Incidence and time trends of soft tissue sarcomas in German children 1985–2004 – A report from the population-based German Childhood Cancer Registry

Pediatric Patients with Stage IV Rhabdomyosarcoma Significantly Benefit from Long-Term Maintenance Therapy: Results of the CWS-IV 2002 and the CWS DOK IV 2004-Trials

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma (STS) in childhood. Whereas more than 90% of patients with localized low-risk RMS can be cured, metastatic RMS have a dismal outcome, with survival rates of less than 30%. The HD CWS-96 trial showed an improved outcome for patients receiving maintenance therapy after completing intensive chemotherapy. Consequently, the international clinical trials CWS-IV 2002 and CWS DOK IV 2004 on metastatic disease of STS of the Cooperative Weichteilsarkom Studiengruppe (CWS) were designed in addition to the CWS-2002P trial for localized RMS disease. All patients received a multimodal intensive treatment regimen. To maintain remission, three options were compared: long-term maintenance therapy (LTMT) versus allogeneic hematopoietic stem cell transplantation (alloHSCT) versus high-dose chemotherapy (HDCT). A total of 176 pediatric patients with a histologically confirmed diagnosis of metastatic RMS or RMS-like tumor were included. A total of 89 patients receiving LTML showed a significantly better outcome, with an event-free survival (EFS) of 41% and an overall survival (OS) of 53%, than alloHSCT (n = 21, EFS 19%, p = 0.02, OS 24%, p = 0.002). The outcome of LTML was slightly improved compared to HDCT (n = 13, EFS 35%, OS 34%). In conclusion, our data suggest that in patients suffering from metastatic RMS, long-term maintenance therapy is a superior strategy in terms of EFS and OS compared to alloHSCT. EFS and OS of HDCT are similar in these strategies; however, the therapeutic burden of LTMT is much lower.

Down-Regulated miR-130a/b Attenuates Rhabdomyosarcoma Proliferation via PPARG

Background: Rhabdomyosarcoma (RMS) is one of the most common types of soft-tissue sarcomas in children, and it exhibits a low 5-years survival rate. The survival outcome has shown no significant improvements in the past 30 years miRNA profiling of RMS might therefore provide a novel insight into uncovering new molecular targets for therapy.

Methods: We analyzed miRNA and RNA sequencing data from patients and the TARGET database to reveal the potential miRNA-mRNA axes and validated them in patients’ samples. After the miRNA antagomirs were used to silence the target miRNAs in the cell model, qRT-PCR, western immunoblotting analysis, and proliferation assays were performed to explore the interaction between miR-130a/b and peroxisome proliferator-activated receptor gamma (PPARG) and their effects.

Results: In RMS patients, the expression of miR-130a/b was augmented, and its related PPARG gene was suppressed. Bioinformatics analysis showed that miR-130a/b targeted the PPARG gene and inhibited the proliferation of human RMS cell lines. In addition, rosiglitazone maleate activated the expression of PPARG in human RMS cell lines to suppress proliferation.

Conclusion: miR-130a/b regulates the malignant process in RMS by targeting PPARG. Furthermore, the PPARG agonist rosiglitazone maleate attenuated the proliferation of RD cells and might therefore be of benefit to RMS patients.

Cervical Infantile Fibrosarcoma: a rare cause of paediatric parapharyngeal neck mass

Soft tissue tumors are not uncommon in childhood and comprise entities that range from common to very rare malignancies. Infantile fibrosarcoma (IFS) is a rare pediatric malignancy mainly seen in the first two years of life. The data about the incidence of infantile fibrosarcoma occurring in the neck in the Indian subcontinent is scarce. To the best of our knowledge, only one case of infant cervical IFS has been reported previously in the Indian subcontinent. We present another case of an eight-year-old male patient with a rapidly growing mass on the left side of the neck. He was successfully treated with a combined modality of surgery and chemotherapy with a good outcome. Among the soft tissue tumors of childhood, IFS is a rare entity. It has a good prognosis and lesser chance of distant metastasis as compared to adult fibrosarcoma. Though surgical excision is the mainstay of treatment, chemotherapy also has a significant role in the treatment of primary tumor and metastasis. We discuss the stated case to bring to the notice this uncommon cause, which can be considered as a differential diagnosis of upper cervical swellings. A better understanding of this entity would help in early diagnosis and aggressive treatment, reducing the overall morbidity and mortality.

MicroRNA-410-3p upregulation suppresses proliferation, invasion and migration, and promotes apoptosis in rhabdomyosarcoma cells

Rhabdomyosarcoma (RMS) is one of the most common types of soft tissue sarcoma in children; however, the pathogenesis of RMS is unclear. MicroRNAs (miRs) are involved in the development and progression of RMS. The role of miR-410-3p in RMS cell invasion, migration, proliferation and apoptosis, and its possible mechanism were investigated in the current study. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were performed to detect the expression of miR-410-3p in RMS tissues and cells. In addition, the present study investigated the expression levels of molecules associated with the epithelial-mesenchymal transition (EMT), including E-cadherin, N-cadherin, Slug and Snail, and apoptotic factors, including Bcl-2-associated X protein (bax), cleaved-caspase 3, cleaved poly (ADP-ribose) polymerase (PARP), p53 and Bcl-2. Cell Counting Kit-8, terminal deoxynucleotidyl transferase dUTP nick end labeling and Transwell assays were conducted to determine the functional roles of miR-410-3p. Exogenous expression of miR-410-3p inhibited RMS cell invasion, migration and proliferation, induced apoptosis, suppressed the expression of Snail, Slug, N-cadherin and Bcl-2, and increased the expression of E-cadherin, bax, cleaved-caspase 3, cleaved PARP and p53. In summary, it was proposed that miR-410-3p overexpression suppressed invasion, migration and proliferation, downregulated the expression of EMT-associated molecules, and promoted apoptosis and the expression of apoptotic factors in RMS cells. Therefore, miR-410-3p may serve as a novel tumor suppressor gene in RMS, and could possess diagnostic and therapeutic potentials for the treatment of RMS.

Therapeutic Approaches Targeting PAX3-FOXO1 and Its Regulatory and Transcriptional Pathways in Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a family of soft tissue cancers that are related to the skeletal muscle lineage and predominantly occur in children and young adults. A specific chromosomal translocation t(2;13)(q35;q14) that gives rise to the chimeric oncogenic transcription factor PAX3-FOXO1 has been identified as a hallmark of the aggressive alveolar subtype of RMS. PAX3-FOXO1 cooperates with additional molecular changes to promote oncogenic transformation and tumorigenesis in various human and murine models. Its expression is generally restricted to RMS tumor cells, thus providing a very specific target for therapeutic approaches for these RMS tumors. In this article, we review the recent understanding of PAX3-FOXO1 as a transcription factor in the pathogenesis of this cancer and discuss recent developments to target this oncoprotein for treatment of RMS.

Importance of whole-body imaging with complete coverage of hands and feet in alveolar rhabdomyosarcoma staging

BACKGROUND

Alveolar rhabdomyosarcoma commonly arises in the extremities and is characterized by aggressive biology and high frequency of metastases. Whole-body imaging is increasingly employed in pediatric oncology but not recommended as standard in the staging of soft-tissue sarcomas.

OBJECTIVE

After observing patients with a large symptomatic alveolar rhabdomyosarcoma lesion and a smaller silent lesion in the more distal part of an extremity we sought to estimate the frequency of this constellation.

MATERIALS AND METHODS

We retrospectively evaluated the data of prospectively registered paediatric patients (age <21 years) with alveolar rhabdomyosarcoma in the SoTiSaR (Soft Tissue Sarcoma Registry) of the Cooperative Weichteilsarkom Studiengruppe (CWS) 09/2011-04/2015 with regard to whole-body imaging.

RESULTS

Seventy-five patients were eligible. Images of 57 patients had been submitted for reference consultation, including 80 whole-body examinations in 36 patients. Among them were 5 patients (14%, 95% confidence interval 3-25%) who had been diagnosed because of a symptomatic lesion while an additional silent lesion in the distal part of an extremity had remained unnoticed and had only been detected by later whole-body imaging. It is noteworthy that in 42 (53%) of all 80 whole-body examinations, the hands and feet had been only partially covered or completely excluded.

CONCLUSION

In alveolar rhabdomyosarcoma silent lesions can be overlooked when the distal parts of the limbs are not thoroughly examined and not completely covered by imaging. Missing them influences treatment decisions and prognosis. Our results should be considered when evaluating the potential role of whole-body imaging in rhabdomyosarcoma.

Synovial Sarcoma Recurrence in Children and Young Adults

BACKGROUND

Recurrence of synovial sarcoma (SS) has been associated with poor prognosis. Optimal treatment is unknown due to heterogeneous primary therapies with or without chemotherapy.

METHODS

Data of patients treated in consecutive prospective European Cooperative Weichteilsarkom Studiengruppe trials 1981-2010 with primary localized SS less than 21 years were analyzed. Chemotherapy had been recommended for all SS patients during primary therapy.

RESULTS

Of 220 patients, 52 experienced recurrence a median of 2.5 years (range, 0.3-11.6 years) after their initial diagnosis. Recurrence was local in 22 (42 %), metastatic in 24 (46 %), and combined in 6 (12 %) of the 52 patients. If present, metastases involved the lungs in more than 90 % of the patients. Second remission was achieved by 39 (75 %) of the 52 patients, whereas only 12 (23 %) of the 39 patients maintained it. The median follow-up period for 17 survivors was 6.7 years (range, 3.2-19.6 years). The 5-year post-relapse event-free survival probability was 26 %, and the overall survival probability was 40 %. In the univariable analyses, initial tumor smaller than 3 cm, 2.5 years or longer to recurrence, local relapse only, and R0/R1 resection at relapse correlated with improved survival expectancies. In the multivariable analysis, the only factor retaining significance was R0/R1 resection of the recurrence. No difference between R0 and R1 resections was evident. For the patients with metastatic relapse, maintenance therapy seemed to prolong the time to subsequent recurrences.

CONCLUSION

Although 75 % of the patients with first SS recurrence achieved a second remission, only a minority became long-term, disease-free survivors. They had small tumors at initial diagnosis, local relapse as the only site of involvement, and complete resection of their recurrence. Because the majority of patients relapse subsequently, quality-of-life-based treatment approaches prolonging disease-free intervals are needed.

Primary Metastatic Synovial Sarcoma: Experience of the CWS Study Group

BACKGROUND

Prognostic factors for localized synovial sarcoma are well defined. However, few data exist regarding patients with metastases at diagnosis. Poor outcome is described but the optimal therapeutic regimen remains unclear. Our aim was to assess the outcome, identify prognostic factors, and analyze treatment strategies.

METHODS

Patients <21 years with synovial sarcoma and primary distant metastases treated in the consecutive prospective European Cooperative Weichteilsarkom Studiengruppe trials 1980-2010 were analyzed.

RESULTS

Twenty-nine of 296 patients had primary metastases. Twenty-seven could be included. Median age was 16.7 years. Primaries were mainly located in the limbs (78%) and 74% were ≥10 cm. Metastases involved the lungs in all patients. Two patients presented with synchronous bone metastases. Sixty-three percent of patients achieved a first remission, whereas only 26% maintained it. Relapses were metastatic with pulmonary metastases in nearly all patients. Five-year event-free survival and overall survival (OS) rates were 26% and 30%, respectively. Prognosis was best for patients with oligometastatic lung metastases (5-year OS probability 85%). Prognosis was worse for patients with multiple bilateral lung metastases (5-year OS 13%) and even poorer for those with concurrent bone metastases. Treatment elements associated with superior survival were adequate local therapy of the primary tumor and, if feasible, for metastases, chemotherapy with an ifosfamide/doxorubicin-based regimen. The use of whole lung irradiation was not correlated with better outcomes.

CONCLUSIONS

The overall prognosis of primary metastatic synovial sarcoma is poor. However, individuals with oligometastatic lung metastases had very good chance for long-term survival when treated with adequate multimodal therapy.

Higher rates of metastatic disease may explain the declining trend in Swedish paediatric rhabdomyosarcoma survival rates

AIM

Positive outcomes for paediatric rhabdomyosarcoma (RMS) were high in Sweden during the 1990s, but the last decade has seen decreasing trends in overall survival rates. We investigated the incidence, patient and disease characteristics, treatment and outcome of RMS to see whether any reason could be found for this decline.

METHODS

This study included 210 children under the age of 15 who were diagnosed with RMS and whose details were recorded in the population-based Swedish Childhood Cancer Registry from 1984 to 2010.

RESULTS

The overall annual incidence of RMS was 4.9 per million, and the 5-year overall survival rates were 59 ± 7% in 1984-1989, 78 ± 5% in 1990-1999 and 71 ± 5% in 2000-2010. When patients with localised disease were analysed separately, there was no difference in the 5-year survival rates between 1990 and 1999 (82 ± 5%) and 2000-2010 (81 ± 5%), but the outcome in 1984-1989 (53 ± 8%) was significantly worse. The prevalence of metastatic disease was unexpectedly high during 2000-2010 (28%, p = 0.010), compared to an overall mean of 18% for the whole study period.

CONCLUSION

Our results suggest that a higher rate of metastatic disease may explain the declining trend in overall survival rates in paediatric RMS in Sweden over the last decade.

Tumour volume reduction after neoadjuvant chemotherapy impacts outcome in localised embryonal rhabdomyosarcoma

BACKGROUND

Response (tumour volume reduction) to induction chemotherapy has been used to stratify secondary local and systemic treatment of Intergroup Rhabdomyosarcoma Study Group III (IRSG-III) embryonal rhabdomyosarcoma (RME) in consecutive CWS-trials. To evaluate its actual impact we studied response-related treatment and outcomes.

PROCEDURE

Patients with IRSG-III RME <21 years and non-response (NR, <33% volume reduction) in five consecutive CWS-trials were analysed and compared with partial responders (PAR, ≥ 33% reduction). The NR was reviewed and sub-classified as Objective Response (OR, <0%-33% reduction) or Stable/Progressive Disease (SPD).

RESULTS

Fifty-nine of 529 patients had NR (n = 34 OR, n = 25 SPD). Primary risk-factors including age, tumour size, and TN-classification did not differ between NR and PAR groups but NR had more patients with unfavourable sites comparatively (P = 0.04). There were no differences in primary risk-factors between OR and SPD. Significant factors associated with poor outcome in multivariate analysis were NR, TN-classification, age >10 years, tumour size >5 cm and therapy in older trials. After response assessment n = 24 NR continued to receive induction chemotherapy, n = 32 received other combinations and n = 3 no further chemotherapy. Forty-two non-responders were irradiated, and the tumours were completely resected in n = 20. After a median follow-up of 8 years, 34 NR are alive. Seventeen of 21 failures leading to disease-related deaths were locoregional. The five-year overall survival rate (OS) was 76 ± 4% for PAR, 79 ± 14% for OR, but only 40 ± 19% for SPD (P < 0.001).

CONCLUSION

Response to induction chemotherapy appears to be an important surrogate marker of poor outcome in patients with SPD largely due to ineffective local control.

Challenges in the local treatment of large abdominal embryonal rhabdomyosarcoma

BACKGROUND

Embryonal rhabdomyosarcoma is the most common pediatric soft tissue sarcoma. The best local treatment in large, nonmetastatic primary unresected nongenitourinary embryonal rhabdomyosarcoma of the abdomen (LARME) is however unclear.

METHODS

We analyzed patients with LARME treated in four consecutive CWS trials. All diagnoses were confirmed by reference reviews. Treatment included multiagent chemotherapy and local treatment of the primary tumor with surgery and/or radiotherapy. The impact of primary debulking surgery (PDS) also was studied.

RESULTS

One hundred patients <21 years with a median age of 4 years had LARME. Sixty-one of them had a tumor >10 cm in diameter at diagnosis. PDS was performed in 19 of 100 children. The outcomes of patients with PDS were similar to those of the other patients. In 36 children, the tumor was resected after induction chemotherapy; 60 RME were irradiated. The toxic effects of radiochemotherapy were not significantly increased compared with the nonirradiated patients. With a median follow-up of 10 years, the 5-year EFS and OS were 52 ± 10 and 65 ± 9 %, respectively. Significant risk factors in multivariate analysis were age >10 years; no achievement of complete remission; and inadequate secondary local treatment, defined as incomplete secondary resection or no radiation.

CONCLUSIONS

Children with LARME have a fair prognosis, despite an often huge tumor size and unfavorable primary site, if the tumors can either be resected or irradiated following induction chemotherapy. PDS was only performed in a small subgroup. Radiation performed concomitantly with chemotherapy did not increase the acute toxicity significantly.

Rare malignant pediatric tumors registered in the German Childhood Cancer Registry 2001-2010

BACKGROUND

The German Childhood Cancer Registry (GCCR) annually registers approximately 2,000 children diagnosed with a malignant disease (completeness of registration >95%). While most pediatric cancer patients are diagnosed and treated according to standardized cooperative protocols of the German Society for Pediatric Oncology and Hematology (GPOH), patients with rare tumors are at risk of not being integrated in the network including trials and reference centers.

PROCEDURE

A retrospective analysis of all rare extracranial solid tumors reported to the GCCR 2001-2010 (age <18 years) was undertaken using a combination of the International Classification of Childhood Cancer (ICCC-3) and the International Classification of Diseases-Oncology (ICD-O-3). Tumors accounting for <0.3% of all malignancies were defined as rare (approx. 6 cases/year and registered malignancy).

RESULTS

According to this definition 1,189 rare extracranial solid tumors (18.2% of all malignant extracranial solid tumors) were registered, among these 232 patients (19.5% of rare tumor cases), were not included in preexisting GPOH studies/registries. Within 10 years, the number of registered non-GPOH-trial patients with a rare tumor increased.

CONCLUSIONS

Though most of the GCCR-registered patients with rare malignant tumors are treated within GPOH trials, there is a considerable number of patients that have been diagnosed and treated outside the structures of the GPOH. These patients should be reported to the recently founded German Pediatric Rare Tumor Registry (STEP). Active data accrual and the development of appropriate structures will allow for better registration and improvement of medical care in these patients.

Survival following disease recurrence of primary localized alveolar rhabdomyosarcoma

BACKGROUND

Recurrences in primary localized alveolar rhabdomyosarcoma (RMA) are common. Post-relapse survival is poor. We evaluated prognostic factors including relapse treatment in patients with recurrent RMA.

METHODS

Relapses occurred in 115/235 patients with nonmetastatic RMA treated in four consecutive CWS-trials after achievement of a complete remission. Sufficient information about post-relapse treatment and outcome could be obtained in 99 patients and was retrospectively analyzed.

RESULTS

Nine of 99 patients received no salvage therapy and died after a median of 2 months. The remaining 90 patients received multimodal relapse treatment including mandatory chemotherapy. Recurrences were grossly resected in 39 patients; 57 patients received radiation. At a median follow-up from relapse of 8 years, 20 patients were alive and disease-free (5-year post-relapse survival [PROS] 21.3 ± 8). All surviving patients apart from a single individual had an isolated, circumscribed recurrence. Sixteen of 20 survivors were treated with adequate local relapse therapy (ALRT, i.e., either complete resection or gross resection + radiation). Survival in the subgroup of 27 individuals with circumscribed recurrences and ALRT was significantly better (PROS 53.7 ± 19) compared with disseminated recurrences and/or tumors treated without ALRT. Absence of primary lymph node involvement, circumscribed relapses, ALRT, and achievement of a second CR were identified as independent favorable risk factors.

CONCLUSION

Post-relapse survival for primary localized RMA is generally poor. However, certain patient groups differed significantly in their likelihood of survival and 50% of patients with circumscribed relapses treated with ALRT survived. These findings may form the basis for an evidence-based risk-stratification for recurrent disease including relapse treatment.

Proof-of-concept rare cancers in drug development: the case for rhabdomyosarcoma

Rare diseases typically affect fewer than 200,000 patients annually, yet because thousands of rare diseases exist, the cumulative impact is millions of patients worldwide. Every form of childhood cancer qualifies as a rare disease-including the childhood muscle cancer, rhabdomyosarcoma (RMS). The next few years promise to be an exceptionally good era of opportunity for public-private collaboration for rare and childhood cancers. Not only do certain governmental regulation advantages exist, but these advantages are being made permanent with special incentives for pediatric orphan drug-product development. Coupled with a growing understanding of sarcoma tumor biology, synergy with pharmaceutical muscle disease drug-development programs, and emerging publically available preclinical and clinical tools, the outlook for academic-community-industry partnerships in RMS drug development looks promising.

Identification of the transcription factor HOXB4 as a novel target of miR-23a

The transcription factor HOXB4 not only plays a role during nephrogenesis, but displays also oncogenic characteristics in different malignant neoplasms. An in-silico analysis revealed HOXB4 as a new target of microRNA-23a (miR-23a). Nephroblastomas are malignant embryonal renal neoplasms of childhood resembling developing kidney morphologically and genetically. In our study we verified HOXB4 as a target of miR-23a and furthermore examined the expression of HOXB4 and miR-23a in nephroblastomas. We investigated binding of miR-23a to the 3'UTR of HOXB4 by a luciferase assay. Effects on protein levels of HOXB4 were analysed in Western blot experiments. Expression of HOXB4 in nephroblastomas was assessed by quantitative REALtime PCR (qRT PCR) and immunohistochemistry. The luciferase reporter assay showed a statistically significant downregulation of activity by 72,5% demonstrating direct binding of miR-23a to the 3'UTR of HOXB4. In addition, miR-23a reduced the protein expression of HOXB4 statistically significantly by 65.1%. All 21 nephroblastomas investigated had statistically significantly decreased expression levels of miR-23a. A high level of HOXB4 mRNA was found in five out of 33 nephroblastomas including mixed, blastema-type and stroma-type tumors. Protein expression of HOXB4 was stronger in 15 out of 27 nephroblastomas of all subtypes in a semiquantitative comparison to normal kidney parenchyma. Our study demonstrates for the first time the regulation of HOXB4 by miR-23a. In comparison to mature kidney, nephroblastomas had low levels of miR-23a, and in a majority of them a stronger protein expression in comparison to mature kidney was found.

Rhabdomyosarcoma in adrenal region of a child with hypertension and fever: a case report and literature review

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children but rarely involves the adrenal. We describe a case of alveolar rhabdomyosarcoma (ARMS) of the right adrenal in a 5-year-old boy with a characteristic history of hypertension and recurrent fever. On surveillance imaging, a right adrenal mass was incidentally detected, and a right adrenalectomy was subsequently performed. After the surgery, the fever disappeared simultaneously, and the blood pressure gradually returned to normal level. This is the first reported case in children.

Malignant ectomesenchymoma in children and adolescents: report from the Cooperative Weichteilsarkom Studiengruppe (CWS)

BACKGROUND

Malignant ectomesenchymoma (MEM) is a soft tissue tumor with heterologous rhabdomyoblastic components believed to arise from pluripotent migratory neural crest cells. To date merely 50 cases have been published and the knowledge about the course of disease and optimal treatment is limited.

METHODS

Six patients with MEM were registered 1996-2009. The diagnosis was confirmed according to current criteria. Their treatment and outcome was analyzed.

RESULTS

The median age of the three females and three males was 0.6 years (range, 0.2-13.5). The mesenchymal component in all tumors was rhabdomyosarcoma (RMS), the neural component ganglioneuroblastoma/neuroblastoma (n = 5) and peripheral primitive neuroectodermal tumor in one case. Five patients presented with localized, one with metastatic disease. All but one patient received multiagent chemotherapy during their initial treatment. The tumors of 4/5 patients with localized MEM were at least grossly resected at best surgery; the patient without gross resection was additionally irradiated. Three of four evaluable tumors responded well to induction chemotherapy. All patients achieved a first complete remission (CR), but three recurrences (two local, one systemic) occurred. The individual with metastatic MEM did not survive, but all five patients with localized MEM are currently alive in CR with a median follow-up of 5 years (range: 2.1-13.7).

CONCLUSIONS

Risk-factors and outcome of MEM appear to be comparable with other highly malignant pediatric soft tissue sarcoma when a multimodal treatment strategy including chemotherapy and adequate local treatment is pursued. We propose that treatment of patients with MEM be done according to pediatric protocols similar to other rhabdomyosarcoma-like soft tissue sarcoma.

Vascular and perivascular lesions of skin and soft tissues in children and adolescents

Vascular anomalies in children and adolescents are the most common soft tissue lesions and include reactive, malformative, and neoplastic tumefactions, with a full spectrum of benign, intermediate, and malignant neoplasms. These lesions are diagnostically challenging because of morphologic complexity and recent changes in classification systems, some of which are based on clinical features and others on pathologic findings. In recent decades, there have been significant advances in clinical diagnosis, development of new therapies, and a better understanding of the genetic aspects of vascular biology and syndromes that include unusual vascular proliferations. Most vascular lesions in children and adolescents are benign, although the intermediate locally aggressive and intermediate rarely metastasizing neoplasms are important to distinguish from benign and malignant mimics. Morphologic recognition of a vasoproliferative lesion is straightforward in most instances, and conventional morphology remains the cornerstone for a specific diagnosis. However, pathologic examination is enhanced by adjunctive techniques, especially immunohistochemistry to characterize the type of vessels involved. Multifocality may cause some uncertainty regarding the assignment of "benign" or "malignant." However, increased interest in vascular anomalies, clinical expertise, and imaging technology have contributed greatly to our understanding of these disorders to the extent that in most vascular malformations and in many tumors, a diagnosis is made clinically and biopsy is not required for diagnosis. The importance of close collaboration between the clinical team and the pathologist cannot be overemphasized. For some lesions, a diagnosis is not possible from evaluation of histopathology alone, and in a subset of these, a specific diagnosis may not be possible even after all assembled data have been reviewed. In such instances, a consensus diagnosis in conjunction with clinical colleagues guides therapy. The purpose of this review is to delineate the clinicopathologic features of vascular lesions in children and adolescents with an emphasis on their unique aspects, use of diagnostic adjuncts, and differential diagnosis.

Some general considerations about the clinicopathologic aspects of soft tissue tumors in children and adolescents

Soft tissue tumors in children and adolescents are an important group of neoplasms, pseudoneoplasms, and tumefactive malformations with some distinctive clinicopathologic, genetic, syndromic, and therapeutic implications. In addition to the basic pathologic examination, there is the availability of diagnostic adjuncts in various settings based upon the histopathologic features that facilitate and/or corroborate a diagnosis. Immunohistochemistry, cytogenetics, molecular genetics, and an ever-increasing array of new technologies are available to address specific diagnostic questions and even potential therapeutic strategies. This review focuses upon some of the unique aspects of soft tissue tumors in children, including the classification, approach to the diagnosis, grading, clinical and pathologic staging, therapy-related changes, pathogenesis, and risk factors.

[Fibrosarcoma in children and adolescents: different entities for the same name]

Fibrosarcomas (FS) are rare malignant tumors in pediatrics, classified in the heterogeneous non-rhabdomyosarcomas group of malignant mesenchymal tumors. Infantile FS are found typically in children less than 2 years of age, and include congenital FS usually occurring in infants in the first 3 months of life. Histological diagnosis can be difficult; and confirmed with detection by molecular biology of the ETV6-NTRK3 fusion protein. FS is most often a localized disease at diagnosis, with involvement of an extremity. The management of these patients must be multidisciplinary, to define the different phases of treatment and avoid mutilating surgery. Cellular or atypical mesoblastic nephroma (MN) is a subtype of malignant pediatric renal tumors, most often present in children of less than 3 months. Histopathological characteristics of the cellular MN are very close to the congenital FS due to a fusion transcript common to both diseases. Treatment schedule is defined by initial local stage of the disease. FS called "adult-type" found exceptionally in childhood occur most often after 10 years old. Adult FS differ from infantile FS in their clinical presentation because of a strong local aggressiveness and problematic appearance of metastasis in 50% of cases, sometimes late. These three diseases present therefore histological similarities. Both have a common name but different clinical presentation and outcome: infantile FS and adult FS. Two have different names and initial location but similar histology, chromosomal rearrangement, sensitivity to chemotherapy and outcome: the congenital FS and cellular mesoblatic nephroma. Authors present a review of the literature of these entities.

Incidence and survival of pediatric soft tissue sarcomas in moscow region, Russian Federation, 2000-2009

The aim of the study was to assess the incidence and survival rates of soft tissue sarcomas (STSs) in children 0-14 years of age in Moscow Region, Russian Federation. The database of childhood population-based cancer registry of Moscow Region was used as a data source. Tumors were stratified according to International Classification of Childhood Cancer, 3d ed. Sixty-eight cases of STS were registered from 2000 to 2009. Crude incidence rate was 0,78, and age-standardized incidence rate using World Standard Population was 0,81 per 100.000 children/year. The highest age-specific incidence was observed in infants: 1,76 per 100.000 children/year. Rhabdomyosarcoma (RMS) was the most common histological type comprising 54,4% of all STS. 5-year observed survival (OS) of all patients with STS was 64,1 (95% CI 55,0-73,2). There was no statistically significant difference in OS between RMS-59,2 (95% CI 47,0-71,4) and nonrhabdomyosarcoma STS-69,3 (95% CI 55,8-82,8) (P = 0.63). Incidence and survival rates of STS observed in the study were comparable to the other Eastern European countries.

Surgical treatment of lung metastases in patients with embryonal pediatric solid tumors: an update

Distant metastases regularly occur in children with solid tumors. The most affected organ is the lung. Nearly in all extracranial pediatric solid tumors, the presence of lung metastases is associated with an adverse prognosis for the children. Therefore, the correct treatment of lung metastases is essential and influences the outcome. Despite different national and international trials for pediatric tumor entities, specific surgical aspects or guidelines for lung metastases are usually not addressed thoroughly in these protocols. The aim of this article is to present the diagnostic challenges and principles of surgical treatment by focusing on the influence of surgery on the outcome of children. Special points of interest are discussed that emphasize sarcomas, nephroblastomas, hepatoblastomas, and other tumors. Surgery of lung metastases is safe, has a positive impact on the patients' prognosis, and should be aggressive depending on the tumor entity. An interdisciplinary approach, including pediatric oncology and radiology, is mandatory in any case.

Thoracic neoplasms at the Jena reference center for soft tissue tumors

INTRODUCTION

The Jena Soft Tissue Tumor Reference Center is the major German pathology institute for consultation of malignant mesenchymal tumors. Here, we present the clinicopathological data on thoracic soft tissue tumors of a two-year period.

METHODS

The tumors were analyzed according to their localization, type (soft tissue tumor, other tumor type, non-neoplastic lesion) and biological behavior. The frequency of the defined soft tissue tumor entities were considered after categorizing the cases according to the WHO Classification of Tumors. Gender and age were also assessed.

RESULTS

In total, 1,071 cases of thoracic tumors were recorded within the 2 years. The majority were non-epithelial lesions (75.3%, n = 806/1,071), of which 68.1% (n = 549/806) were malignant or intermediate malignant. 107 non-epithelial lesions involved the lung and 37 the pleura. By far the most common lung and pleural tumors were undifferentiated sarcomas. In the lung, other frequent entities were solitary fibrous tumors, synovial sarcomas and leiomyosarcomas. We also recorded 13 non-epithelial tumors of the heart and 66 tumors of the breast with angiosarcomas being the most frequent subtype. There was a female predominance for vascular neoplasms, while men prevailed for adipocytic tumors.

CONCLUSIONS

Our study provides information about the frequency, distribution, age and gender of patients with thoracic soft tissue tumors including several rare entities. Thus, it may help in the differential diagnosis of these neoplasms. In addition, we present a model highlighting the potential progression of lung carcinoma to undifferentiated sarcoma via the process of epithelial-mesenchymal transition.

Prognostic value of PAX-FKHR fusion status in alveolar rhabdomyosarcoma: a report from the cooperative soft tissue sarcoma study group (CWS)

BACKGROUND

Alveolar Rhabdomyosarcomas (RMA) are characterized by chromosomal translocations, fusing the PAX3 or PAX7 gene with FKHR in about 85%. Previous studies have suggested that the fusion type is associated with prognosis. In order to investigate the predictive value of the PAX-FKHR fusion status on disease outcome of patients with RMA treated in the CWS trials we performed a retrospective analysis.

PROCEDURE

Between 1986 and 2004, out of 446 patients with RMA treated in four consecutive CWS trials, tumor samples from 126 patients were available for RT-PCR analysis. Survival depending on fusion status in context with known clinical risk-factors was analyzed.

RESULTS

Out of 126 samples, 121 had adequate quality for PAX-FKHR fusion status analysis. PAX-FKHR fusions were detected in 101 samples: 60% PAX3-FKHR and 24% PAX7-FKHR fusions, 17% were fusion-negative. There was no significant difference in survival between patients with PAX3-FKHR versus PAX7-FKHR positive tumors. The fusion transcript negative cohort showed a more favorable outcome than the fusion transcript positive cohort among patients with metastatic disease. From the established clinical risk-factors none was associated with a significantly higher risk of failure or death in a multivariate analysis.

CONCLUSIONS

PAX-FKHR fusion type was not a significant predictor for survival in our analysis. More extensive molecular analyses are needed to identify features with prognostic relevance and useful therapeutic impact.

Embryonal rhabdomyosarcoma with metastases confined to the lungs: report from the CWS Study Group

BACKGROUND

Embryonal rhabdomyosarcoma [RME] is the most common pediatric soft tissue sarcoma. Whereas the prognosis of localized rhabdomyosarcoma has improved, it remains poor for metastatic disease.

METHODS

We analyzed RME-patients with isolated pulmonary metastases [PRME] treated in four consecutive CWS-trials. Treatment included multiagent chemotherapy and local treatment of the primary tumor. Therapy of lung metastases after induction chemotherapy depended on response and individual decisions.

RESULTS

Twenty-nine patients <21 years had PRME. Their median age was six years, the median follow-up nine years. Twenty-eight children had their primary tumor located in an unfavorable site and 22 of the primaries were >5 cm. In addition to conventional chemotherapy, seven patients received high-dose treatment and eight patients oral metronomic chemotherapy. The lung metastases were in remission after induction chemotherapy in 22 individuals. 19 patients received no local treatment of metastases; 3 patients had pulmonary metastasectomy and lung radiation was administered to 9 individuals. In total, 24/29 patients achieved a complete remission [CR]. Actuarial 5-year event-free and overall survival for all patients was 37.9 ± 18% and 48.7 ± 18%, respectively; it was 45.8 ± 20% and 58.3 ± 20% for the 24 patients who achieved a CR. Local treatment of metastases had no impact on the failure pattern. Younger age, good response, achievement of CR and maintenance-treatment were favorable prognostic factors in univariate analysis.

CONCLUSIONS

Children with PRME have a fair prognosis. Local treatment of metastases did not improve outcome in our sample. Metronomic treatment may be an attractive option for PREM-patients.

Rhabdomyosarcoma in children: a SEER population based study

OBJECTIVE

To examine incidence and outcomes for pediatric rhabdomyosarcoma (RMS).

METHODS

The SEER registry was examined for patients with RMS < 20 y old.

RESULTS

Overall, 1544 patients were identified for an incidence of 0.4414/100,000 per year. Males outnumbered females 3:2. Tumors were classified as embryonal (67%), alveolar (32%), and pleomorphic (1%). Alveolar and pleomorphic RMS were more common in adolescents, whereas embryonal type was more common in younger children (P = 0.0001). Pleomorphic (47%) and alveolar (39%) RMS commonly presented with distant disease, in contrast to embryonal (25%). Most patients had surgical resection (81%) and radiotherapy (63%). Overall, 5- and 10-y survival was 60% and 57%, respectively. Univariate analysis identified higher survival for age < 10 y, local stage, favorable site, embryonal type, <5 cm tumor size, and surgical resection. Multivariate analysis identified non-embryonal type (HR 1.451), non-favorable site (HR 1.570), no surgery (HR 1.726), age ≥ 10 y (HR 1.734), 1973-1978 diagnosis year (HR 1.730), and distant disease (HR 3.456) as independent predictors of mortality.

CONCLUSIONS

Embryonal histology, the most common type of pediatric RMS, presents in young children and has better prognosis than alveolar or pleomorphic types. Patients with embryonal tumors, favorable tumor location, age < 10 y, localized disease, and surgical resection have improved survival.

Pediatric urologic rhabdomyosarcoma

PURPOSE OF REVIEW

To review on the most significant and recent developments in basic research, diagnostic, and therapeutic aspects of genitourinary rhabdomyosarcomas (RMS) in children.

RECENT FINDINGS

Collaborative studies have dramatically improved therapy of genitourinary RMS with a remarkable improvement of survival. However, refractory or relapsed disease is still the most demanding challenge. Advances in our understanding of RMS molecular biology evolve new risk stratification and new therapeutic targets such as growth factors and their receptors. High-quality imaging is crucial and integrated fluorodeoxyglucose positron emission tomography/computed tomography significantly increased sensitivity. Alternative chemotherapeutical strategies were proven. Mutilating primary surgery should be avoided. Modern irradiation modalities with decrease of local radiation dose and, therefore, less long-term effects are new tools in the therapeutic arsenal of therapists.

SUMMARY

Therapy-associated morbidity after current RMS treatment can be significantly decreased by including modern strategies, especially in the field of irradiation. However, the follow-up is too short so far to make a distinct decision. The advances in understanding tumor biology may give rise to clinically relevant new therapeutic targets in the near future.

Cooperative trial CWS-91 for localized soft tissue sarcoma in children, adolescents, and young adults

PURPOSE

To improve risk-adapted therapy for localized childhood soft tissue sarcoma within an international multicenter setting.

PATIENTS AND METHODS

Four hundred forty-one patients younger than 21 years with localized rhabdomyosarcoma and rhabdomyosarcoma-like tumors (ie, extraosseous tumors of the Ewing family, synovial sarcoma, and undifferentiated sarcoma) were eligible. Therapy was stratified according to postsurgical stage, histology, and tumor site. In unresectable tumors, treatment was further adapted depending on response to induction chemotherapy, TN classification, tumor size and second-look surgery. A novel five-drug combination of etoposide, vincristine, dactinomycin, ifosfamide, and doxorubicin (EVAIA) was evaluated for high-risk patients, but cumulative chemotherapy dosage and treatment duration were reduced for the remaining individuals as compared with that of the previous trial CWS-86. Hyperfractionated accelerated radiotherapy (HART) was recommended at doses of either 32 or 48 Gy.

RESULTS

At a median follow-up of 8 years, 5-year event-free survival (EFS) and overall (OS) survival for the entire cohort was 63% +/- 4% and 73% +/- 4%, respectively (all survival rates in this abstract are calculated and displayed with +/-95% CI). EFS/OS rates by histology were 60% +/- 5%/72% +/- 5% in rhabdomyosarcoma, 62% +/- 10%/69% +/- 10% for Ewing tumors of soft tissues, 84% +/- 12%/90% +/- 10% for synovial sarcoma, and 67% +/- 38%/83% +/- 30% for undifferentiated sarcoma, respectively. Response to one cycle of the five-drug combination EVAIA was similar to that of the four-drug combination VAIA used in CWS-86. Two hundred twelve patients with rhabdomyosarcoma underwent radiation (EFS, 66% +/- 6%); 53 of those patients had a favorable risk profile and received 32 Gy of HART (EFS, 73% +/- 12%). TN classification, tumor site, tumor size, histology, and age were prognostic in univariate analysis.

CONCLUSION

Improved risk stratification enabled decreased therapy intensity for selected patients without compromising survival. Intensified chemotherapy with EVAIA did not improve outcome of localized high-risk rhabdomyosarcoma.