What is new in rhabdomyosarcoma management in children?

Laparoscopic management of Rhabdomyosarcoma of common Bile duct, Case report

INTRODUCTION

Embryonal Rhabdomyosarcoma (ERMS) is a malignant soft tissue musculoskeletal tumor which constitutes about 0.06% of all malignancies affecting children. Biliary tract ERMS is still rare, though it is considered the most common cause of malignant obstructive jaundice in children.

CASE PRESENTATION

A report of a 2-year-old boy, who was presented with recurrent episodes of scleral icterus of three months duration, is added to the related literature. His labs went with obstructive jaundice and the radiological investigations were consistent with a diagnosis of choledochal cyst. The found mass was suspected to be an ERMS of common bile duct and turned out to be so by the histopathology. He was managed totally by laparoscope, both excision and hepaticojejunostomy reconstruction, which is an extremely uncommon entity.

CONCLUSION

Common Bile Duct Rhabdomyosarcoma is rare and diagnosis at this anatomical site is difficult. Our case highlights the feasibility of laparoscopic resection and hepaticojejunostomy reconstruction with very good results at 16-month follow up and parents' gratitude as well.

Oral and Dental Abnormalities Caused by a Pediatric Rhabdomyosarcoma Tumor Treatment: A Clinical Case Report

Rhabdomyosarcoma is one of the most common soft-tissue sarcomas in children. The therapy for this condition has evolved significantly over recent decades, as has survival rates. Nevertheless, multiagent chemotherapy, radiation therapy, surgical resection or a combination of these modalities still have to be performed. This case report presents a 16-year-old boy with oral and dental effects after rhabdomyosarcoma treatment, diagnosed at the age of 4 years old. This report highlights the key role of dentists in the clinical management of rhabdomyosarcoma cases before, during and after treatment, and its potential side effects.

The role of solute carrier (SLC) transporters in actinomycin D pharmacokinetics in paediatric cancer patients

BACKGROUND

Actinomycin D is used for treatment of paediatric cancers; however, a large inter-patient pharmacokinetic (PK) variability and hepatotoxicity are significant limitations to its use and warrant further investigation. Elimination of actinomycin D may be mediated by transporters, as the drug does not seem to undergo significant metabolism. We investigated the role of solute carrier (SLC) transporters in actinomycin D PK.

METHODS

Fourteen key SLCs were screened through probe substrate uptake inhibition by actinomycin D in HEK293 cells. Uptake of actinomycin D was further studied in candidate SLCs by measuring intracellular actinomycin D using a validated LCMS assay. Pharmacogenetic analysis was conducted for 60 patients (Clinical trial: NCT00900354), who were genotyped for SNPs for OAT4 and PEPT2.

RESULTS

OAT4, OCT2, OCT3 and PEPT2 showed significantly lower probe substrate uptake (mean ± SD 75.0 ± 3.5% (p < 0.0001), 74.8 ± 11.2% (p = 0.001), 81.2 ± 14.0% (p = 0.0083) and 70.7 ± 5.7% (p = 0.0188)) compared to that of control. Intracellular accumulation of actinomycin D was greater compared to vector control in OAT4-transfected cells by 1.5- and 1.4-fold at 10 min (p = 0.01) and 20 min (p = 0.03), and in PEPT2-transfected cells by 1.5- and 1.7-fold at 10 min (p = 0.047) and 20 min (p = 0.043), respectively. Subsequent clinical study did not find a significant association between OAT4 rs11231809 and PEPT2 rs2257212 genotypes, and actinomycin D PK parameters such as clearance (CL) and volume of distribution (V_d).

CONCLUSION

Transport of actinomycin D was mediated by OAT4 and PEPT2 in vitro. There was a lack of clinical significance of OAT4 and PEPT2 genotypes as predictors of actinomycin D disposition in paediatric cancer patients.

Management of pediatric head and neck rhabdomyosarcoma: A case-series of 36 patients

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in the pediatric population. In 35% of cases, RMS develops in the head and neck (H&N) region, and only combined therapy is recognized as a curative treatment. However, recent advances in skull base and reconstructive surgery, along with microsurgery and endoscopic surgery, have strengthened the role of surgery as an important part of RMS treatment. In the present study, 36 pediatric RMS cases (24 males and 12 females) were analyzed after surgical treatment. The average age at diagnosis was 7 years. In total, 67% of tumors were localized in the parameningeal region. Alveolar RMS was the most common histopathological type. A total of 16 patients were treated due to disease recurrence or a previous non-radical surgical procedure, while 19 cases had inductive chemotherapy and/or radiotherapy preceding surgical treatment due to locally advanced disease. In 1 case, only diagnostic biopsy was performed. It is recommended that the management of H&N RMS is interdisciplinary from the beginning. Extensive surgical dissection in the H&N region for RMS may result in severe cosmetic defects and functional impairment; thus, these risks should be considered during treatment planning, and the surgical approach should be based on the individual characteristics of each patient.

Enzastaurin inhibits ABCB1-mediated drug efflux independently of effects on protein kinase C signalling and the cellular p53 status

The PKCβ inhibitor enzastaurin was tested in parental neuroblastoma and rhabdomyosarcoma cell lines, their vincristine-resistant sub-lines, primary neuroblastoma cells, ABCB1-transduced, ABCG2-transduced, and p53-depleted cells. Enzastaurin IC₅₀s ranged from 3.3 to 9.5 μM in cell lines and primary cells independently of the ABCB1, ABCG2, or p53 status. Enzastaurin 0.3125 μM interfered with ABCB1-mediated drug transport. PKCα and PKCβ may phosphorylate and activate ABCB1 under the control of p53. However, enzastaurin exerted similar effects on ABCB1 in the presence or absence of functional p53. Also, enzastaurin inhibited PKC signalling only in concentrations ≥ 1.25 μM. The investigated cell lines did not express PKCβ. PKCα depletion reduced PKC signalling but did not affect ABCB1 activity. Intracellular levels of the fluorescent ABCB1 substrate rhodamine 123 rapidly decreased after wash-out of extracellular enzastaurin, and enzastaurin induced ABCB1 ATPase activity resembling the ABCB1 substrate verapamil. Computational docking experiments detected a direct interaction of enzastaurin and ABCB1. These data suggest that enzastaurin directly interferes with ABCB1 function. Enzastaurin further inhibited ABCG2-mediated drug transport but by a different mechanism since it reduced ABCG2 ATPase activity. These findings are important for the further development of therapies combining enzastaurin with ABC transporter substrates.

Breast relapse after metastatic alveolar rhabdomyosarcoma: Is it an incurable entity?

Metastatic breast disease is a very rare condition in children. Rhabdomyosarcoma (RMS) is the most common solid primary tumor in children, but only a few cases of breast metastases have been described. We present the case of a young female with a primary pelvic metastatic alveolar RMS, which metastasized to the breast twice and achieved prolonged complete remission with a multimodal approach.

Focusing on organ preservation and function: paradigm shifts in the treatment of pediatric genitourinary rhabdomyosarcoma

OBJECTIVE

Pediatric genitourinary rhabdomyosarcoma (RMS) accounts for 25 % of all pediatric soft tissue sarcomas. The treatment of these tumors has shifted over time from debilitating radical exenteration to organ-sparing techniques using multimodal therapy. Our review aims to summarize recent relevant literature regarding the current treatment practices of pediatric genitourinary RMS and how these practices have shifted over time.

METHODS

PubMed database search was utilized to identify relevant literature from 1997 to 2015 relating to the treatment of pediatric genitourinary RMS with emphasis on organ preservation and maintaining organ function.

RESULTS

A total of 31 articles from 1997 through 2015 were identified relating to current management concepts in pediatric genitourinary sarcomas. Relevant articles were reviewed in detail and discussed.

CONCLUSION

The treatment of pediatric genitourinary RMS has shifted from debilitating pelvic exenteration to a multimodal treatment approach involving surgery, chemotherapy, and radiation therapy in an effort to preserve genitourinary organs and reduce treatment morbidity. Continued research is required to improve post-treatment organ function. Further studies utilizing objective urodynamic evaluation are necessary to better characterize bladder function after treatment for RMS. Exciting recent developments in RMS research of fusion proteins that induce cell transformation and inhibit apoptosis and myogenic differentiation may result in future management changes to treatment protocols.

Pediatric sinonasal rhabdomyosarcoma: A case report

Pediatric sinonasal rhabdomyosarcoma (PSR) is a rare condition, with a limited number of previously reported cases. It is an aggressive malignancy associated with poor outcomes, and no consensus has been reached on the optimal therapeutic strategy. The present study reported the case of embryonal PSR in a 2-year old girl, presenting with unilateral nasal obstruction and a polypoid mass protruding from the left nasal cavity. The pediatric patient was initially treated with surgical resection, followed by adjuvant chemotherapy containing vincristine (1.5 mg/m², weekly) and actinomycin-D (1.5 mg/m², three times weekly). On the 10th month of follow-up, tumor recurrence was detected and a salvage surgery was performed, while the same chemotherapy regimen was resumed. Following the first cycle of chemotherapy, the patient developed a fungal bronchopneumonia and succumbed due to disease progression, acute respiratory distress syndrome and septic shock 12 months after diagnosis.

Recent advances in understanding and managing rhabdomyosarcoma

Rhabdomyosarcoma is the most common childhood soft tissue sarcoma and the fourth most common pediatric solid tumor. For most patients, treatment consists of a multimodality approach, including chemotherapy, surgery, and/or radiotherapy. To guide treatment, patients with rhabdomyosarcoma are risk stratified based on a number of factors. These factors include clinical group, which depends largely on the extent of resection and nodal involvement, and stage, which takes into account tumor size, invasion, nodal involvement, and disease site. Histology of the tumor and age at diagnosis are also factored into risk stratification. Recent advances in understanding the biology of the disease have allowed for the further sub-classification of rhabdomyosarcoma. In addition, elucidation of additional clinical features associated with poor prognosis has allowed for better understanding of risk and provides more clarity regarding those patients who require more intensive therapy. Many areas of active investigation are ongoing, including the following: further delineation of the biological underpinnings of the various disease subtypes with the possibility of molecularly targeted therapy; a better understanding of clinical risk factors, including the evaluation and management of potentially involved lymph nodes; determination of the appropriate role of post-treatment imaging and assessment of response to therapy; and incorporation of advanced radiotherapeutic techniques, including conformal intensity-modulated photon and proton therapy.

Rhabdomyosarcoma of the head and neck in children

Rhabdomyosarcoma (RMS) is the most frequent soft tissue sarcoma in children. It is localized in the head and neck region in 40% of cases. Treatment of RMS is complex, including multi-drug chemotherapy, radiotherapy and surgery. The progress that has been accomplished in oncology in recent decades significantly improved outcomes. The 5-year survival rate raised from 25% in 1970 to 73% in 2001, according to IRS-IV data. The outcome is influenced by primary tumor localization, clinical staging, histological tumor type and age at the moment of diagnosis. The relatively rare incidence of these tumors resulted in difficulties in creating more standardized therapeutic protocols. Comparison of outcomes in large patients groups led to an increase in the number of patients with complete remission. Although survival rates of RMS patients have improved, searching for new therapeutic modalities and substances is still essential to improve outcomes in cases of more advanced stages and unfavorable tumor localizations.

Nonurological malignancies in children

Context:

Nonurological malignancies in children include a wide variety of tumors. These tumors include primary tumors of the liver, thyroid, lung, gastrointestinal tract (GIT), and adrenals; soft tissue sarcomas (STSs) like rhabdomyosarcoma (RMS) and non-RMS; and finally extragonadal germ cell tumors (GCT).

Aims:

This article aims at describing the current thinking in the management of these childhood solid tumors. This is critical in view of the recent advances in the elucidation of the molecular, genetic, and biologic behavior of these tumors and how these factors are getting integrated not only in the staging but also in developing a risk-based approach towards the management of these tumors.

Materials and Methods:

Reference was made to recently published literature from the leading pediatric cancer centers of the world to make a sense of things of the most current thinking in this rapidly expanding field. This will provide surgeons and physicians taking care of these children with a working knowledge in this somewhat challenging field.

Conclusions:

Treatment results vary from center to center depending on access to resources and following different management protocols. Results have improved for these tumors with the advent of newer chemotherapeutic agents, novel delivery methods of radiation therapy (RT), and improvement in surgical technique. Due to the limited number of patients presenting with these tumors, national and international collaboration of data is critical for all and beneficial to individual treatment centers. This has resulted in better results in the past and will definitely result in still better results in the future.