Surgical management of paratesticular rhabdomyosarcoma: A consensus opinion from the Children's Oncology Group, European paediatric Soft tissue sarcoma Study Group, and the Cooperative Weichteilsarkom Studiengruppe

Minimally invasive and robotic-assisted approaches applied to pediatric surgical oncology

The management of pediatric tumors is complex, with surgery, chemotherapy, and radiotherapy being cornerstones in their treatment. Tumor removal is increasingly performed by a minimally invasive approach, which allows for quicker postoperative recovery and less postoperative pain. The goal of this report is to give an overview of minimally invasive surgical approaches for common pediatric tumors, with a focus on technical considerations and postoperative outcomes.

Lymph Node Staging and Treatment in Pediatric Patients With Soft Tissue Sarcomas: A Consensus Opinion From the Children's Oncology Group, European paediatric Soft Tissue Sarcoma Study Group, and the Cooperative Weichteilsarkom Studiengruppe

Accurate staging of nodal involvement in pediatric sarcoma patients is important to determine correct systemic and local therapy, with the goal to reduce subsequent recurrences. However, differences in lymph node staging strategies, definitions, and treatment protocols between the Children's Oncology Group (COG), European paediatric Soft tissue sarcoma Study Group (EpSSG), and the Cooperative Weichteilsarkom Studiengruppe (CWS) complicate comparisons. In this article, we aim to establish internationally recognized recommendations for lymph node assessment and treatment of children and adolescents diagnosed with rhabdomyosarcoma (RMS) and non-rhabdomyosarcoma soft tissue sarcoma (NRSTS) according to the Consensus Conference Standard Operating Procedure methodology.

Rhabdomyosarcoma Surgical Update

Rhabdomyosarcoma (RMS) tumors arise from mesenchymal tissue and represent half of pediatric sarcomas, which in turn make up 7% of pediatric tumors. Advances in local control therapy of RMS have improved outcomes after surgical resection of the primary tumor, either before or after induction chemotherapy, even in the setting of metastatic disease. The utilization of diagnostic core needle and sentinel node biopsy techniques for lymph node staging are becoming more widely used. Over the past several years, refinement of prognostic factors with adoption of fusion status instead of histology, and optimized risk stratification schemas have been developed to assure appropriate therapy. There have been efforts between North American and European surgical oncology cooperative groups to standardize the care we provide, and yet there are still some philosophical differences to overcome.

Unplanned Excision in Soft Tissue Sarcoma: Current Knowledge and Remaining Gaps

Soft tissue sarcoma (STS) is a rare and heterogeneous disease, which can result in surgeons not considering STS as a differential diagnosis when they encounter a lump. However, unplanned excision (UE) often occurs in nonspecialized sarcoma centers. Before re-excision (RE) after UE, radiological examinations such as magnetic resonance imaging (MRI) should be performed to determine the surgical margin and conduct a pathological evaluation of the UE. However, differentiating between residual tumor and postsurgical changes remains challenging because of the presence of postoperative edema, hematoma, and seroma on MRI. Propensity score matching analysis showed that patients with STS who underwent RE after UE did not have higher mortality or local recurrence rates than those who underwent planned excision (PE), while RE often requires reconstruction procedures. From the patient's perspective, one operation (PE) is better than two (UE and RE) because it reduces hospital stays and time away from work. Continuous education about STS is necessary for all surgeons to reduce the incidence of UE.

How Many Lymph Nodes are Enough in Paratesticular Rhabdomyosarcoma?

BACKGROUND

Treatment strategies for paratesticular rhabdomyosarcoma (PT RMS) are based on stage, which requires accurate lymph node (LN) evaluation. Previous methodology for determining quantity of LN for negative nodal status is based on LN positivity rates, without accounting for the relationship between LNs or amongst patients. This study aims to quantify the chance of missing involved LNs based on LN yield (LNY) using a previously established methodology in comparison to current recommendations.

METHODS

Using the National Cancer Database, patients with a diagnosis of PT RMS were queried from 2004 to 2018. Patients >10 years and those ≤10 years with cN1 disease were included, based on COG guidelines for who should undergo retroperitoneal LN sampling (RPLNS). The beta-binomial model was used to calculate the rate of false negative RPLNS and identified the LNY threshold to reduce the risk of a missing an involved LN node to <10 %.

RESULTS

Sixty-two patients were included for analysis over the study period. Median LNY was 17 (IQR 9-28.75), and the median number of involved LNs was 2.5 (IQR 2-5). The median LN density was 0.27 (IQR 0.10-0.34). Application of the beta-binomial model identified that a LNY of 26 LNs corresponds to a <10 % chance of missing occult disease (Fig. 3).

CONCLUSION

Previous models estimate that sampling of 7-12 LN is adequate for accurate staging. However, the beta binomial model quantifies sampling at least 26 LNs to reduce the chance of missing occult metastatic disease to <10 % in the majority of patients. Surgeons should consider this false negative rate during RPLNS for patients with PT RMS.

LEVEL OF EVIDENCE

III.

Importance of Adequate Surgical Local Control in Fusion-Negative Para-Testicular Rhabdomyosarcoma: Data From the Cooperative Weichteilsarkom Studiengruppe Trials (CWS-96 and CWS-2002P) and the European Soft Tissue Sarcoma Registry (SoTiSaR)

BACKGROUND

This study aimed to assess the impact that the quality of primary and subsequent surgeries has on the survival of patients with para-testicular rhabdomyosarcoma (PTRMS).

METHODS

Patients with localized (IRS I-III) and metastatic (IRS IV) PTRMS were enrolled in the two Cooperative Weichteilsarkom Studiengruppe (CWS) trials (CWS-96, CWS-2002P) and the Soft Tissue Sarcoma Registry (SoTiSaR).

RESULTS

Among 196 patients (median age, 8.4 years), 106 (54.1%) had primary complete resection. Image-defined lymph node (LN) disease was detected in 21 (11.5%) patients in the localized cohort and 12 (92.3%) patients in the metastatic cohort. The 5-year event-free survival (EFS) and overall survival (OS) were respectively 87.3% and 94.0% for the patients with localized PTRMS and 46.2% and 42.2% for the patients with metastatic PTRMS. Protocol violations during the primary surgery (PV-PS) were observed in 70 (42%) of the IRS I-III patients. This resulted in higher rates of R1/R2 resections (n = 53 [76%] vs n = 20 [21%]; p < 0.001) with a need for pretreatment re-excision (PRE) (n = 50 [83%] vs n = 10 [17%]; p < 0.001) compared with the patients undergoing correct primary surgery. Protocol violations during PRE occurred for 13 (20%) patients. Although PV-PS did not influence the 5-year EFS or OS in the localized PTRMS cohort, the unadjusted log-rank test showed that R status after PRE is a prognostic factor for 5-year OS (R1 vs R0 [81.8% vs 97.6%]; p = 0.02).

CONCLUSIONS

The quality of surgical local control in PTRMS is unsatisfactory. Emphasis should be placed on evaluating the resection status after PRE in further clinical trials.

A Rare Case of Paratesticular Sarcoma: A Case Report

Paratesticular rhabdomyosarcoma (PRMS) is a rare and aggressive soft tissue tumour that can mimic testicular sarcoma on initial imaging studies, leading to diagnostic ambiguity and treatment delays. In this case report, we present the case of a 45-year-old male who came to our department and was evaluated under ultrasound imaging along with colour Doppler. The patient underwent further examination under a multi-slice CT machine, which provided additional information, and finally underwent a 1.5T MRI scan. After a provisional diagnosis was made, the patient underwent surgery, and the specimen was sent for histopathology and relevant immunohistopathological markers. This case underscores the diagnostic challenges posed by PRMS and emphasizes the need for a multidisciplinary approach involving radiologists, oncologists, and surgeons for timely diagnosis and optimal management. We discuss the clinical implications, imaging characteristics, differential diagnosis, and therapeutic considerations for PRMS to guide clinicians in similar diagnostic dilemmas.

Children's Oncology Group's 2023 blueprint for research: Surgery

Surgery plays a crucial role in the treatment of children with solid malignancies. A well-conducted operation is often essential for cure. Collaboration with the primary care team is important for determining if and when surgery should be performed, and if performed, an operation must be done in accordance with well-established standards. The long-term consequences of surgery also need to be considered. Indications and objectives for a procedure vary. Providing education and developing and analyzing new research protocols that include aims relevant to surgery are key objectives of the Surgery Discipline of the Children's Oncology Group. The critical evaluation of emerging technologies to ensure safe, effective procedures is another key objective. Through research, education, and advancing technologies, the role of the pediatric surgeon in the multidisciplinary care of children with solid malignancies will continue to evolve.

Frontline and Relapsed Rhabdomyosarcoma (FaR-RMS) Clinical Trial: A Report from the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG)

The Frontline and Relapsed Rhabdomyosarcoma (FaR-RMS) clinical trial is an overarching, multinational study for children and adults with rhabdomyosarcoma (RMS). The trial, developed by the European Soft Tissue Sarcoma Study Group (EpSSG), incorporates multiple different research questions within a multistage design with a focus on (i) novel regimens for poor prognostic subgroups, (ii) optimal duration of maintenance chemotherapy, and (iii) optimal use of radiotherapy for local control and widespread metastatic disease. Additional sub-studies focusing on biological risk stratification, use of imaging modalities, including [18F]FDG PET-CT and diffusion-weighted MRI imaging (DWI) as prognostic markers, and impact of therapy on quality of life are described. This paper forms part of a Special Issue on rhabdomyosarcoma and outlines the study background, rationale for randomisations and sub-studies, design, and plans for utilisation and dissemination of results.

Review on Lymph Node Metastases, Sentinel Lymph Node Biopsy, and Lymphadenectomy in Sarcoma

Soft tissue sarcomas (STS) originating from connective tissue rarely affect the lymph nodes. However, involvement of lymph nodes in STS is an important aspect of prognosis and treatment. Currently, there is no consensus on the diagnosis and management of lymph node metastases in STS. The key risk factor for nodal involvement is the histological subtype of sarcoma. Radiological and pathological evaluation seems to be the most effective method of assessing lymph nodes in these neoplasms. Thus, sentinel lymph node biopsy (SLNB), which has been shown to be valuable in the management of melanoma or breast cancer, may also be a beneficial diagnostic option in some high-risk STS subtypes. This review summarizes data on the risk factors and clinical characteristics of lymph node involvement in STS. Possible management and therapeutic options are also discussed.

Adult Para Testicular Spindle Cell Rhabdomyosarcoma: A Case Report From Pakistan

Para testicular or intra-scrotal Rhabdomyosarcomas (RMS) are rare. The spindle cell variant of rhabdomyosarcoma is the least common variant among embryonal subtypes. They are mostly seen in childhood but rarely reported in adults. We present a case of a 56-year-old man who presented with a three-year history of painless left inguinoscrotal swelling, which he initially ignored and misinterpreted as an Inguinal hernia but later sought medical help upon a progressive increase in the size of the swelling. Clinically and radiologically, there was sparing of the left testis and spermatic cord with normal testicular tumor markers and no evidence of lymphadenopathy or metastasis. Surgical exploration was performed with complete excision of the mass, followed by histopathology and immunocytochemistry, confirming the diagnosis of spindle cell rhabdomyosarcoma. Prompt recognition, early diagnosis, and appropriate surgical treatment are the hallmarks of management. Regular and strict follow-up is needed due to the rarity of diagnosis.

Treatment results of Para-Testicular Rhabdomyosarcoma (PT-RMS) using radiation as an alternative to retro-peritoneal nodal dissection: A single Institution experience

BACKGROUND

Para-testicular Rhabdomyosarcoma (PT-RMS) has a favorable treatment outcome adopting multidisciplinary management; resection, namely high inguinal orchiectomy ± retro-peritoneal lymph node dissection (RPLND) followed by standard or intensive chemotherapy ± adjuvant radiation therapy.

PATIENTS AND METHODS

This is a retrospective study including all patients with pathologically proven PT-RMS, presented to the National Cancer Institute, Cairo University, during the period from 2005 to 2020. Endpoints included overall survival, disease free survival and patterns of failure of different treatment modalities.

RESULTS

Forty one patients were identified. Median age in our cohort was 15 years (range: 2-54 years). After a median follow up of 26 months (range, 3-75 months) ,two and five years OS were 100% and 91.7% respectively and median survival was not reached. Patients who underwent retro-peritoneal nodal dissection had a 5-year DFS rate of 100% versus 73% for those who received radiation to para-aortic nodes (p = 0.185). Limitations include retrospective nature and deviation from COG protocol.

CONCLUSIONS

This study shows promising results suggesting that less aggressive local treatment modalities including radiation to para-aortic chain could be an option in PT-RMS, given the excellent results of this subtype. However further validation in a prospective study is warranted.

Rhabdomyosarcoma: Current Therapy, Challenges, and Future Approaches to Treatment Strategies

Rhabdomyosarcoma is a rare cancer arising in skeletal muscle that typically impacts children and young adults. It is a worldwide challenge in child health as treatment outcomes for metastatic and recurrent disease still pose a major concern for both basic and clinical scientists. The treatment strategies for rhabdomyosarcoma include multi-agent chemotherapies after surgical resection with or without ionization radiotherapy. In this comprehensive review, we first provide a detailed clinical understanding of rhabdomyosarcoma including its classification and subtypes, diagnosis, and treatment strategies. Later, we focus on chemotherapy strategies for this childhood sarcoma and discuss the impact of three mechanisms that are involved in the chemotherapy response including apoptosis, macro-autophagy, and the unfolded protein response. Finally, we discuss in vivo mouse and zebrafish models and in vitro three-dimensional bioengineering models of rhabdomyosarcoma to screen future therapeutic approaches and promote muscle regeneration.

Critical elements of pediatric rhabdomyosarcoma surgery

Rhabdomyosarcoma (RMS), the most common soft tissue sarcoma in children, requires multimodal therapy which is determined by risk group stratification. Local control may be achieved by surgical resection, radiation, or both. Resection may occur upfront or following induction chemotherapy as a delayed primary excision. An R1 resection may allow a reduction in radiation exposure; however, debulking is not indicated nor is excision of residual masses at the end of therapy. Regional lymph node assessment is an important component of surgical care, as positive nodal basins require radiation. Depending on the tumor site and biology, sentinel lymph node biopsy vs biopsy of clinically or radiographically concerning nodes is indicated. Therapeutic lymph node dissection is never indicated. Familiarity with site-specific oncologic principles for RMS and participation in a multidisciplinary team including Pediatric Oncology and Radiation Oncology are necessary components of surgical care to ensure optimal outcomes.

Pediatric Rhabdomyosarcomas of the Genitourinary Tract

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in the pediatric and adolescent population, with 350 new cases diagnosed each year. While they can develop anywhere in the body, the genitourinary tract is the second most common primary location for an RMS to develop. Overall survival has improved through the increased use of protocols and multidisciplinary approaches. However, the guidelines for management continue to change as systemic and radiation therapeutics advance. Given the relative rarity of this disease compared to other non-solid childhood malignancies, healthcare providers not directly managing RMS may not be familiar with their presentation and updated management. This review aims to provide foundational knowledge of the management of RMSs with an emphasis on specific management paradigms for those arising from the genitourinary tract. The genitourinary tract is the second most common location for an RMS to develop but varies greatly in symptomology and survival depending on the organ of origin. As the clinical understanding of these tumors advances, treatment paradigms have evolved. Herein, we describe the breadth of presentations for genitourinary RMSs with diagnostic and treatment management considerations, incorporating the most recently available guidelines and societal consensus recommendations.

Imaging in rhabdomyosarcoma: a patient journey

Rhabdomyosarcoma, although rare, is the most frequent soft tissue sarcoma in children and adolescents. It can present as a mass at nearly any site in the body, with most common presentations in the head and neck, genitourinary tract and extremities. The optimal diagnostic approach and management of rhabdomyosarcoma require a multidisciplinary team with multimodal treatment, including chemotherapy and local therapy. Survival has improved over the last decades; however, further improvement in management is essential with current 5-year overall survival ranging from 35% to 100%, depending on disease and patient characteristics. In the full patient journey, from diagnosis, staging, management to follow-up after therapy, the paediatric radiologist and nuclear physician are essential members of the multidisciplinary team. Recently, guidelines of the European paediatric Soft tissue sarcoma Study Group, the Cooperative Weichteilsarkom Studiengruppe and the Oncology Task Force of the European Society of Paediatric Radiology (ESPR), in an ongoing collaboration with the International Soft-Tissue Sarcoma Database Consortium, provided guidance for high-quality imaging. In this educational paper, given as a lecture during the 2022 postgraduate ESPR course, the multi-disciplinary team of our national paediatric oncology centre presents the journey of two patients with rhabdomyosarcoma and discusses the impact on and considerations for the clinical (paediatric) radiologist and nuclear physician. The key learning points of the guidelines and their implementation in clinical practice are highlighted and up-to-date insights provided for all aspects from clinical suspicion of rhabdomyosarcoma and its differential diagnosis, to biopsy, staging, risk stratification, treatment response assessment and follow-up.

Surgical resection of a massive residual retroperitoneal mass after chemotherapy for a paratesticular rhabdomyosarcoma: a case report

INTRODUCTION

Paratesticular rhabdomyosarcoma is a rare and aggressive mesenchymal tumor, accounting for only 7% of all rhabdomyosarcomas. It is mainly encountered in children and adolescents. The standard treatment consists of radical orchidectomy with negative surgical margins. However, chemotherapy is recommended to control retroperitoneal micrometastasis. The place of surgery for progressive retroperitoneal lymph node metastases remains controversial. We present a case of paratesticular rhabdomyosarcoma with progressive retroperitoneal lymph node metastases treated with surgery.

CASE REPORT

We report a case of a 17-year-old North African male with no particular medical history who presented with a left scrotal mass that had been evolving for several months. Beta-human chorionic gonadotropin, alpha-fetoprotein, and lactate dehydrogenase were normal. Scrotal ultrasonography revealed the presence of a 6 cm heterogeneous hypoechogenic tissular mass with cystic areas adherent to the left scrotal wall, which was thickened in some places and vascularized by color Doppler. It exerted a mass effect on the homolateral testicle, which was of average volume. The thoracic-abdominal-pelvic computed tomography scan showed the presence of suspicious paraaortic lymph nodes. The most voluminous one measured 16 × 23 mm². A left orchidectomy was performed. The final pathology report revealed an 8 cm paratesticular rhabdomyosarcoma of the embryonic type that displaced the testicle without invading it. Without going beyond it, it infiltrated the epididymis, the rete testis, and the albuginea. The surgical margin at the level of the spermatic cord was free. The patient had adjuvant chemotherapy (ifosfamide, vincristine, and dactinomycin). The patient had a challenging paraaortic lymph node dissection since the mass enlaced the left ureter and renal vessels. On histological examination, the paraaortic lymph nodes were metastatic.

CONCLUSION

Rhabdomyosarcoma is an aggressive malignancy with high metastatic potential. Therefore, only an accurate diagnosis and early treatment can ensure better survival. Surgery in expert hands seems to be a good option for progressive retroperitoneal nodes. However, further studies are needed to determine the place of surgery in this setting.

Creating a data commons: The INternational Soft Tissue SaRcoma ConsorTium (INSTRuCT)

In this article, we will discuss the genesis, evolution, and progress of the INternational Soft Tissue SaRcoma ConsorTium (INSTRuCT), which aims to foster international research and collaboration focused on pediatric soft tissue sarcoma. We will begin by highlighting the current state of clinical research for pediatric soft tissue sarcomas, including rhabdomyosarcoma and non-rhabdomyosarcoma soft tissue sarcoma. We will then explore challenges and research priorities, describe the development of INSTRuCT, and discuss how the consortium aims to address key research priorities.

Translational Implications for Radiosensitizing Strategies in Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood and adolescence that includes FP-RMS, harboring the fusion oncoprotein PAX3/7-FOXO1 and FN-RMS, often mutant in the RAS pathway. Risk stratifications of RMS patients determine different prognostic groups and related therapeutic treatment. Current multimodal therapeutic strategies involve surgery, chemotherapy (CHT) and radiotherapy (RT), but despite the deeper knowledge of response mechanisms underpinning CHT treatment and the technological improvements that characterize RT, local failures and recurrence frequently occur. This review sums up the RMS classification and the management of RMS patients, with special attention to RT treatment and possible radiosensitizing strategies for RMS tumors. Indeed, RMS radioresistance is a clinical problem and further studies aimed at dissecting radioresistant molecular mechanisms are needed to identify specific targets to hit, thus improving RT-induced cytotoxicity.

Radioresistance in rhabdomyosarcomas: Much more than a question of dose

Management of rhabdomyosarcoma (RMS), the most common soft tissue sarcoma in children, frequently accounting the genitourinary tract is complex and requires a multimodal therapy. In particular, as a consequence of the advancement in dose conformity technology, radiation therapy (RT) has now become the standard therapeutic option for patients with RMS. In the clinical practice, dose and timing of RT are adjusted on the basis of patients' risk stratification to reduce late toxicity and side effects on normal tissues. However, despite the substantial improvement in cure rates, local failure and recurrence frequently occur. In this review, we summarize the general principles of the treatment of RMS, focusing on RT, and the main molecular pathways and specific proteins involved into radioresistance in RMS tumors. Specifically, we focused on DNA damage/repair, reactive oxygen species, cancer stem cells, and epigenetic modifications that have been reported in the context of RMS neoplasia in both in vitro and in vivo studies. The precise elucidation of the radioresistance-related molecular mechanisms is of pivotal importance to set up new more effective and tolerable combined therapeutic approaches that can radiosensitize cancer cells to finally ameliorate the overall survival of patients with RMS, especially for the most aggressive subtypes.

[Clinical features and prognosis in 20 children with rhabdomyosarcoma]

OBJECTIVES

To study the clinical features of children with rhabdomyosarcoma (RMS) and the influencing factors for prognosis.

METHODS

A retrospective analysis was performed on the clinical and follow-up data of 20 children with RMS who were admitted to the Department of Pediatric Hematology, Xiangya Hospital of Central South University, from June 2014 to September 2020.

RESULTS

The most common clinical symptoms of the 20 children with RMS at the first visit were painless mass (13/20, 65%), exophthalmos (4/20, 20%), and abdominal pain (3/20, 15%). According to the staging criteria of Intergroup Rhabdomyosarcoma Study Group (IRSG), there was 1 child (5%) with stage I RMS, 4 (20%) with stage II RMS, 9 (45%) with stage III RMS, and 6 (30%) with stage IV RMS. The median follow-up time was 19 months for the 20 children (range: 3-93 months), with a 2-year overall survival (OS) rate of 79.5% (95%CI: 20.1-24.3) and a 2-year event-free survival (EFS) rate of 72.0% (95%CI: 19.5-23.9). Pleomorphic RMS was associated with the reduced 2-year OS rate (P<0.05), and distant metastasis, IRSG stage IV RMS, and high-risk RMS were associated with the reduced 2-year EFS rate (P<0.05).

CONCLUSIONS

RMS has no specific clinical symptoms at the first visit, with painless mass as the most common symptom. Distant metastasis, IRSG stage, and risk degree may be associated with the prognosis of children with RMS.

Therapy and prognostic significance of regional lymph node involvement in embryonal rhabdomyosarcoma: a report from the European paediatric Soft tissue sarcoma Study Group

PURPOSE

Regional lymph node disease (N1) is a component of the risk-based treatment stratification in rhabdomyosarcoma (RMS). The purpose of this study was to determine the contribution of nodal disease to the prognosis of patients with non-metastatic embryonal RMS (ERMS) and analyse their outcome by treatment received.

PATIENTS AND METHODS

Between 2005 and 2016, 1294 children with ERMS were enrolled in the European paediatric Soft tissue sarcoma Study Group (EpSSG) RMS 2005 protocol, 143 patients with N1. Treatment comprised 9 cycles of ifosfamide, vincristine and dactinomycin. Some patients also received doxorubicin and/or maintenance if enrolled in the randomised studies. Local treatment was planned after 4 cycles of chemotherapy and included surgery to remove macroscopic residual tumour and/or radiotherapy (primary tumour and involved nodes).

RESULTS

N1 patients were older and presented with tumours of unfavourable size, invasiveness, site and resectability. Unlike alveolar RMS, nodal involvement was more frequent in the head and neck area and rare in extremity sites. The 5-year event-free and overall survival were 75.5% and 86.3% for patients with N0, and 65.2% and 70.7% for patients with N1, respectively. The nodal involvement and the result of surgery at diagnosis (Intergroup Rhabdomyosarcoma Study group) were independent prognostic factors on multivariate analysis. Considering only patients with N1 ERMS, we were not able to identify any treatment variables which correlated with the outcome.

CONCLUSION

In the case of nodal involvement, patients with ERMS present different characteristics and a better outcome than alveolar RMS. Regional nodal involvement is an independent prognostic factor in ERMS, therefore it is appropriate to include this population in the high-risk category.

Clinical group and modified TNM stage for rhabdomyosarcoma: A review from the Children's Oncology Group

The Children's Oncology Group (COG) uses Clinical Group (CG) and modified Tumor Node Metastasis (TNM) stage to classify rhabdomyosarcoma (RMS). CG is based on surgicopathologic findings and is determined after the completion of initial surgical procedure(s) but prior to chemotherapy and/or radiation therapy. The modified TNM stage is based on clinical and radiographic findings and is assigned prior to any treatment. These systems have evolved over several decades. We review the history, evolution, and rationale behind the current CG and modified TNM classification systems used by COG for RMS. Data from the seven most recently completed and reported frontline COG trials (D9602, D9802, D9803, ARST0331, ARST0431, ARST0531, ARST08P1) were analyzed, and confirm that CG and modified TNM stage remain relevant and useful for predicting prognosis in RMS. We propose updates based on recent data and discuss factors warranting future study to further optimize these classification systems.

Optimizing Rhabdomyosarcoma Treatment in Adolescents and Young Adults

Rhabdomyosarcoma (RMS) is the most common form of soft tissue sarcoma in children, but can also develop in adolescents and young adults (AYA). The mainstay of treatment is multi-agent chemotherapy, ideally with concomitant local treatment, including surgical resection and/or radiation therapy. Although most treatment decisions for RMS in AYA are based on scientific evidence accumulated through clinical studies of pediatric RMS, treatment outcomes are significantly inferior in AYA patients than in children. Factors responsible for the significantly poor outcomes in AYA are tumor biology, the physiology specific to the age group concerned, refractoriness to multimodal treatments, and various psychosocial and medical care issues. The present review aims to examine the various issues involved in the treatment and care of AYA patients with RMS, discuss possible solutions, and provide an overview of the literature on the topic with several observations from the author's own experience. Clinical trials for RMS in AYA are the best way to develop an optimal treatment. However, a well-designed clinical trial requires a great deal of time and resources, especially when targeting such a rare population. Until clinical trials are designed and implemented, and their findings duly analyzed, we must provide the best possible practice for RMS treatment in AYA patients based on our own expertise in manipulating the dosage schedules of various chemotherapeutic agents and administering local treatments in a manner appropriate for each patient. Precision medicine based on state-of-the-art cancer genomics will also form an integral part of this personalized approach. In the current situation, the only way to realize such a holistic treatment approach is to integrate new developments and findings, such as gene-based diagnostics and treatments, with older, fundamental evidence that can be selectively applied to individual cases.