Clinical and Cytogenetic Profiles of Rhabdomyosarcoma with Bone Marrow Involvement in Korean Children: A 15-Year Single-Institution Experience

Children and young adults with newly diagnosed rhabdomyosarcoma metastatic to bone treated on Children's Oncology Group studies

BACKGROUND

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Despite bone metastases being present in 5% of patients at diagnosis, there are limited studies examining these outcomes. We sought to define the prognostic factors, clinical courses, and outcomes of children treated on Children's Oncology Group (COG) clinical trials with RMS metastatic to bone at diagnosis.

METHODS

We performed a retrospective analysis of patients diagnosed with bone metastatic RMS enrolled on COG RMS clinical trials (D9802, D9803, ARST0431, or ARST08P1) between 1997 and 2013.

RESULTS

RMS metastatic to bone was identified in 154 patients at a median age of 14.9 years at diagnosis. Fifty-eight percent of patients were male, 90% had metastases at additional sites, 74% had alveolar histology, and extremity was the most common primary site (31%). Eighty-six percent of patients (n = 133) received radiation therapy. The 3- and 5-year event-free survival (EFS) was 15.4% and 14.5%, respectively. The 3- and 5-year overall survival (OS) was 30.4% and 18.0%, respectively. We identified alveolar histology, FOXO1 fusion presence, unfavorable primary location, higher Oberlin score, and lack of radiation as poor prognostic characteristics for both EFS and OS in univariate analysis. Lack of radiation was not significant when excluding patients with events prior to 20 weeks.

CONCLUSIONS

This study is the largest analysis of patients with bone metastatic RMS, and defines the poor overall outcomes and negative prognostic factors for these patients. They may be eligible for therapy deintensification for improved quality of life or pursuit of novel treatments/approaches, which are desperately needed.

Arsenic sulfide enhances radiosensitivity in rhabdomyosarcoma via activating NFATc3-RAG1 mediated DNA double strand break (DSB)

Rhabdomyosarcoma (RMS) represents one of the most lethal soft-tissue sarcomas in children. The toxic trace element arsenic has been reported to function as a radiosensitizer in sarcomas. To investigate the role of arsenic sulfide (As4S4) in enhancing radiation sensitization in RMS, this study was conducted to elucidate its underlying mechanism in radiotherapy. The combination of As4S4 and radiotherapy showed significant inhibition in RMS cells, as demonstrated by the cell counting kit-8 (CCK-8) assay and flow cytometry. Subsequently, we demonstrated for the first time that As4S4, as well as the knockdown of NFATc3 led to double-strand break (DSB) through increased expression of RAG1. In vivo experiment confirmed that co-treatment efficiently inhibited RMS growth. Furthermore, survival analysis of a clinical cohort consisting of 59 patients revealed a correlation between NFATc3 and RAG1 expression and overall survival (OS). Cox regression analysis also confirmed the independent prognostic significance of NFATc3 and RAG1.Taken together, As4S4 enhances radiosensitivity in RMS via activating NFATc3-RAG1 mediated DSB. NFATc3 and RAG1 are potential therapeutic targets. As4S4 will hopefully serve as a prospective radio-sensitizing agent for RMS.

Mechanism and clinical progression of solid tumors bone marrow metastasis

The rich blood supply of the bone marrow provides favorable conditions for tumor cell proliferation and growth. In the disease's early stages, circulating tumor cells can escape to the bone marrow and form imperceptible micro metastases. These tumor cells may be reactivated to regain the ability to grow aggressively and eventually develop into visible metastases. Symptomatic bone marrow metastases with abnormal hematopoiesis solid tumor metastases are rare and have poor prognoses. Treatment options are carefully chosen because of the suppression of bone marrow function. In this review, we summarized the mechanisms involved in developing bone marrow metastases from tumor cells and the clinical features, treatment options, and prognosis of patients with symptomatic bone marrow metastases from different solid tumors reported in the literature.

Prognosis of children and young adults with newly diagnosed rhabdomyosarcoma metastatic to bone marrow treated on Children's Oncology Group studies

BACKGROUND

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Metastatic disease occurs in 16% of all RMS cases and has a poor prognosis. There are limited studies examining the outcomes specific to patients with RMS metastatic to bone marrow despite an incidence of 6% at diagnosis. Our study aims to document the outcomes, prognostic factors, and clinical courses of children presenting with RMS metastatic to bone marrow treated on Children's Oncology Group (COG) cooperative trials.

METHODS

We performed a retrospective analysis of the patients diagnosed with RMS metastatic to bone marrow between 1997 and 2013 enrolled on one of four COG RMS clinical trials of D9802, D9803, ARST0431, and ARST08P1.

RESULTS

We identified 179 cases with RMS metastatic to bone marrow. Patients had a median age of 14.8 years, 58% were male, predominantly alveolar histology (76%), extremity was the most common primary site (32%), and 87% had metastatic disease to additional sites; 83% (n = 149) received radiation as a treatment modality. The 3- and 5-year event-free survival was 9.4% and 8.2%, respectively. The 3- and 5-year overall survival was 26.1% and 12.6%, respectively. Age ≥10 years, alveolar histology, FOXO1 fusion presence, unfavorable primary location, higher Oberlin score, and lack of radiation were identified as poor prognostic/predictive characteristics.

CONCLUSIONS

This study represents the largest analysis of RMS metastatic to bone marrow, defining the poor prognostic outcome for these patients. These patients may be eligible for therapy deintensification or early pursuit of novel treatments/approaches that are desperately needed.

No Improvement of Survival for Alveolar Rhabdomyosarcoma Patients After HLA-Matched Versus -Mismatched Allogeneic Hematopoietic Stem Cell Transplantation Compared to Standard-of-Care Therapy

Background

Patients with stage IV alveolar rhabdomyosarcoma (RMA) have a 5-year-survival rate not exceeding 30%. Here, we assess the role of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for these patients in comparison to standard-of-care regimens. We also compare the use of HLA-mismatched vs. HLA-matched grafts after reduced vs. myeloablative conditioning regimens, respectively.

Patients and Methods

In this retrospective analysis, we compare event-free survival (EFS), overall survival (OS), and toxicity of HLA-mismatched vs. -matched transplanted patients in uni- and multivariate analyses (total: n = 50, HLA-matched: n = 15, HLA-mismatched: n = 35). Here, the factors age at diagnosis, age at allo-HSCT, sex, Oberlin score, disease status at allo-HSCT, and HLA graft type are assessed. For 29 primarily transplanted patients, three matched non-transplanted patients per one transplanted patient were identified from the CWS registry. Outcomes were respectively compared for OS and EFS. Matching criteria included sex, age at diagnosis, favorable/unfavorable primary tumor site, and metastatic sites.

Results

Median EFS and OS did not differ significantly between HLA-mismatched and -matched patients. In the mismatched group, incidence of acute GvHD was 0.87 (grade III-IV: 0.14) vs. 0.80 in HLA-matched patients (grade III-IV: 0.20). Transplant-related mortality (TRM) of all patients was 0.20 and did not differ significantly between HLA-mismatched and -matched groups. A proportion of 0.58 relapsed or progressed and died of disease (HLA-mismatched: 0.66, HLA-matched: 0.53) whereas 0.18 were alive in complete remission (CR) at data collection. Multivariate and competing risk analyses confirmed CR and very good partial response (VGPR) status prior to allo-HSCT as the only decisive predictor for OS (p < 0.001). Matched-pair survival analyses of primarily transplanted patients vs. matched non-transplanted patients also identified disease status prior to allo-HSCT (CR, VGPR) as the only significant predictor for EFS. Here, OS was not affected, however.

Conclusion

In this retrospective analysis, only a subgroup of patients with good response at allo-HSCT survived. There was no survival benefit of allo-transplanted patients compared to matched controls, suggesting the absence of a clinically relevant graft-versus-RMA effect in the current setting. The results of this analysis do not support further implementation of allo-HSCT in RMA stage IV patients.

Rhabdomyosarcoma With Diffuse Bone Marrow Metastases

Rhabdomyosarcoma is a highly aggressive cancer that is generally considered a disease of childhood. A vast majority of cases occur in those below the age of 20. Rhabdomyosarcoma can occur in any soft tissue in the body but is primarily found in the head, neck, orbit, genitourinary tract, genitals, and extremities. Prognosis is closely tied to the location of the primary tumor and the extent of metastatic spread. As with most sarcomas, rhabdomyosarcoma has a pattern of hematogenous spread which favors metastasis to the lungs. Other common areas include bone marrows, liver, breasts, and brain. One unusual pattern is the presence of diffuse bone marrow metastases in absence of significant soft tissue disease other than primary (no distant nodal disease, absence of visceral disease in chest and abdomen). Frequently in such cases, patients may have initial presentation similar to hematologic malignancy especially when the primary tumor is not evident. This pattern has been rarely described in the radiology literature. This pattern appears to be well documented in pathology literature. Even more rarely, in some cases, the primary tumor site may not be found after imaging and may remain undetermined even postmortem - only diagnosed by bone marrow aspiration. Awareness of this unique pattern is clearly important for radiologists, especially pediatric radiologists, as misdiagnosis can lead to delay in appropriate treatment that ultimately results in increased mortality. We present a case of rhabdomyosarcoma with this unique pattern of bone marrow metastases in which initial differential diagnosis favored a leukemic picture. This paper will go over the diagnostic techniques utilized throughout our patient’s disease course as well as treatment.

Mechanisms, Diagnosis and Treatment of Bone Metastases

Bone and bone marrow are among the most frequent metastatic sites of cancer. The occurrence of bone metastasis is frequently associated with a dismal disease outcome. The prevention and therapy of bone metastases is a priority in the treatment of cancer patients. However, current therapeutic options for patients with bone metastatic disease are limited in efficacy and associated with increased morbidity. Therefore, most current therapies are mainly palliative in nature. A better understanding of the underlying molecular pathways of the bone metastatic process is warranted to develop novel, well-tolerated and more successful treatments for a significant improvement of patients' quality of life and disease outcome. In this review, we provide comparative mechanistic insights into the bone metastatic process of various solid tumors, including pediatric cancers. We also highlight current and innovative approaches to biologically targeted therapy and immunotherapy. In particular, we discuss the role of the bone marrow microenvironment in the attraction, homing, dormancy and outgrowth of metastatic tumor cells and the ensuing therapeutic implications. Multiple signaling pathways have been described to contribute to metastatic spread to the bone of specific cancer entities, with most knowledge derived from the study of breast and prostate cancer. However, it is likely that similar mechanisms are involved in different types of cancer, including multiple myeloma, primary bone sarcomas and neuroblastoma. The metastatic rate-limiting interaction of tumor cells with the various cellular and noncellular components of the bone-marrow niche provides attractive therapeutic targets, which are already partially exploited by novel promising immunotherapies.

Pediatric rhabdomyosarcoma with bone marrow metastasis

BACKGROUND

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of adolescence and childhood. Although most patients with localized RMS are cured, outcome of those with metastatic disease remains unsatisfactory. RMS with bone marrow (BM) metastasis accounts for approximately 6% of all cases with RMS and has a 3-year event-free survival of 14%. Our study aims to describe our institution's experience of patients with metastatic RMS with BM involvement.

METHODS

This was a single-institution retrospective study from Memorial Sloan Kettering Kids, a tertiary pediatric oncology center. Patients with RMS who were diagnosed with BM metastasis between 1998 and 2018 were identified from pathology reports.

RESULTS

For patients with RMS and BM positivity at diagnosis (N = 27), the median survival was 1.5 years. The 1-, 2-, and 3-year overall survival (OS) were 81%, 32%, and 20%, respectively. There is one long-term (defined as >4 year) survivor who is still alive 14.9 years after diagnosis despite two metastatic recurrences. An Oberlin status of 4 that included BM metastasis portended a 3-year OS of 0%.

CONCLUSIONS

Although most patients will respond to initial therapy, BM metastasis at the time of diagnosis lends a near-fatal diagnosis in pediatric patients with RMS. Novel therapies are desperately needed to consolidate their initial remission.

Alveolar rhabdomyosarcoma with unusual cytogenetic findings: one more case and review of the literature

Alveolar rhabdomyosarcoma (ARMS), a histological subtype of rhabdomyosarcoma (RMS), is characterized by an unfavorable clinical outcome. In most ARMS cases, an indicative chromosomal alteration is identified. The recurrent translocation of FKHR with either PAX3 or PAX7 genes results in the encoding of chimeric transcription factors that boost tumorigenesis. Besides structural mutations, the copy number of these genes also contributes to the oncogenic activity. In our case, a 12-year-old female patient was diagnosed with a 4 cm pelvic mass. Histopathological examination indicated an alveolar type of RMS. Subsequent FISH analysis with a dual color break-apart probe identified positive signals of FKHR3 gene break, as well as the rare event of a synchronous aneuploidy and gene deletion of FKHR. Our findings lead to the conclusion that a systematic break-apart probe FKHR FISH analysis in ARMS, confirms the diagnosis and elucidates the full spectrum of genomic alterations of this malignancy.

Emerging Pathogenic and Prognostic Significance of Paired Box 3 (PAX3) Protein in Adult Gliomas

Gliomas present the most common type of brain tumors in adults, characterized by high morbidity and mortality. In search of potential molecular targets, members of paired box (PAX) family have been found expressed in neural crest cells, regulating their proliferation, apoptosis, migration and differentiation. Recently, PAX3 overexpression has been implicated in glioma tumorigenesis by enhancing proliferation, increasing invasiveness and inducing resistance to apoptosis of glioma cells, while maintaining brain glioma stem cells (BGSCs) stemness. Although the oncogenic potential of PAX3 in gliomas is still under investigation, experimental evidence suggests that PAX3 function is mainly mediated through the canonical and non-canonical Wnt signaling pathway as well as through its interaction with GFAP and p53 proteins. In addition, PAX3 may contribute to the chemoresistance of glioma cells and modulates the effectiveness of novel experimental therapies. Further evidence indicates that PAX3 may represent a novel diagnostic and prognostic biomarker for gliomas, facilitating personalized treatment. This review addresses the emerging role of PAX3 in glioma diagnosis, prognosis and treatment, aiming to shed more light on the underlying molecular mechanisms that could lead to more effective treatment approaches.