Efficacy of ifosfamide and doxorubicin given as a phase II "window" in children with newly diagnosed metastatic rhabdomyosarcoma: a report from the Intergroup Rhabdomyosarcoma Study Group

Photoactive metabolite mediated photodynamic therapy of Rhabdomyosarcoma cell lines using medicinal plants and Doxorubicin co-treatments

BACKGROUND

Medicinal plant-mediated combinational therapies have gained importance globally due to minimal side effects and enhanced treatment outcomes compared to single-drug modalities. We aimed to analyze the cytotoxic potential of each conventional treatment i.e., photodynamic therapy (PDT), chemotherapy (doxorubicin hydrochloride; Dox-HCl) with or without various concentrations of medicinal plant extracts (PE) on soft tissue cancer Rhabdomyosarcoma (RD) cell line.

METHODS

The Rhabdomyosarcoma (RD) cell line was cultured and treated with Photosensitizer (Photosense (AlPc4)), Chemo (Dox-HCl), and their combinations with different concentrations of each plant extract i.e., Thuja occidentalis, Moringa oleifera, Solanum surattense. For the source of illumination, a Diode laser (λ = 630 nm ± 1 nm, Pmax = 1.5 mW) was used. Photosensitizer uptake time (∼ 45 min) was optimized through spectrophotometric measurements (absorption spectroscopy). Drug response of each treatment arm was assessed post 24 h of administration using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5- 5-diphenyl-2 H- tetrazolium bromide (MTT) assay.

RESULTS

PE-mediated Chemo-Photodynamic therapy (PDT) exhibited synergistic effects (CI < 1). Moreover, Rhabdomyosarcoma culture pretreated with various plant extracts for 24 h exhibited significant inhibition of cell viability however most effective outcomes were shown by low and high doses of Moringa oleifera compared to other plant extracts. Post low doses treated culture with all plant extracts followed by PDT came up with more effectiveness when compared to all di-therapy treatments.

CONCLUSION

The general outcome of this work shows that the ethanolic plant extracts (higher doses) promote the death of cancerous cells in a dose-dependent way and combining Dox-HCl and photo-mediated photodynamic therapy can yield better therapeutic outcomes.

Contemporary preclinical mouse models for pediatric rhabdomyosarcoma: from bedside to bench to bedside

Background

Rhabdomyosarcoma (RMS) is the most common pediatric soft-tissue malignancy, characterized by high clinicalopathological and molecular heterogeneity. Preclinical in vivo models are essential for advancing our understanding of RMS oncobiology and developing novel treatment strategies. However, the diversity of scholarly data on preclinical RMS studies may challenge scientists and clinicians. Hence, we performed a systematic literature survey of contemporary RMS mouse models to characterize their phenotypes and assess their translational relevance.

Methods

We identified papers published between 01/07/2018 and 01/07/2023 by searching PubMed and Web of Science databases.

Results

Out of 713 records screened, 118 studies (26.9%) were included in the qualitative synthesis. Cell line-derived xenografts (CDX) were the most commonly utilized (n = 75, 63.6%), followed by patient-derived xenografts (PDX) and syngeneic models, each accounting for 11.9% (n = 14), and genetically engineered mouse models (GEMM) (n = 7, 5.9%). Combinations of different model categories were reported in 5.9% (n = 7) of studies. One study employed a virus-induced RMS model. Overall, 40.0% (n = 30) of the studies utilizing CDX models established alveolar RMS (aRMS), while 38.7% (n = 29) were embryonal phenotypes (eRMS). There were 20.0% (n = 15) of studies that involved a combination of both aRMS and eRMS subtypes. In one study (1.3%), the RMS phenotype was spindle cell/sclerosing. Subcutaneous xenografts (n = 66, 55.9%) were more frequently used compared to orthotopic models (n = 29, 24.6%). Notably, none of the employed cell lines were derived from primary untreated tumors. Only a minority of studies investigated disseminated RMS phenotypes (n = 16, 13.6%). The utilization areas of RMS models included testing drugs (n = 64, 54.2%), studying tumorigenesis (n = 56, 47.5%), tumor modeling (n = 19, 16.1%), imaging (n = 9, 7.6%), radiotherapy (n = 6, 5.1%), long-term effects related to radiotherapy (n = 3, 2.5%), and investigating biomarkers (n = 1, 0.8%). Notably, no preclinical studies focused on surgery.

Conclusions

This up-to-date review highlights the need for mouse models with dissemination phenotypes and cell lines from primary untreated tumors. Furthermore, efforts should be directed towards underexplored areas such as surgery, radiotherapy, and biomarkers.

A case of complete response to chemotherapy followed by cystectomy for adult-onset rhabdomyosarcoma of the bladder

We report a case of alveolar rhabdomyosarcoma of the bladder which achieved complete response with neoadjuvant chemotherapy and surgery. A 58-year-old man was referred to our hospital due to bladder tumor discovered with urinary frequency and gross hematuria. Pathological diagnosis was alveolar rhabdomyosarcoma arising in the bladder which was an extremely rare type. Because the images showed no metastasis except for the right external iliac lymph node, curative treatment was performed consisting of cystectomy besides neoadjuvant chemotherapy using adriamycin and ifosfamide. No residual tumor was found in the extracted bladder specimen. He has been disease free at 12-month follow-up.

Combination therapy of doxorubicin and Sildenafil inhibits the growth of pediatric rhabdomyosarcoma

BACKGROUND

Overexpression of phosphodiesterase type 5 (PDE5) has been detected in many types of malignant tumors. Sildenafil, a potent and selective inhibitor of a cGMP-specific PDE5, has been found to enhance the cytotoxic activity of different chemotherapeutic agents including doxorubicin. The combined therapy of doxorubicin with Sildenafil might reduce the possible side effects of chemotherapy while maintaining synergistic anticancer activity. The present study explored for the first time the effects of Sildenafil, alone and in combination with doxorubicin, on pediatric RMS cells.

METHODS

Human RMS cells lines RH30 and RD were used. Western blotting and RT-PCR were performed to analyze PDE5 expression in RMS cells. Cell viability was determined using MTT assay. Cell migration was analyzed via transwell chambers, clonal growth and mitotic cell death were analyzed using the clonogenic assay. FACS analysis was performed to evaluate reactive oxygen species (ROS) and apoptosis.

RESULTS

Sildenafil significantly decreased cell viability and migration of RD and RH30 cells. The exposure of RMS cells to doxorubicin resulted in a dose-dependent decrease in their viability. Simultaneous administration of Sildenafil enhanced this effect. The incubation of the RMS cells with Sildenafil in the presence of doxorubicin significantly increased the proportion of apoptotic cells and ROS production compared to the treatment with Sildenafil alone.

CONCLUSIONS

The results of our study indicate a link between PDE5 inhibition by Sildenafil and decreased calcium signalling leading to significantly impaired viability, migration, and colony forming of RMS cells. Increased ROS production and apoptosis are mechanisms relevantly contributing to this observation.

Phase 1 trial of olaratumab monotherapy and in combination with chemotherapy in pediatric patients with relapsed/refractory solid and central nervous system tumors

Olaratumab is a monoclonal antibody that specifically binds to platelet-derived growth factor receptor alpha (PDGFRα) and blocks receptor activation. We conducted a phase 1 trial to evaluate the safety of olaratumab and determine a recommended dose in combination with three different chemotherapy regimens in children. Patients <18 years with relapsed/refractory solid or central nervous system tumors were enrolled to two dose levels of olaratumab. Patients received olaratumab monotherapy at 15 mg/kg (Part A) or 20 mg/kg (Part B) on Days 1 and 8 of the first 21-day cycle, followed by olaratumab combined with standard fixed doses of chemotherapy with doxorubicin, vincristine/irinotecan, or high-dose ifosfamide by investigator choice for subsequent 21-day cycles. In Part C, patients received olaratumab 20 mg/kg plus assigned chemotherapy for all cycles. Parts A-C enrolled 68 patients across three chemotherapy treatment arms; olaratumab in combination with doxorubicin (N = 16), vincristine/irinotecan (N = 26), or ifosfamide (N = 26). Three dose-limiting toxicities (DLTs) occurred during olaratumab monotherapy (at 15 mg/kg, grade [G] 4 alanine aminotransferase [ALT]; at 20 mg/kg, G3 lung infection and G3 gamma-glutamyl transferase). One DLT occurred during vincristine/irinotecan with olaratumab 20 mg/kg therapy (G3 ALT). Treatment-emergent adverse events ≥G3 in >25% of patients included neutropenia, anemia, leukopenia, lymphopenia, and thrombocytopenia. Pharmacokinetic profiles of olaratumab with chemotherapy were within the projected range based on adult data. There was one complete response (rhabdomyosarcoma [Part B vincristine/irinotecan arm]) and three partial responses (two rhabdomyosarcoma [Part A doxorubicin arm and Part C doxorubicin arm]; one pineoblastoma [Part B vincristine/irinotecan arm]). Olaratumab was tolerable and safely administered in combination with chemotherapy regimens commonly used in children and adolescents.

Current and Future Treatment Strategies for Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children, and can be subcategorized histologically and/or based on PAX-FOXO1 fusion gene status. Over the last four decades, there have been no significant improvements in clinical outcomes for advanced and metastatic RMS patients, underscoring a need for new treatment options for these groups. Despite significant advancements in our understanding of the genomic landscape and underlying biological mechanisms governing RMS that have informed the identification of novel therapeutic targets, development of these therapies in clinical trials has lagged far behind. In this review, we summarize the current frontline multi-modality therapy for RMS according to pediatric protocols, highlight emerging targeted therapies and immunotherapies identified by preclinical studies, and discuss early clinical trial data and the implications they hold for future clinical development.

Addition of dose-intensified doxorubicin to standard chemotherapy for rhabdomyosarcoma (EpSSG RMS 2005): a multicentre, open-label, randomised controlled, phase 3 trial

BACKGROUND

Rhabdomyosarcoma is an aggressive tumour that can develop in almost any part of the body. Doxorubicin is an effective drug against rhabdomyosarcoma, but its role in combination with an established multidrug regimen remains controversial. Therefore, we aimed to evaluate the possible benefit of early dose intensification with doxorubicin in patients with non-metastatic rhabdomyosarcoma.

METHODS

We did a multicentre, open-label, randomised controlled, phase 3 trial involving 108 hospitals from 14 countries. We included patients older than 6 months but younger than 21 years with a pathologically proven diagnosis of rhabdomyosarcoma. We assigned each patient to a specific subgroup according to the EpSSG stratification system. Those with embryonal rhabdomyosarcoma incompletely resected and localised at unfavourable sites with or without nodal involvement, or those with alveolar rhabdomyosarcoma without nodal involvement were considered at high risk of relapse. These high-risk patients were randomly assigned (1:1) to receive either nine cycles of IVA (ifosfamide 3 g/m2 given as a 3-h intravenous infusion on days 1 and 2, vincristine 1·5 mg/m2 weekly during the first 7 weeks then only on day 1 of each cycle [given as a single intravenous injection], and dactinomycin 1·5 mg/m2 on day 1 given as a single intravenous injection) or four cycles of IVA with doxorubicin 30 mg/m2 given as a 4-h intravenous infusion on days 1 and 2 followed by five cycles of IVA. The interval between cycles was 3 weeks. Randomisation was done using a web-based system and was stratified (block sizes of four) by enrolling country and risk subgroup. Neither investigators nor patients were masked to treatment allocation. The primary endpoint was 3-year event-free survival assessed by the investigator at each centre in the intention-to-treat population. Patients who received at least one dose of study treatment were considered in the safety analysis. In agreement with the independent data monitoring committee, the study was closed to patient entry on Dec 16, 2013, after futility analysis. This trial is registered with EudraCT, number 2005-000217-35, and is currently in follow-up.

FINDINGS

Between Oct 1, 2005, and Dec 16, 2013, 484 patients were randomly assigned to receive each chemotherapy regimen (242 in the IVA group and 242 in the IVA plus doxorubicin group). Median follow-up was 63·9 months (IQR 44·6-78·9). The 3-year event-free survival was 67·5% (95% CI 61·2-73·1) in the IVA plus doxorubicin group and 63·3% (56·8-69·0) in the IVA group (hazard ratio 0·87, 95% CI 0·65-1·16; p=0·33). Grade 3-4 leucopenia (232 [93%] of 249 patients in the IVA plus doxorubicin group vs 194 [85%] of 227 in the IVA group; p=0·0061), anaemia (195 [78%] vs 111 [49%]; p<0·0001), thrombocytopenia (168 [67%] vs 59 [26%]; p<0.0001), and gastrointestinal adverse events (78 [31%] vs 19 [8%]; p<0·0001) were significantly more common in the IVA plus doxorubicin group than in the IVA group. Grade 3-5 infections (198 [79%] vs 128 [56%]; p<0·0001) were also significantly more common in the IVA plus doxorubicin group than in the IVA group, in which one patient had grade 5 infection. Two treatment-related deaths were reported (one patient developed septic shock and one affected by Goldenhar syndrome developed intractable seizures) in the IVA plus doxorubicin group, both occurring after the first cycle of treatment, and none were reported in the IVA group.

INTERPRETATIONS

The addition of dose-intensified doxorubicin to standard IVA chemotherapy did not show a significant improvement in the outcome of patients with high-risk non-metastatic rhabdomyosarcoma. Therefore, the IVA chemotherapy regimen should remain the standard of care for patients with localised rhabdomyosarcoma in Europe.

FUNDING

Fondazione Città della Speranza, Italy, and the Association Léon Berard Enfant Cancéreux, France.

Fifty years of rhabdomyosarcoma studies on both sides of the pond and lessons learned

We review and summarize the highlights of almost five decades of cooperative group trials in rhabdomyosarcoma on both sides of the Atlantic, concentrating on chemotherapy regimens, what has been learned, and where remaining challenges are. The most important achievements have been to decrease or omit the dose of alkylator therapy for many patients, to clarify after much controversy that doxorubicin does not improve the outcome of patients even in the highest risk groups, and to show that high dose chemotherapy and stem cell rescue do not improve the outcome of the highest risk patients. In North America, vincristine/actinomycin/cyclophosphamide (VAC) remains an important part of therapy, whereas in Europe the alkylating agent of choice is ifosfamide. The highest risk patients, namely those with the poorest prognostic score, have had no improvement in outcome since the first cooperative group trial in 1972 and remain the greatest challenge. Philosophical differences between European and North American strategies still revolve somewhat around the total burden of therapy received, that is should certain groups of patients be spared aggressive local control in order to reduce late effects, recognizing that it is not possible to identify priori the children that can be cured with this approach exposing the whole population to a higher risk of relapse. Collaboration and joining resources may help answer some difficult questions.

Pleomorphic rhabdomyosarcoma infiltrating thoracic spine in a 59-year-old female patient: Case report

Rhabdomyosarcoma (RMS) represents a malignant tumor of skeletal muscle cells arising from rhabdomyoblasts. RMS represents the most common soft tissue sarcoma in children. In adults it is uncommon and accounts for less than 1% of all malignant solid tumors. While treatment protocols are well known for children, there is no standardized regimen in adults. This is one reason, why the outcome in adults is worse than in children. We present the case of a 59-year-old female patient with pleomorphic rhabdomyosarcoma (PRMS) infiltrating the thoracic spine. Multimodality treatment was performed including en-bloc resection, adjuvant multidrug chemotherapy and radiation beam therapy. The patient was tumor free and had no relapse within 6 month follow-up.

Embryonal rhabdomyosarcoma of the perineum in an adult: a case report

BACKGROUND

We report the case of an adult patient with embryonal rhabdomyosarcoma of the perineum admitted to our practice at Joliot Curie Institute in Dakar. It is a rare tumor at this age and has a bad prognosis at this localization.

CASE PRESENTATION

We describe the case of a 22-year-old African man admitted for a perineal mass that had evolved over 6 months. He complained of tenesmus, obstinate constipation, and dysuria. A clinical examination revealed perineal swelling spread over his anus, scrotum, penis, testicles, and inguinal lymph nodes. A perineal ultrasound and computed tomography scan showed a large mass driving his testicles forward with regional lymph node metastases. An ultrasound-guided biopsy showed embryonal rhabdomyosarcoma on histology and immunohistochemistry, with strong positivity of neural cell adhesion molecule and myogenin while results for cytokeratin AE1/AE3, cluster of differentiation 45, synaptophysin, and chromogranin were negative. Our patient was classified T2N1M1. Outcome was quickly marked by occlusive syndrome and colostomy. Our patient did not opt for chemotherapy and died after 6 months of follow-up.

CONCLUSIONS

The embryonic RMS of the adult is a rare disease. Despite the sensitivity to chemotherapy and surgery. Localization to perineum remains poor prognosis.

Presurgical window of opportunity trial design as a platform for testing anticancer drugs: Pros, cons and a focus on breast cancer

The high attrition rate is a major issue in anticancer drug development. Among the alternative trial designs, presurgical window of opportunity trials envision a short course treatment in the time window between diagnostic biopsy and surgery in a moderately-sized patient population. This approach allows testing therapeutics when pre- and post-treatment tumor tissues are available for comprehensive molecular analyses. The emerging evidence may help define the ability of a given agent to modulate its target(s) and help obtain a broader picture of the molecular changes operated by the treatment. The resulting gain may outweigh the potential harms for patients in the early disease setting. Window of opportunity trials have been extensively applied to breast cancer. Overall, a wider use of these trial designs might lead to the identification of potential responders, ineffective drugs or combinations, and ultimately contribute to enhance the efficiency of the clinical developmental process.

Identification of synthetic lethality of PLK1 inhibition and microtubule-destabilizing drugs

Polo-like kinase 1 (PLK1) is frequently overexpressed in cancer, which correlates with poor prognosis. Therefore, we investigated PLK1 as therapeutic target using rhabdomyosarcoma (RMS) as a model. Here, we identify a novel synthetic lethal interaction of PLK1 inhibitors and microtubule-destabilizing drugs in preclinical RMS models and elucidate the underlying molecular mechanisms of this synergism. PLK1 inhibitors (i.e., BI 2536 and BI 6727) synergistically induce apoptosis together with microtubule-destabilizing drugs (i.e., vincristine (VCR), vinblastine (VBL) and vinorelbine (VNR)) in several RMS cell lines (combination index <0.9) including a patient-derived primary RMS culture. Importantly, PLK1 inhibitors and VCR cooperate to significantly suppress RMS growth in two in vivo models, including a mouse xenograft model, without causing additive toxicity. In addition, no toxicity was observed in non-malignant fibroblast or myoblast cultures. Mechanistically, BI 2536/VCR co-treatment triggers mitotic arrest, which initiates mitochondrial apoptosis by inactivation of antiapoptotic BCL-2 family proteins, followed by BAX/BAK activation, production of reactive oxygen species (ROS) and activation of caspase-dependent or caspase-independent effector pathways. This conclusion is supported by data showing that BI 2536/VCR-induced apoptosis is significantly inhibited by preventing cells to enter mitosis, by overexpression of BCL-2 or a non-degradable MCL-1 mutant, by BAK knockdown, ROS scavengers, caspase inhibition or endonuclease G silencing. This identification of a novel synthetic lethality of PLK1 inhibitors and microtubule-destabilizing drugs has important implications for developing PLK1 inhibitor-based combination treatments.

Relapse after localized rhabdomyosarcoma: Evaluation of the efficacy of second-line chemotherapy

PURPOSE

About one-third of patients with rhabdomyosarcoma relapse despite appropriate treatment and experience a poor outcome. Little meaningful improvement in the outcome of this disease has been observed over the last 30 years. There is no clear international recommendation concerning the use of salvage chemotherapy at relapse. A retrospective multicenter analysis was therefore conducted to analyze the efficacy of various second-line chemotherapy regimens in this setting.

METHODS

Forty-nine patients under the age of 18, with initially localized rhabdomyosarcoma, who relapsed after first complete remission, treated in three SFCE centers (Société Française des Cancers de l'Enfant) between 1995 and 2013, were analyzed.

RESULTS

First relapse occurred after a median interval of 22 months and remained localized in 71.4% of cases. All patients received second-line chemotherapy with an overall response to this salvage therapy of 39.1%. Best specific response rates were 73.3 and 42.9% for carboplatin/epirubicin/vincristine-ifosfamide/vincristine/etoposide (CEV/IVE) (15 patients) and vincristine/irinotecan ± temozolomide (VI[T]) (seven patients), respectively. Overall, 40 patients (81.6%) were then eligible for delayed local treatment (surgery and/or radiotherapy) and 30 of them (61.2%) achieved second complete remission. After a median follow-up of 5.4 years since the diagnosis of first relapse, 5-year overall survival is 49.4% (95% CI: 34.2-64.6).

CONCLUSION

Salvage chemotherapy plays a central role in the management of patients with relapsed rhabdomyosarcoma. CEV/IVE and VI(T) regimens can be recommended as neoadjuvant chemotherapy before local treatment for patients with relapsed rhabdomyosarcoma.

Drug-induced acute kidney injury in children

Acute kidney injury (AKI) is a serious problem occurring in anywhere between 8 and 30% of children in the intensive care unit. Up to 25% of these cases are believed to be the result of pharmacotherapy. In this review we have focused on several relevant drugs and/or drug classes, which are known to cause AKI in children, including cancer chemotherapeutics, non-steroidal anti-inflammatory drugs and antimicrobials. AKI demonstrates a steady association with increased long term risk of poor outcomes including chronic kidney disease and death as determined by the extent of injury. For this reason it is important to understand the causality and implications of these drugs and drug classes. Children occupy a unique patient population, advocating the importance of understanding how they are affected dissimilarly compared with adults. While the kidney itself is likely more susceptible to injury than other organs, the inherent toxicity of these drugs also plays a major role in the resulting AKI. Mechanisms involved in the toxicity of these drugs include oxidative damage, hypersensitivity reactions, altered haemodynamics and tubule obstruction and may affect the glomerulus and/or the tubules. Understanding these mechanisms is critical in determining the most effective strategies for treatment and/or prevention, whether these strategies are less toxic versions of the same drugs or add-on agents to mitigate the toxic effect of the existing therapy.

Histologic and clinical characteristics can guide staging evaluations for children and adolescents with rhabdomyosarcoma: a report from the Children's Oncology Group Soft Tissue Sarcoma Committee

PURPOSE

To simplify the recommended staging evaluation by correlating tumor and clinical features with patterns of distant metastasis in newly diagnosed patients with embryonal rhabdomyosarcoma (ERMS) or alveolar rhabdomyosarcoma (ARMS).

PATIENTS AND METHODS

Patient data from the Intergroup Rhabdomyosarcoma Study Group and the Children's Oncology Group over two periods were analyzed: 1991 to 1997 and 1999 to 2004. We used recursive partitioning analyses to identify factors (including histology, age, regional nodal and distant metastatic status, tumor size, local invasiveness, and primary site) that divided patients into subsets with the most different rates of metastatic disease.

RESULTS

Of the 1,687 patients analyzed, 5.7% had lung metastases, 4.8% had bone involvement, and 6% had bone marrow (BM) involvement. Rhabdomyosarcoma (RMS) without local invasion (T1) had a low rate of metastasis for all distant sites, especially ERMS (0% bone, 0% BM). ARMS with local invasion (T2) had a higher rate of metastasis for all distant sites (13% lung, 18% bone, 23% BM). ERMS, T2 also had a higher rate of metastatic lung involvement (9%). The likelihood of bone or BM involvement increased in the presence of lung metastases (41% with, 6% without). Regional nodal metastases (N1) predicted a high rate of metastasis in all distant sites (14% lung, 14% bone, 18% BM). A staging algorithm was developed.

CONCLUSION

Staging studies in childhood RMS can be tailored to patients' presenting characteristics. Bone marrow aspirate and biopsy and bone scan are unnecessary in at least one third of patients with RMS.

Relevance of historical therapeutic approaches to the contemporary treatment of pediatric solid tumors

Children with solid tumors, most of which are malignant, have an excellent prognosis when treated on contemporary regimens. These regimens, which incorporate chemotherapeutic agents and treatment modalities used for many decades, have evolved to improve relapse-free survival and reduce long-term toxicity. This review discusses the evolution of the treatment regimens employed for management of the most common solid tumors, emphasizing the similarities between contemporary and historical regimens. These similarities allow the use of historical patient cohorts to identify the late effects of successful therapy and to evaluate remedial interventions for these adverse effects.

Sequestration of AS-DACA into acidic compartments of the membrane trafficking system as a mechanism of drug resistance in rhabdomyosarcoma

The accumulation of weakly basic drugs into acidic organelles has recently been described as a contributor to resistance in childhood cancer rhabdomyosarcoma (RMS) cell lines with differential sensitivity to a novel topoisomerase II inhibitor, AS-DACA. The current study aims to explore the contribution of the endocytic pathway to AS-DACA sequestration in RMS cell lines. A 24-fold differential in AS-DACA cytotoxicity was detected between the RMS lines RD and Rh30. The effect of inhibitors of the endocytic pathway on AS-DACA sensitivity in RMS cell lines, coupled with the variations of endosomal marker expression, indicated the late endosomal/lysosomal compartment was implicated by confounding lines of evidence. Higher expression levels of Lysosomal-Associated Membrane Protein-1 (LAMP1) in the resistant RMS cell line, RD, provided correlations between the increased amount and activity of these compartments to AS-DACA resistance. The late endosomal inhibitor 3-methyladenine increased AS-DACA sensitivity solely in RD leading to the reduction of AS-DACA in membrane trafficking organelles. Acidification inhibitors did not produce an increase in AS-DACA sensitivity nor reduce its sequestration, indicating that the pH partitioning of weakly basic drugs into acidic compartments does not likely contribute to the AS-DACA sequestering resistance mechanism evident in RMS cells.

Update on rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a malignant childhood tumor of mesenchymal origin that currently has a greater than 70% overall 5-year survival. Multimodality treatment is determined by risk stratification according to pretreatment stage, postoperative group, histology, and site of the primary tumor. Pretreatment staging is dependent on primary tumor site, size, regional lymph node status, and presence of metastases. Unique to RMS is the concept of postoperative clinical grouping that assesses the completeness of disease resection and takes into account lymph node evaluation. At all tumor sites, the clinical grouping, and therefore completeness of resection, is an independent predictor of outcome. Overall, the prognosis for RMS is dependent on primary tumor site, patient age, completeness of resection, extent of disease, including the presence and number of metastatic sites and histology and biology of the tumor cells. Therefore, the surgeon plays a vital role in RMS by contributing to risk stratification for treatment, local control of the primary tumor, and outcome. The current state-of-the-art treatment is determined by treatment protocols developed by the Soft Tissue Sarcoma Committee of the children's Oncology Group.

Intracellular trafficking as a determinant of AS-DACA cytotoxicity in rhabdomyosarcoma cells

BACKGROUND

Rhabdomyosarcoma (RMS) is a malignant soft tissue sarcoma derived from skeletal muscle precursor cells, which accounts for 5-8% of all childhood malignancies. Disseminated RMS represents a major clinical obstacle, and the need for better treatment strategies for the clinically aggressive alveolar RMS subtype is particularly apparent. Previously, we have shown that the acridine-4-carboxamide derivative AS-DACA, a known topoisomerase II poison, is potently cytotoxic in the alveolar RMS cell line RH30, but is 190-fold less active in the embryonal RMS cell line RD. Here, we investigate the basis for this selectivity, and demonstrate in these RMS lines, and in an AS-DACA- resistant subclone of RH30, that AS-DACA-induced cytotoxicity correlates with the induction of DNA double strand breaks.

RESULTS

We show that inhibition of the multidrug-resistance associated protein (MRP1) has no effect on AS-DACA sensitivity. By exploiting the pH-dependent fluorescence properties of AS-DACA, we have characterized its intracellular distribution, and show that it concentrates in the cell nucleus, as well as in acidic vesicles of the membrane trafficking system. We show that fluorescence microscopy can be used to determine the localization of AS-DACA to the nuclear and cytoplasmic compartments of RMS cells grown as spheroids, penetrance being much greater in RH30 than RD spheroids, and that the vesicular signal leads the way into the spheroid mass. EEA1 and Rab5 proteins, molecular markers expressed on early-endosomal vesicles, are reduced by >50% in the sensitive cell lines.

CONCLUSION

Taking the evidence as a whole, suggests that endosomal vesicle trafficking influences the toxicity of AS-DACA in RMS cells.

In vitro assessment of novel transcription inhibitors and topoisomerase poisons in rhabdomyosarcoma cell lines

PURPOSE

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Current chemotherapy regimes include the topoisomerase II poison etoposide and the transcription inhibitor actinomycin D. Poor clinical response necessitate identification of new agents to improve patient outcomes.

METHODS

We assessed the in vitro cytotoxicity (MTT assay) of DNA intercalating agents in five established human RMS cell lines. These include novel classes of transcription inhibitors and topoisomerase poisons, previously shown to have potential as anti-cancer agents.

RESULTS

Amongst the former agents, bisintercalating bis(9-aminoacridine-4-carboxamides) linked through the 9-position, and bis(phenazine-1-carboxamides) linked via their side chains, are compared with established transcription inhibitors. Amongst the latter, monofunctional acridine-4-carboxamides related to N-[2-(dimethylamino)ethyl]acridine-4-carboxamide, DACA, are compared with established topoisomerase poisons.

CONCLUSIONS

Our findings specifically highlight the topoisomerase poison 9-amino-DACA, its 5-methylsulphone derivative, AS-DACA, and the bis(phenazine-1-carboxamide) transcription inhibitor MLN944/XR5944, currently in phase I trial, as candidates for further research into new agents for the treatment of RMS.

Primary renal sarcomas in the Intergroup Rhabdomyosarcoma Study Group (IRSG) experience, 1972-2005: A report from the Children's Oncology Group

PURPOSE

To describe clinical and pathologic characteristics and outcome of patients with renal sarcomas.

PATIENTS/METHODS

The IRSG database includes newly diagnosed patients <21 years old with rhabdomyosarcoma (RMS) or undifferentiated sarcoma (UDS). We identified patients with renal sarcoma and reviewed their charts.

RESULTS

Ten of the 5,746 eligible IRSG patients enrolled from 1972 to 2005 had primary renal embryonal RMS (N = 6) or UDS (N = 4). Anaplasia was present in six (60%) of the tumors. Patients' ages ranged from 2.6 to 17.8 years. Tumor diameters ranged from 7 to 15 cm (median, 12 cm). At diagnosis, seven patients had localized disease: four underwent complete removal of tumor (Group I), two had microscopic residual (Group II), and one had gross residual tumor (Group III). Three patients had distant metastases (Group IV) in lungs and bone. Nine patients received vincristine, actinomycin D and cyclophosphamide (VAC). Two Group I patients received no radiation therapy (XRT); others received XRT to the primary tumor and to some metastatic sites. Nine patients achieved complete disappearance of tumor, six due to the initial operation. Tumors recurred in lung (N = 2) or brain (N = 1) in Group IV patients; each died within 16 months. The Group III patient died of Aspergillus pneumonia. The six Group I and II patients survive, continuously disease-free, at 2.7-17.3 years (median, 4.7 years).

CONCLUSIONS

Patients with renal sarcomas often present with large tumors, many of them containing anaplastic features. Removing all gross disease at diagnosis, if feasible, is a critical component of treatment to curing patients with renal sarcoma.

Results in patients with cranial parameningeal sarcoma and metastases (Stage 4) treated on Intergroup Rhabdomyosarcoma Study Group (IRSG) Protocols II-IV, 1978-1997: report from the Children's Oncology Group

PURPOSE

Determine outcome of patients with cranial parameningeal sarcoma and concurrent metastases treated on Intergroup Rhabdomyosarcoma Study Group (IRSG) Protocols II-IV.

PATIENTS

We identified 91 patients in the database, which includes newly diagnosed subjects <21 years old with rhabdomyosarcoma (RMS) and undifferentiated sarcoma, and reviewed their charts in detail.

RESULTS

The 54 males and 37 females were <1-19 years at diagnosis. Primary sites were nasopharynx-nasal cavity, middle ear/mastoid and parapharyngeal area ("better" sites, 55%), paranasal sinus and infratemporal-pterygopalatine area ("worse" sites, 42%), and other (3%). Sixty-eight percent of informative patients had direct intracranial extension. Major metastatic sites at diagnosis were lung (63%), bone marrow (33%), and bone (27%). Treatment included vincristine, actinomycin D, and cyclophosphamide (VAC) chemotherapy and radiotherapy to the primary tumor and up to five metastatic sites/tissues.

OUTCOME

The estimated 10-year failure-free survival (FFS) rate was 32% (95% confidence interval [CI]: 22%, 42%). Sixty patients had progressive disease (N = 49) or death as a first event (N = 11); another developed myelodysplastic syndrome and died. Sites of first progression/relapse were distant (55%), local (12%), CNS extension (8%), mixed (6%), and uncertain (18%). Factors indicating likelihood of 10-year FFS included tumor arising in "better" versus "worse" sites (FFS 46% vs. 18%, P = 0.02) and embryonal versus other histology (FFS 37% vs. 19%, P = 0.06).

CONCLUSIONS

Cure was possible for some patients with metastatic cranial parameningeal sarcoma. Patients with the best outlook had embryonal RMS located in the nasopharynx/nasal cavity, middle ear/mastoid, or parapharyngeal region. Distant metastases were the most frequent type of recurrence, indicating that more effective systemic agents are needed to eliminate residual disease.

Prognostic factors in metastatic rhabdomyosarcomas: results of a pooled analysis from United States and European cooperative groups

PURPOSE

To identify risk factors associated with outcome in children with metastatic rhabdomyosarcoma in a large cohort of patients

PATIENTS AND METHODS

Pooled data were obtained from 788 patients treated in nine studies performed by European and American cooperative groups. Clinical factors, including age, histology, site of primary, and site(s) and number of sites of metastatic disease, were correlated with event-free survival (EFS) and overall survival (OS).

RESULTS

Seven hundred eighty-eight patients were eligible for analysis. The 3-year OS and EFS were 34% (SE, 1.7) and 27% (SE, 1.6), respectively. By univariate analysis, 3-year EFS was significantly and adversely influenced by age, alveolar histology, location of primary tumor in unfavorable site (defined as extremity and "other" sites), presence of three or more sites of metastatic disease, and the presence of bone or bone marrow involvement. By multivariate analysis, EFS was strongly correlated to all factors except histology. Relative risks were 1.6 for age younger than 1 year or at least 10 years, 1.4 for unfavorable site of primary tumor, 1.4 for bone or bone marrow involvement, 1.4 for three or more metastatic sites. EFS was 50% for patients without any of these four adverse factors and was respectively 42%, 18%, 12%, and 5% in patients with one, two, three, or four factors (P < .0001).

CONCLUSION

This analysis identified subsets of patients with metastatic rhabdomyosarcoma with different outcomes to current therapy and offers a strategy to define patient candidates for experimental approaches to treatment.

Optimal management strategies for rhabdomyosarcoma in children

Rhabdomyosarcoma is the most common sarcoma of childhood. Fortunately, the goal of cure is realistic for the majority of patients with localized tumors. However, management of these patients remains challenging. The fact that the tumor arises in a wide variety of primary sites, some of which are associated with specific patterns of local invasion, regional lymph node spread, and therapeutic response, requires physicians to be familiar with site-specific staging and treatment details. In addition, rhabdomyosarcoma requires multimodality therapy that can be associated with significant acute toxicities and long-term effects, particularly when administered to young children. These factors sometimes present a dilemma as to the best approach to optimize the chance of cure, minimize toxicity, and respect quality of life. The purpose of this review is to discuss 'optimal' management of this complicated tumor. Since the tumor is relatively rare, requires highly specialized care, and important management questions remain to be answered, optimal management of rhabdomyosarcoma includes enrollment in clinical trials whenever possible. Appropriate management begins with establishing the correct pathologic diagnosis, histologic subtype, primary site, extent of disease (International Society of Pediatric Oncology [SIOP]-TNM-Union Internationale Contre le Cancer stage or Intergroup Rhabdomyosarcoma Study Group [IRSG] stage), and extent of resection (IRSG group). Cooperative groups throughout North America and Europe have defined risk-adapted treatment based on these factors; this treatment requires a coordinated management plan that includes surgery, chemotherapy, and usually radiotherapy. The surgical approach for rhabdomyosarcoma is to excise the primary tumor whenever possible without causing major functional or cosmetic deficits. Wide excision is difficult in some primary sites and can be complicated by the fact that the tumor grows in a locally infiltrative manner so that complete resection is often neither possible nor medically indicated. Incompletely resected tumors are generally treated with radiotherapy. The cooperative groups reduce the dose of radiation based on the response of the tumor to chemotherapy and delayed primary resection to differing degrees. Response-adjusted radiation administration may reduce the long-term effects of radiotherapy, such as bone growth arrest, muscle atrophy, bladder dysfunction, and induction of second malignant neoplasms; however, it may also be associated with an increased risk of tumor recurrence. All patients with rhabdomyosarcoma require chemotherapy. A backbone of vincristine and dactinomycin with either cyclophosphamide (VAC) or ifosfamide (IVA) has been established. Risk-adapted treatment involves reducing or eliminating the alklyating agent for patients with the most favorable disease characteristics. Clinical trials are ongoing to improve outcomes for higher risk patients; newer agents, such as topotecan or irinotecan, in combination with VAC or use of agents in novel ways are being investigated. Acute and long-term toxicities associated with these chemotherapy regimens include myelosuppression, febrile neutropenia, hepatopathy, infertility, and second malignant neoplasms. A 5-year survival rate >70% has been achieved in recent trials for patients with localized rhabdomyosarcoma. However, the outcome for patients who present with metastatic disease remains poor. In the future, risk-adapted classification of rhabdomyosarcoma will likely be based on biologic features, such as the presence of chromosomal translocations or specific gene expression profiles. It is hoped that newer therapies directed at specific molecular genetic defects will benefit all patients with rhabdomyosarcoma.

Revisiting the role of doxorubicin in the treatment of rhabdomyosarcoma: an up-front window study in newly diagnosed children with high-risk metastatic disease

PURPOSE

Many cooperative groups have reported on the chemo-sensitivity of rhabdomyosarcoma (RMS). Doxorubicin has been tested but remains a controversial treatment option. We report here the results of the up-front evaluation of the efficacy of doxorubicin in children and adolescents with high-risk metastatic RMS.

PATIENTS AND METHODS

Patients younger than 18 years of age (>6 months) with newly diagnosed, histologically confirmed high-risk metastatic RMS were required to have measurable disease, to have undergone no prior chemotherapy or radiation therapy and to have normal liver, renal and cardiac function before treatment. Doxorubicin was administered intravenously over 48h to a total dose of 60mg/m2. Two courses were given separated by a 21day interval. Response to therapy was assessed by diagnostic imaging after the second course. The study was designed as a two-stage procedure according to the multistep plan described by Fleming.

RESULTS

Twenty patients were eligible for analysis. Median age at diagnosis was 9.8 years (range from 2 to 16). Thirteen of the 20 patients treated in the first step responded to treatment, corresponding to an overall response to doxorubicin of 65% [95% confidence interval (CI), 44-85%]. The rates of CR and PR were 5% [95% CI, 0-14%] and 60% [95% CI, 39-81%], respectively. Four (20%) patients had progressive disease, corresponding to a progression rate of 20% [95% CI, 2-38%].

CONCLUSION

This window study provides the definitive demonstration of the efficacy of doxorubicin in untreated RMS. Given the inconclusive results obtained from previous studies using differing schedules chemotherapy incorporating doxorubicin, the next step should be a randomised study testing dose intensity in high-risk localised RMS. This issue is being addressed in a current European study (EpSSG RMS 2005).

Pediatric surgical oncology: management of rhabdomyosarcoma

A malignant tumor of striated muscle origin, Rhabdomyosarcoma (RMS) is a childhood tumor that has benefited from 30 years of multimodality therapeutic trials culminating in a greater than 70% overall current 5-year survival. Prognosis for RMS is dependent on anatomic primary tumor site, age, completeness of resection, presence and number of metastatic sites, histology and biology of the tumor cells. Multimodality treatment is based on risk stratification according to pretreatment stage, postoperative group, histology and site. Therefore, pretreatment staging is vital for assessment and is dependent on primary tumor site, size, regional lymph node status, and presence of metastases. Unique to RMS is the concept of postoperative clinical grouping that assesses the completeness of disease resection and takes into account lymph node evaluation both at the regional and metastatic basins. At all sites, if operative resection of all disease is accomplished, including microscopic disease, survival is improved. Therefore, the surgeon plays a vital role in determining risk stratification for treatment and local control of the primary tumor for RMS.

Two consecutive phase II window trials of irinotecan alone or in combination with vincristine for the treatment of metastatic rhabdomyosarcoma: the Children's Oncology Group

PURPOSE

To estimate the antitumor activity and toxicity of irinotecan alone and in combination with vincristine when administered as window therapy and in combination with standard chemotherapy in pediatric patients with newly diagnosed metastatic rhabdomyosarcoma.

PATIENTS AND METHODS

Nineteen patients younger than age 21 years with newly diagnosed metastatic rhabdomyosarcoma or undifferentiated sarcoma received window therapy with two cycles of irinotecan (20 mg/m2 daily for 5 days, repeated for 2 weeks) and 50 patients received window therapy with vincristine 1.5 mg/m2 (weeks 0, 1, 3, and 4) and two cycles of irinotecan (20 mg/m2 daily for 5 days, repeated for 2 weeks). Patients who achieved a partial response (PR) or complete response (CR) received these agents alternating with vincristine (V; 1.5/mg/m2), dactinomycin (A; 1.5 mg/m2), and cyclophosphamide (C; 2.2 g/m2) during weeks 6 through 41. Nonresponders were treated with VAC alone. Radiotherapy was administered to sites of disease at weeks 15 to 21.

RESULTS

The window response rate (PR/CR) for patients who received irinotecan was 42% (95% CI, 38% to 80%) but the high progressive disease (PD) rate of 32% (95% CI, 11% to 52%) prompted closure of the trial. The window CR/PR rate for patients who received vincristine and irinotecan was 70% (95% CI, 57% to 83%), and the PD rate was only 8%. GI toxicities (abdominal pain, diarrhea, dehydration) were the most common adverse effects associated with the administration of irinotecan.

CONCLUSION

The combination of vincristine and irinotecan is highly active in metastatic rhabdomyosarcoma. The different mechanism of action and nonoverlapping toxicity profile with VAC makes this combination an attractive candidate for further testing in intermediate risk patients with rhabdomyosarcoma.

Orbital metastasis in patients with rhabdomyosarcoma: case series and review of the literature

We present 3 cases of children who developed recurrent rhabdomyosarcoma with metastases to the orbit and review the medical literature. Eight additional cases have previously been reported. Alveolar rhabdomyosarcoma was diagnosed in 7 cases. All 11 patients had stage 3 or 4 tumors at diagnosis, but none had orbital involvement initially. The mechanism of orbital recurrence is hematogenous in nature. Ten of the patients died; 7 of them succumbed with progressive disease within 6 months of the orbital recurrence.

Pooled analysis of phase II window studies in children with contemporary high-risk metastatic rhabdomyosarcoma: a report from the Soft Tissue Sarcoma Committee of the Children's Oncology Group

PURPOSE

The Soft Tissue Sarcoma Committee of the Children's Oncology Group has conducted five upfront window trials in patients with newly diagnosed metastatic rhabdomyosarcoma to identify promising new treatment agents.

PATIENTS AND METHODS

This pooled analysis identified a total of 420 patients (115 from Intergroup Rhabdomyosarcoma Study III [IRS-III] and 305 from the five window trials). We assessed window therapy response rate, failure-free survival (FFS), and overall survival (OS).

RESULTS

Response rates (complete + partial response) assessed at week 6 of window therapy ranged from 41% to 55% and did not predict FFS (P = .073) or OS (P = .31). FFS was influenced by trial (P = .048); patients enrolled onto IRS-III and the ifosfamide/etoposide and ifosfamide/doxorubicin trials fared best. When grouped and compared with topoisomerase I poison trials, ifosfamide/topoisomerase II inhibitor trials had superior FFS (P = .013). However, there was no difference in survival.

CONCLUSION

Upfront phase II window trials can efficiently provide robust estimates of activity for new agents and combinations in newly diagnosed patients with high-risk rhabdomyosarcoma. Our data indicate that, for some phase II window trials, the risk of treatment failure may be increased but that the trend towards lower survival for some of the window trials compared with IRS-III is not statistically significant. Window nonresponders did not suffer worse FFS or OS than patients who responded to window therapy. Finally, these results provide a rationale for incorporating ifosfamide, etoposide, doxorubicin, and topoisomerase I poisons in future trials of high-risk metastatic rhabdomyosarcoma.

Current chemotherapeutic strategies for rhabdomyosarcoma

Rhabdomyosarcoma is a typical tumor of childhood and adolescence. Over the years there has been a gradual but important improvement in survival for patients with this tumor, despite its high grade of malignancy. These results are due to multidisciplinary treatment approaches including surgery, radiotherapy and especially chemotherapy. Rhabdomyosarcoma is a highly chemosensitive neoplasm, and the role of this therapeutic approach has also been clearly demonstrated in the adjuvant setting. This review covers current concepts on chemotherapy for rhabdomyosarcoma, with an overview of the results of the main clinical trials conducted over recent years and considerations of possible strategies for the near future. Recommendations for adult patients with rhabdomyosarcoma are also discussed, suggesting that these patients should be treated according to pediatric guidelines.

Childhood rhabdomyosarcoma

A malignant tumor of striated muscle origin, Rhabdomyosarcoma (RMS) is a childhood tumor that has benefited from nearly 30 years of multimodality therapy culminating in a greater than 70% overall current 5-year survival. Prognosis for RMS is dependent on anatomic primary tumor site, age, completeness of resection, presence and number of metastatic sites, histology, and biology of the tumor cells. Multimodality treatment is based on risk stratification according to pretreatment stage, postoperative group, histology, and site. Therefore, pretreatment staging is vital for assessment and is dependent on primary tumor site, size, regional lymph node status, and presence of metastases. Unique to RMS is the concept of postoperative clinical grouping that assesses the completeness of disease resection and takes into account lymph node evaluation both at the regional and metastatic basins. At all sites, if operative resection of all disease is accomplished, including microscopic disease, survival is improved. Therefore, the surgeon plays a vital role in determining risk stratification for treatment and local control of the primary tumor for RMS. The current state of the art treatment is based on treatment protocols developed by the Soft Tissue Sarcoma Committee of the Children's Oncology Group.

Rhabdomyosarcoma: new windows of opportunity

Rhabdomyosarcoma is a highly malignant, small blue cell tumor characterized by muscle differentiation. With modern treatment, more than 70% of children and adolescents with this disease are cured. Adequate biopsy to obtain sufficient tissue for accurate diagnosis and molecular characterization is critical. Patients must be assessed for tumor extent; the Intergroup Rhabdomyosarcoma Study (IRS) clinical group and Staging system is universally applied in North America. Multidisciplinary therapy is necessary to maximize cure rates. Local control relies on complete surgical excision when possible; those whose tumors are not completely excised and those with alveolar histology tumors require local irradiation to maximize local control. In North America, vincristine (Oncovin); Eli Lilly and Company, Indianapolis, http://www.lilly.com), dactinomycin (Cosmegen); Merck & Co., Inc., Whitehouse Station, NJ, http://www.merck.com), and cyclophosphamide are the standard chemotherapy agents. The IRS has used therapeutic window studies to confirm the predictive nature of preclinical xenograft models and to identify several new single agents and combinations of agents with activity in high-risk patient groups. Despite these efforts, the outcome for these high-risk patients remains poor. The next generation of Children's Oncology Group studies will evaluate the efficacy of topoisomerase-I inhibitors and dose-compression therapy approaches. New advances in molecular characterization of tumors, including gene-expression analysis, may identify new therapeutic targets that can be exploited by expanded preclinical drug discovery efforts, and hold the promise of revolutionizing risk-based therapies.

Effectiveness of chemotherapy in rhabdomyosarcoma: example of orbital primary

The survival of patients with rhabdomyosarcoma has been progressively improved with successive protocols due to the development of multidisciplinary management and the data accumulated by international groups. Orbital rhabdomyosarcoma represents 10% of all cases and affects young children (median age: 6.8 years). It is a chemosensitive and radiosensitive tumour. Chemotherapy is designed to decrease the indications for local therapy (mainly radiotherapy) responsible for a high rate of sequelae (cosmetic, functional or secondary cancer). According to the International Society of Paediatric Oncology guidelines, local therapy is not indicated as first-line treatment in case of complete remission after chemotherapy. The 10-year survival of children with non-parameningeal orbital rhabdomyosarcoma is currently 87% and identical survivals are reported by the various collaborative groups despite the use of different treatments. Despite clinical trials demonstrating the efficacy of many types of chemotherapy (cisplatin, etoposide, doxorubicin, dacarbazine), the value of adding these drugs to combination chemotherapy comprising of an alkylating agent (cyclophosphamide or ifosfamide), vincristine and dactinomycin has not been formally demonstrated in terms of survival benefit for children with rhabdomyosarcoma. The authors review these various results and compare the current guidelines for the management of orbital rhabdomyosarcoma recommended by North American and European groups.

European intergroup studies (MMT4-89 and MMT4-91) on childhood metastatic rhabdomyosarcoma: final results and analysis of prognostic factors

PURPOSE

Final results are presented from two consecutive European studies for patients with metastatic rhabdomyosarcoma (RMS) to identify prognostic variables and determine the value of high-dose chemotherapy (HDCT) in complete remission.

PATIENTS AND METHODS

A total of 174 patients aged 3 months to 18 years participated. From 1989 to 1991, patients received four cycles of intensive multiagent chemotherapy. From 1991 to 1995, patients achieving complete remission received consolidation with HDCT. All received local therapy (surgery, radiation therapy) according to response.

RESULTS

At a median follow-up of 8 years, 5-year overall survival (OS) and event-free survival (EFS) for the whole group were 24% and 20%, respectively. No statistical difference was found between HDCT and standard chemotherapy (5-year OS, 36% v 27%; EFS 29% v 23%). Univariate analysis identified primary tumor in parameningeal, extremity, or other sites; age younger than 1 year and older than 10 years; bone or bone marrow metastases; multiple metastases; and multiple sites of metastases as unfavorable prognostic factors for OS and EFS. Multivariate analysis identified unfavorable site, bone or bone marrow involvement, and unfavorable age as independently unfavorable factors. Two subgroups were identified. Those with fewer than two unfavorable factors had 5-year EFS and OS of 40% and 47%, respectively. Patients with > or = two unfavorable factors had 5-year EFS and OS of 7.5% and 9%, respectively.

CONCLUSION

A minority of patients with metastatic RMS have better survival than overall results for this population suggest. Those in the highest risk group have such poor survival that they are candidates for first-line novel therapies. There is no evidence that consolidation with HDCT improves outcome.

The IVADo regimen?A pilot study with ifosfamide, vincristine, actinomycin D, and doxorubicin in children with metastatic soft tissue sarcoma

BACKGROUND

The role of doxorubicin (Doxo) as part of multidrug regimens used to treat children with soft tissue sarcoma (STS) is controversial. To evaluate the feasibility of combining Doxo with the well established ifosfamide, vincristine, and actinomycin D (IVA) regimen, the Italian STS Committee performed a pilot study on a series of children with metastatic STS.

METHODS

Between July 2002 and February 2004, 29 evaluable patients were enrolled in this study; 19 patients had rhabdomyosarcoma, 5 patients had peripheral neuroectodermal tumor, and 5 patients had other types of STS. The IVA-Doxo (IVADo) regimen included ifosfamide 3 g/m(2) on Days 1 and 2, vincristine 1.5 mg/m(2) on Day 1, actinomycin D 1.5 mg/m(2) on Day 1, and Doxo 30 mg/m(2) on Days 1 and 2. Three courses of IVADo were to be administered in the initial part of treatment and analyzed for toxicity and tumor response.

RESULTS

Overall, 92 cycles were delivered. Major regimen-related toxicity was myelosuppression, with Grade 4 neutropenia in 67% of cycles and fever and neutropenia in 37% of cycles. Nonhematologic toxicity included Grade 3-4 mucositis (6.5% of cycles), constipation (9.7%), and peripheral neuropathy (6.5%). Other manifestations of major toxicity were venoocclusive disease and seizures, which occurred in one patient each. All but 1 patient with a malignant schwannoma showed some degree of tumor volume reduction; however, considering only complete and partial remissions, the response rate was 76% (+/- 7.9%).

CONCLUSIONS

The intensive IVADo regimen was effective against pediatric STS with acceptable toxicity. This combination will be investigated in high-risk patients with rhabdomyosarcoma in a randomized trial launched by the European pediatric Soft tissue sarcoma Study Group.

Metastatic rhabdomyosarcoma: a retrospective review of patients treated at the hospital for sick children between 1989 and 1999

Children with metastatic rhabdomyosarcoma (RMS) continue to fare poorly (3-year survival 20-30%). Various therapies, including end-intensification with high-dose chemotherapy and stem cell support, have been used in an attempt to improve the outcome of these patients. The authors reviewed their clinical experience over a 10-year period to identify predictors of outcome in these patients. The authors reviewed the clinical characteristics, treatment, and outcome of all patients with metastatic RMS diagnosed and treated at the Hospital for Sick Children between 1989 and 1999. Kaplan-Meier curves were generated to compare survival and failure-free survival of different subgroups of patients. Differences between groups were analyzed using univariate analysis and the log-rank test. Seventeen patients with metastatic RMS were identified. Thirteen patients were treated with standard chemotherapy +/- radiotherapy and four received high-dose end-intensification therapy with stem cell support. The estimated 3-year overall survival (OS) and failure-free survival rates for all patients were 35% (95% CI 13-58) and 29% (95% CI 18-40), respectively. Patients with embryonal histology, metastases confined to the lung, and age younger than 10 years had a 3-year OS of 100%, compared with an OS of 0% for the remaining patients (P < 0.0006). The median follow-up for the five survivors was 5.5 years. The authors have identified a subset of children with metastatic RMS having embryonal histology, age less than 10 years, and only pulmonary metastases who have favorable survival outcomes when treated with chemotherapy with or without stem cell support.

Efficacy of topotecan and cyclophosphamide given in a phase II window trial in children with newly diagnosed metastatic rhabdomyosarcoma: a Children's Oncology Group study

PURPOSE

To determine the antitumor activity and toxicity of topotecan given immediately after cyclophosphamide as window therapy, then in combination with conventional agents in pediatric patients with newly diagnosed metastatic rhabdomyosarcoma (RMS).

PATIENTS AND METHODS

Sixty-one patients younger than 21 years with newly diagnosed metastatic RMS or undifferentiated sarcoma were assigned window therapy (weeks 0 to 6) with topotecan (0.75 mg/m(2) daily x 5 every 21 days) immediately after cyclophosphamide (250 mg/m(2) daily x 5 every 21 days; TC). We continued to give these agents in combination with vincristine (VTC) to patients who showed objective improvement, partial response (PR), or complete response (CR) to TC and alternated courses of VTC with vincristine, dactinomycin and cyclophosphamide (VAC) during weeks 6 to 41 (VTC/VAC). Those who showed no response or progressive disease after TC received only VAC. All patients received radiotherapy to sites of unresected disease (weeks 15 to 21).

RESULTS

The overall response rate (CR + PR) to TC was 47% (95% CI, 35% to 60%). Tumor size < or = 5 cm was associated with early response. Myelosuppression was the primary toxicity to TC. Overall 3-year disease-free survival and survival were estimated to be 10% (95% CI, 2% to 19%) and 20% (95% CI, 8% to 32%), respectively. Toxicity profiles for patients who received VTC/VAC or VAC alone were comparable.

CONCLUSION

Topotecan after cyclophosphamide is a combination that is active against newly diagnosed RMS, with an acceptable toxicity profile. Disease-free survival and overall survival, however, remain disappointing for children with metastatic RMS at diagnosis.

Pediatric soft-tissue tumors

Soft-tissue tumors in children (<18 years) are a heterogeneous group of lesions. Masses may be asymptomatic or associated with pain or discomfort. Although most lesions are benign, developing an appropriate differential diagnosis requires knowledge of the clinical and radiographic characteristics of tumors and tumorlike conditions in children. A thorough history and physical examination, followed by appropriate imaging studies, when indicated, can establish a correct diagnosis and help determine appropriate treatment recommendations.

Pediatric genitourinary tumors

Advances continue to be made in the evaluation and treatment of genitourinary tumors in children. Continued research on the cellular, molecular, and genetic process in tumorigenesis is rapidly evolving. We review the 2002 literature on pediatric genitourinary tumors. Molecular and cellular biology research continues to identify markers that may predict a worse prognosis. This identification will allow a more tailored approach with intensified treatment of aggressive tumors.

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.