Receptor tyrosine kinase inhibitors for the treatment of osteosarcoma and Ewing sarcoma.

Adjuvant chemotherapy for osteosarcoma and Ewing sarcoma consists of conventional cytotoxic regimens that have changed little over the past decades. There is an urgent need for agents that are more effective and have less long-term toxicity. Receptor tyrosine kinases regulate cell growth and proliferation of these tumors, and small-molecule inhibitors for many of these kinases are now available. In this article, we review published phase II trials for patients with recurrent disease and highlight the pathways targeted by available agents, as well as the toxicity and efficacy results seen to date. We also discuss the difficulties in identifying biomarkers to facilitate rational patient selection, as well as published and proposed strategies for how these inhibitors can be combined with conventional chemotherapy or other targeted agents. It is hoped future trials can capitalize on this growing experience to optimize the use of this exciting class of agents.

Phase II trial of gemcitabine and nab-paclitaxel in patients with recurrent Ewing sarcoma: A report from the National Pediatric Cancer Foundation.

BACKGROUND: The combination of gemcitabine and docetaxel is often used to treat patients with recurrent sarcoma. Nab-paclitaxel is a taxane modified to improve drug exposure and increase intratumoral accumulation and, in combination with gemcitabine, is standard therapy for pancreatic cancer. Applying the dosages and schedule used for pancreatic cancer, we performed a phase II trial to assess the response rate of gemcitabine and nab-paclitaxel in patients with relapsed Ewing sarcoma. PROCEDURE: Using a Simon's two-stage design to identify a response rate of ≥ 35%, patients received nab-paclitaxel 125 mg/m2 followed by gemcitabine 1000 mg/m2 i.v. on days 1, 8, and 15 of four-week cycles. Immunohistochemical analysis of archival tissue was performed to identify possible biomarkers of response. RESULTS: Eleven patients from four institutions enrolled, with a median age of 22 years (range, 14-27). Patients were heavily pretreated (median 3 prior regimens, range, 1-7). Thirty-five cycles were administered (median 2, range, 1-8). Accrual was stopped after 11 patients, due to only one confirmed partial response. Two other patients had partial responses after two cycles, but withdrew because of adverse effects or progression before confirmation of continued response. The predominant toxicity was myelosuppression, and four (36%) patients were removed due to hematologic toxicity despite pegfilgrastim and dose reductions. Expression of secreted protein, acidic and rich in cysteine (SPARC) and CAV-1 in archival tumors was not predictive of clinical benefit in this small cohort of patients. CONCLUSIONS: In patients with heavily pretreated Ewing sarcoma, the confirmed response rate of 9% was similar to multi-institutional studies of gemcitabine and docetaxel.

Immunotherapy for osteosarcoma: Where do we go from here?

Osteosarcoma is the most common bone tumor in children and young adults, with few advances in survival and treatment, especially for metastatic disease, in the last 30 years. Recently, immunotherapy has begun to show promise in various adult cancers, but the utility of this approach for osteosarcoma remains relatively unexplored. In this review, we outline the mechanisms and status of immunotherapies currently in clinical trials as well as future therapies on the horizon, and discuss their potential application for osteosarcoma.

Targeted therapy for infants with diencephalic syndrome: A case report and review of management strategies.

Young children with emaciation caused by a hypothalamic glioma are considered to have diencephalic syndrome (DS), which is often poorly controlled with conventional treatment. We describe an infant with DS whose tumor progressed following chemotherapy. Biopsy was performed for molecular testing and demonstrated a BRAF fusion. Treatment with the MEK inhibitor trametinib for 18 months resulted in reduction of tumor size, normalization of his weight curve, and marked neurodevelopmental improvement. Our results build on earlier reports of using targeted agents for low-grade glioma, and we review the evolving management strategy for such patients in the era of precision medicine.

Consensus and controversies regarding the treatment of rhabdomyosarcoma.

Optimal treatment of rhabdomyosarcoma (RMS) requires multidisciplinary approach, incorporating chemotherapy with local control. Although current therapies are built on cooperative group trials, a comprehensive standard of care to guide clinical decision making has been lacking, especially for relapsed patients. Therefore, we assembled a panel of pediatric and adolescent and young adult sarcoma experts to develop treatment guidelines for managing RMS and to identify areas in which further research is needed. We created algorithms incorporating evidence-based care for patients with RMS, emphasizing the importance of clinical trials and close integration of all specialties involved in the care of these patients.

Detection of lymph node metastases in pediatric and adolescent/young adult sarcoma: Sentinel lymph node biopsy versus fludeoxyglucose positron emission tomography imaging-A prospective trial.

BACKGROUND: Lymph node metastases are an important cause of treatment failure for pediatric and adolescent/young adult (AYA) sarcoma patients. Nodal sampling is recommended for certain sarcoma subtypes that have a predilection for lymphatic spread. Sentinel lymph node biopsy (SLNB) may improve the diagnostic yield of nodal sampling, particularly when single-photon emission computed tomography/computed tomography (SPECT-CT) is used to facilitate anatomic localization. Functional imaging with positron emission tomography/computed tomography (PET-CT) is increasingly used for sarcoma staging and is a less invasive alternative to SLNB. To assess the utility of these 2 staging methods, this study prospectively compared SLNB plus SPECT-CT with PET-CT for the identification of nodal metastases in pediatric and AYA patients. METHODS: Twenty-eight pediatric and AYA sarcoma patients underwent SLNB with SPECT-CT. The histological findings of the excised lymph nodes were then correlated with preoperative PET-CT imaging. RESULTS: A median of 2.4 sentinel nodes were sampled per patient. No wound infections or chronic lymphedema occurred. SLNB identified tumors in 7 of the 28 patients (25%), including 3 patients who had normal PET-CT imaging of the nodal basin. In contrast, PET-CT demonstrated hypermetabolic regional nodes in 14 patients, and this resulted in a positive predictive value of only 29%. The sensitivity and specificity of PET-CT for detecting histologically confirmed nodal metastases were only 57% and 52%, respectively. CONCLUSIONS: SLNB can safely guide the rational selection of nodes for biopsy in pediatric and AYA sarcoma patients and can identify therapy-changing nodal disease not appreciated with PET-CT. Cancer 2017;155-160. © 2016 American Cancer Society.

Early Lymphocyte Recovery and Outcome in Osteosarcoma.

BACKGROUND: Early lymphocyte recovery following chemotherapy has been associated with improved outcome in many cancers, including in one small study of osteosarcoma patients. MATERIALS AND METHODS: To confirm this finding, we retrospectively reviewed data from 53 patients with newly diagnosed osteosarcoma who had blood counts on day 14 (±1 d) following the first cycle of cisplatin and doxorubicin. RESULTS: The median absolute lymphocyte count (ALC) 14 days after starting the first cycle of chemotherapy (ALC-14) was 1990 cells/µL (range: 600 to 6470). For 32 patients with an ALC-14≥1800 cells/µL, the 5-year progression-free survival (PFS) was 69%, compared with 33% for patients with an ALC-14 of <1800 cell/µL (P=0.036). In multivariable analysis of factors including age, sex, metastatic disease, and favorable histologic response to induction chemotherapy, ALC-14 was significantly associated with PFS (P=0.0081) and overall survival (P=0.0131). The use of ALC-14 appears to further stratify PFS and overall survival among patients when grouped by histologic response. CONCLUSIONS: We confirmed that early lymphocyte recovery was associated with outcome in pediatric osteosarcoma. Although presumably reflecting immune-mediated tumor control, the precise mechanism for this is unclear. Further study of peripheral blood lymphocyte subpopulations in prospectively treated patients is underway.

Pilot study of propranolol premedication to reduce FDG uptake in brown adipose tissue on PET scans of adolescent and young adult oncology patients.

OBJECTIVE: Physiologic uptake of 18F-fluorodeoxyglucose (FDG) in brown adipose tissue (adipose tissue) of cancer patients may confound interpretation of positron emission tomography (PET) scans. Uptake in adipose tissue occurs in up to half of pediatric oncology patients undergoing PET scans, and is especially common in adolescents. adipose tissue is innervated by the sympathetic nervous system, and beta blockers such as propranolol have shown efficacy in reducing adipose tissue uptake on PET scans done in older adult oncology patients. PARTICIPANTS: Because propranolol may cause hypoglycemia or other side effects in fasting patients, we prospectively assessed the safety of a single dose of 20 mg propranolol in adolescent and young adult oncology patients undergoing FDG-PET imaging. METHODS: Ten patients (median age 18 years, range 14-24) received propranolol premedication prior to FDG-PET. RESULTS: No adverse effects or clinically significant changes in serum glucose, heart rate, or blood pressure were observed. Five of the 10 patients had adipose tissue identified on previous PET scans. However, following propranolol administration only, one patient had persistent uptake in adipose tissue. CONCLUSIONS: Propranolol was convenient and safe in fasting adolescent and young adult oncology patients undergoing PET scans. Larger studies are warranted to better define the effectiveness of this approach.

Phase II study of cixutumumab in combination with temsirolimus in pediatric patients and young adults with recurrent or refractory sarcoma: a report from the Children's Oncology Group.

BACKGROUND: The combined inhibition of insulin-growth factor type 1 receptor (IGF-1R) and the mammalian target of rapamycin (mTOR) has shown activity in preclinical models of pediatric sarcoma and in adult sarcoma patients. We evaluated the activity of the anti-IGF-1R antibody cixutumumab with the mTOR inhibitor temsirolimus in patients with relapsed or refractory Ewing sarcoma, osteosarcoma, rhabdomyosarcoma, and other soft tissue sarcoma, using the recommended dosages from a pediatric phase I trial. METHODS: Cixutumumab 6 mg/kg and temsirolimus 8 mg/m(2) were administered intravenously once weekly in 4-week cycles to patients <30 years. Temsirolimus was escalated to 10 mg/m(2) for subsequent cycles in patients who did not experience unacceptable first-cycle toxicity. A two-stage design was used to identify a response rate <10 or >35% for each tumor-specific cohort. Tumor tissue was analyzed by immunohistochemistry for potential biomarkers of response. RESULTS: Forty-three evaluable patients received a median of 2 cycles (range 1-7). No objective responses were observed, and 16% of patients were progression-free at 12 weeks. Dose-limiting toxicity was observed in 15 (16%) of 92 cycles. The most common toxicities were mucositis, electrolyte disturbances, and myelosuppression. The majority of patients receiving a second cycle were not eligible for temsirolimus escalation due to first-cycle toxicity. The lack of objective responses precluded correlation with tissue biomarkers. CONCLUSIONS: Despite encouraging preclinical data, the combination of cixutumumab and temsirolimus did not result in objective responses in this phase II trial of pediatric and young adults with recurrent or refractory sarcoma.

Preclinical evaluation of nanoparticle albumin-bound paclitaxel for treatment of pediatric bone sarcoma.

The combination of docetaxel and gemcitabine is frequently used to treat recurrent bone sarcoma. Nanoparticle albumin-bound paclitaxel (nab-paclitaxel) is less toxic and more active than docetaxel or paclitaxel for breast cancer patients. The combination of nab-paclitaxel and gemcitabine has preclinical synergy and is approved to treat pancreatic cancer. We observed growth inhibition and improved survival with nab-paclitaxel in a Ewing sarcoma xenograft, and activity was additive with gemcitabine in an osteosarcoma model. Primary Ewing sarcoma tumors expressed the transport protein SPARC, previously associated with nab-paclitaxel activity. These findings provide rationale for further evaluation of nab-paclitaxel with gemcitabine for bone sarcoma.

Comparison of oral aprepitant and intravenous fosaprepitant for prevention of chemotherapy-induced nausea and vomiting in pediatric oncology patients: a randomized phase III trial.

Background: Neurokinin-1 receptor antagonists have improved the management of chemotherapy-induced nausea and vomiting (CINV), but to date there has been no prospective comparison between oral aprepitant and intravenous fosaprepitant in pediatric oncology patients. Methods: Our study was a double-parallel study, and the distribution ratio was 1:1. Children aged 2-12 years who were undergoing moderate or highly emetogenic chemotherapy (MEC or HEC) were randomly assigned to receive ondansetron and dexamethasone combined with either a single dose of intravenous fosaprepitant (arm A), or 3 days of oral aprepitant (arm B). The primary outcome measure was the rate of complete response (CR) of CINV within the acute phase, defined as from the start through 24 hours after the last chemotherapy dose. Response during the delayed phase, overall response, and use of rescue antiemetics were also assessed. Results: We prospectively evaluated 108 eligible patients, including 55 receiving fosaprepitant. Study observations were made during a single cycle for each patient. The occurrence of CR in the acute phase was statistically higher for patients receiving fosaprepitant (95% vs. 79%, P=0.018<0.05). Modest differences were seen in CR rates during the delayed phase (71% vs. 66%, P=0.586), and overall response rate (69% vs. 57%, P=0.179). The use of antiemetic rescue medicines was similar between arms A (11%) and B (7%). Conclusions: Fosaprepitant produced more CRs of CINV in the acute phase than did aprepitant, although there were no statistical differences in delayed phase response, overall response, or use of rescue antiemetics. This study confirms the safety, efficacy, and potential advantages of fosaprepitant in reducing CINV in pediatric oncology patients. Trial Registration: ClinicalTrials.gov identifier: NCT04873284.

Genetic variation near GRB10 associated with bone growth and osteosarcoma risk in canine and human populations.

BACKGROUND: Canine and human osteosarcoma are similar in clinical presentation and tumor genomics. Giant breed dogs experience elevated osteosarcoma incidence, and taller stature remains a consistent risk factor for human osteosarcoma. Whether evolutionarily conserved genes contribute to both human and canine osteosarcoma predisposition merits evaluation. METHODS: A multi-center sample of childhood osteosarcoma patients and controls underwent genome-wide genotyping and imputation. Ancestry-adjusted SNP associations were calculated within each dataset using logistic regression, then meta-analyzed across the three datasets, totaling 1091 patients and 3026 controls. Ten regions previously associated with canine osteosarcoma risk were mapped to the human genome, spanning ∼6 Mb. We prioritized association testing of 5985 human SNPs mapping to candidate osteosarcoma risk regions detected in Irish wolfhounds, the largest dog breed studied. Secondary analyses explored 6289 additional human SNPs mapping to candidate osteosarcoma risk regions identified in Rottweilers and greyhounds. RESULTS: Fourteen SNPs were associated with human osteosarcoma risk after adjustment for multiple comparisons, all within a 42 kb region of human Chromosome 7p12.1. The lead variant was rs17454681 (OR=1.25, 95 %CI: 1.12-1.39; P=4.1×10-5), and independent risk variants were not observed in conditional analyses. While the associated region spanned 2.1 Mb and contained eight genes in Irish wolfhounds, associations were localized to a 50-fold smaller region of the human genome and strongly implicate GRB10 (growth factor receptor-bound protein 10) in canine and human osteosarcoma predisposition. PheWAS analysis in UK Biobank data identified noteworthy associations of the rs17454681 risk allele with varied measures of height and pubertal timing. CONCLUSIONS: Our comparative oncology analysis identified a novel human osteosarcoma risk allele near GRB10, a growth inhibitor that suppresses activated receptor tyrosine kinases including IGF1R, PDGFRB, and EGFR. Epidemiologists may benefit from leveraging cross-species comparisons to identify haplotypes in highly susceptible but genetically homogenous populations of domesticated animals, then fine-mapping these associations in diverse human populations.

Assessment of minimal residual disease in ewing sarcoma.

Advances in molecular pathology now allow for identification of rare tumor cells in cancer patients. Identification of this minimal residual disease is particularly relevant for Ewing sarcoma, given the potential for recurrence even after complete remission is achieved. Using RT-PCR to detect specific tumor-associated fusion transcripts, otherwise occult tumor cells are found in blood or bone marrow in 20-30% of Ewing sarcoma patients, and their presence is associated with inferior outcomes. Although RT-PCR has excellent sensitivity and specificity for identifying tumor cells, technical challenges may limit its widespread applicability. The use of flow cytometry to identify tumor-specific antigens is a recently described method that may circumvent these difficulties. In this manuscript, we compare the advantages and drawbacks of these approaches, present data on a third method using fluorescent in situ hybridization, and discuss issues affecting the further development of these strategies.

In situ mass spectrometry imaging reveals heterogeneous glycogen stores in human normal and cancerous tissues.

Glycogen dysregulation is a hallmark of aging, and aberrant glycogen drives metabolic reprogramming and pathogenesis in multiple diseases. However, glycogen heterogeneity in healthy and diseased tissues remains largely unknown. Herein, we describe a method to define spatial glycogen architecture in mouse and human tissues using matrix-assisted laser desorption/ionization mass spectrometry imaging. This assay provides robust and sensitive spatial glycogen quantification and architecture characterization in the brain, liver, kidney, testis, lung, bladder, and even the bone. Armed with this tool, we interrogated glycogen spatial distribution and architecture in different types of human cancers. We demonstrate that glycogen stores and architecture are heterogeneous among diseases. Additionally, we observe unique hyperphosphorylated glycogen accumulation in Ewing sarcoma, a pediatric bone cancer. Using preclinical models, we correct glycogen hyperphosphorylation in Ewing sarcoma through genetic and pharmacological interventions that ablate in vivo tumor growth, demonstrating the clinical therapeutic potential of targeting glycogen in Ewing sarcoma.

Accuracy of central neuro-imaging review of DIPG compared with histopathology in the International DIPG Registry.

BACKGROUND: Diffuse intrinsic pontine glioma (DIPG) remains a clinico-radiologic diagnosis without routine tissue acquisition. Reliable imaging distinction between DIPG and other pontine tumors with potentially more favorable prognoses and treatment considerations is essential. METHODS: Cases submitted to the International DIPG registry (IDIPGR) with histopathologic and/or radiologic data were analyzed. Central imaging review was performed on diagnostic brain MRIs (if available) by two neuro-radiologists. Imaging features suggestive of alternative diagnoses included nonpontine origin, <50% pontine involvement, focally exophytic morphology, sharply defined margins, and/or marked diffusion restriction throughout. RESULTS: Among 286 patients with pathology from biopsy and/or autopsy, 23 (8%) had histologic diagnoses inconsistent with DIPG, most commonly nondiffuse low-grade gliomas and embryonal tumors. Among 569 patients with centrally-reviewed diagnostic MRIs, 40 (7%) were classified as non-DIPG, alternative diagnosis suspected. The combined analysis included 151 patients with both histopathology and centrally-reviewed MRI. Of 77 patients with imaging classified as characteristic of DIPG, 76 (99%) had histopathologic diagnoses consistent with DIPG (infiltrating grade II-IV gliomas). Of 57 patients classified as likely DIPG with some unusual imaging features, 55 (96%) had histopathologic diagnoses consistent with DIPG. Of 17 patients with imaging features suggestive of an alternative diagnosis, eight (47%) had histopathologic diagnoses inconsistent with DIPG (remaining patients were excluded due to nonpontine tumor origin). Association between central neuro-imaging review impression and histopathology was significant (p < 0.001), and central neuro-imaging impression was prognostic of overall survival. CONCLUSIONS: The accuracy and important role of central neuro-imaging review in confirming the diagnosis of DIPG is demonstrated.

Chemoresistant hepatoblastoma in a patient with mosaic trisomy 18 treated with orthotopic liver transplantation.

We present a 9-month-old male with mosaic trisomy 18 with a right hepatic lobe mass. The tumor was completely resected and identified as pure fetal histology hepatoblastoma but contained increased mitotic activity. Adjuvant chemotherapy consisted of cisplatin, vincristine, and 5-fluorouracil. After the first and fourth cycles of chemotherapy, recurrent tumor developed. The patient underwent rescue orthotopic liver transplantation, and is currently alive without evidence of hepatoblastoma 28 months after transplantation. This report demonstrates the use of orthotopic liver transplantation in a child with mosaic trisomy 18 and hepatoblastoma.

Use of sentinel node biopsy for staging parameningeal rhabdomyosarcoma.

Identification of nodal involvement is important for treatment planning in patients with rhabdomyosarcoma, and is facilitated by sentinel node biopsy. Although it is employed primarily for extremity tumors, we report using sentinel node biopsy in a patient with parameningeal rhabdomyosarcoma arising in the ethmoid sinus. Lymphoscintigraphy with single photon emission computed tomography following injection of tracer at the tumor site helped identify contralateral cervical node involvement not previously recognized by physical exam, cross sectional imaging, or other functional imaging. This case demonstrates how information from sentinel node identification and biopsy can change therapy recommendations in patients with parameningeal rhabdomyosarcoma.

A welcome surprise: nodular fasciitis presenting as soft tissue sarcoma.

A 15-year-old boy presented with a growing mass on the anterior chest wall. History, clinical examination, and preoperative imaging studies were consistent with soft tissue sarcoma. He underwent open biopsy, and the intraoperative pathology diagnosis of nodular fasciitis resulted in performance of a lesional excision, rather than a potentially morbid wide resection. Nodular fasciitis is a rare but important soft tissue lesion, which can be easily confused with sarcoma. The possibility of benign etiologies for soft tissue masses should be considered when planning surgical options, even when preoperative imaging studies suggest more aggressive lesions.