-week rest period between courses. Granulocyte colony-stimulating factor was used to keep the absolute neutrophil count >500-1000/mL.

RESULTS

Forty-four patients had been treated aggressively and/or extensively before they received one or more five-day courses of irinotecan. Emetogenic, diarrheal, and myelosuppressive effects were readily managed. Hospitalizations were limited to three patients with bacteremia. Twenty-three patients had a change in therapy, although they did not have progressive disease (PD) after receiving 1 (n=10), 2 (n=3), 3 (n=1), 4 (n=6), 7 (n=1 patient), 22 (n=1 patient), or 24 (n=1) courses. The most common reasons for changing treatment were to intensify retrieval therapy or to pursue immunotherapy. Of those 23 patients, 15 patients had stable disease, 7 were not evaluable for response because of concurrent radiotherapy, and 1 patient had a major response. Twenty-one patients had PD after 1 (n=3, 2 (n=9), 4 (n=2), 5 (n=1), 6 (n=3), 7 (n=1), 9 (n=1), and 11 (n=1) courses.

CONCLUSIONS

In heavily treated patients, the regimen studied was well tolerated, allowed patients to continue most normal life activities, and produced anti-NB effects. Its modest toxicity supported use with other antitumor agents.

Camptothecin analogs (irinotecan or topotecan) plus high-dose cyclophosphamide as preparative regimens for antibody-based immunotherapy in resistant neuroblastoma

PURPOSE

We used high-dose cyclophosphamide plus topotecan/vincristine (CTV) or irinotecan (C/I) in patients with resistant neuroblastoma. The aim was to use a regimen with little risk to major organs to (a) achieve or consolidate remission in heavily treated patients and to (b) induce an immunological state conducive to passive immunotherapy with the murine 3F8 antibody.

EXPERIMENTAL DESIGN

CTV and C/I included cyclophosphamide 140 mg/kg ( approximately 4200 mg/m(2)). With CTV, topotecan 2 mg/m(2) was infused i.v. (30 min) on days 1-4 (total, 8 mg/m(2)), and vincristine 0.067 mg/kg was injected on day 1. With C/I, irinotecan, 50 mg/m(2) was infused i.v. (1 h) on days 1-5 (total, 250 mg/m(2)). Mesna and granulocyte colony-stimulating factor were used.

RESULTS

Twenty-nine patients received 38 courses of CTV, and 26 patients received 38 courses of C/I. All patients had previously received topotecan, a hemopoietic stem-cell transplant, and/or high-dose cyclophosphamide. CTV and C/I caused myelosuppression of comparably prolonged duration as follows: absolute neutrophil counts <500/ micro l lasted 5-12 days in patients who had not previously received transplant and 7-21 days in patients who were post-transplant. Other significant toxicities included typhlitis (two CTV-treated patients, one C/I-treated patient) and hemorrhagic cystitis (one C/I-treated patient). Major responses were seen in 4 (15%) of 26 CTV and 4 (17%) of 24 C/I-treated patients with assessable disease. Bone marrow disease resolved in 5 (28%) of 18 CTV-treated patients and in 4 (27%) of 15 C/I-treated patients. 3F8 after CTV or C/I was not blocked by neutralizing antibodies, consistent with the desired immunosuppressive effect of high-dose cyclophosphamide.

CONCLUSIONS

CTV and C/I require transfusional and antibiotic support but otherwise entail tolerable morbidity. They have modest antineuroblastoma activity in heavily treated patients and are good preparative regimens for passive immunotherapy with monoclonal antibodies.

Pediatric soft tissue sarcomas

Many of the soft tissue sarcomas that occur in children are of the same histology as those in adults; however, the relative prevalence of these sarcomas is different between children and adults. In some cases, the biologic behavior of pediatric sarcomas is more benign than that in adults. Treatment for sarcomas in children is also different. Pediatric sarcomas are more commonly responsive to chemotherapy. Furthermore, in children who are still growing, surgery and radiation are associated with higher morbidity than in adults. This article discusses the diagnosis and treatment of rhabdomyosarcoma and undifferentiated sarcomas, with an emphasis on surgical considerations, and the diagnosis and treatment of nonrhabdomyosarcomatous soft tissue sarcomas in children.

Phase I study of irinotecan in pediatric patients with malignant solid tumors

PURPOSE

To determine the dose-limiting toxicity, maximum tolerated dose, and potential efficacy of irinotecan in children with refractory malignant solid tumors.

PATIENTS AND METHODS

In the present phase I clinical trial, 28 patients received irinotecan 50 to 200 mg/m2 per day by intravenous 2-hour infusion over the course of 3 days, repeated once after an interval of 25 days. Fifty-one treatment courses were administered to these patients.

RESULTS

Dose-limiting toxicities were observed at the dose of 200 mg/m2 per day for 3 days. Diarrhea and hematopoietic toxicities were the dose-limiting factors, and the former required support with intravenous fluid administration. The occurrence of vomiting was variable. Decreases in clinical tumor marker levels were observed in the majority of patients who received two cycles of irinotecan 80 mg/m2 per day to 200 mg/m2 per day over the course of 3 days, and partial response was attained in four patients who received irinotecan in two cycles of 140 mg/m2 per day to 200 mg/m2 per day over the course of 3 days. Pharmacokinetic studies showed that the plasma concentration of irinotecan and its active metabolite SN-38 ranged from 93 to 2,820 ng/mL and 5.2 to 34.8 ng/mL, respectively, during 3-day infusions of irinotecan 200 mg/m2 per day. The mean clearance of irinotecan was 14.54 L/h per m2 (range 8.45-20.83 L/h per m2).

CONCLUSION

The maximum tolerated dose was determined to be a dose of irinotecan between 160 mg/m2 per day and 180 mg/m2 per day administered over the course of 3 consecutive days on an inpatient basis, repeated once after 25 days off, and our results indicate that irinotecan is a promising anticancer agent that is worthy of phase II trials in pediatric solid tumors.