Histologic type predicts disparate outcomes in pediatric hepatocellular neoplasms: A Pediatric Surgical Oncology Research Collaborative study.

BACKGROUND: Hepatocellular carcinoma (HCC) is a rare cancer in children, with various histologic subtypes and a paucity of data to guide clinical management and predict prognosis. METHODS: A multi-institutional review of children with hepatocellular neoplasms was performed, including demographic, staging, treatment, and outcomes data. Patients were categorized as having conventional HCC (cHCC) with or without underlying liver disease, fibrolamellar carcinoma (FLC), and hepatoblastoma with HCC features (HB-HCC). Univariate and multivariate analyses identified predictors of mortality and relapse. RESULTS: In total, 262 children were identified; and an institutional histologic review revealed 110 cHCCs (42%; 69 normal background liver, 34 inflammatory/cirrhotic, 7 unknown), 119 FLCs (45%), and 33 HB-HCCs (12%). The authors observed notable differences in presentation and behavior among tumor subtypes, including increased lymph node involvement in FLC and higher stage in cHCC. Factors associated with mortality included cHCC (hazard ratio [HR], 1.63; P = .038), elevated α-fetoprotein (HR, 3.1; P = .014), multifocality (HR, 2.4; P < .001), and PRETEXT (pretreatment extent of disease) stage IV (HR, 5.76; P < .001). Multivariate analysis identified increased mortality in cHCC versus FLC (HR, 2.2; P = .004) and in unresectable tumors (HR, 3.4; P < .001). Disease-free status at any point predicted survival. CONCLUSIONS: This multi-institutional, detailed data set allowed a comprehensive analysis of outcomes for children with these rare hepatocellular neoplasms. The current data demonstrated that pediatric HCC subtypes are not equivalent entities because FLC and cHCC have distinct anatomic patterns and outcomes in concert with their known molecular differences. This data set will be further used to elucidate the impact of histology on specific treatment responses, with the goal of designing risk-stratified algorithms for children with HCC. LAY SUMMARY: This is the largest reported granular data set on children with hepatocellular carcinoma. The study evaluates different subtypes of hepatocellular carcinoma and identifies key differences between subtypes. This information is pivotal in improving understanding of these rare cancers and may be used to improve clinical management and subsequent outcome in children with these rare malignancies.

Implications of Tumor Characteristics and Treatment Modality on Local Recurrence and Functional Outcomes in Children With Chest Wall Sarcoma: A Pediatric Surgical Oncology Research Collaborative Study.

OBJECTIVE: To determine the impact of tumor characteristics and treatment approach on (1) local recurrence, (2) scoliosis development, and (3) patient-reported quality of life in children with sarcoma of the chest wall. SUMMARY OF BACKGROUND DATA: Children with chest wall sarcoma require multimodal therapy including chemotherapy, surgery, and/or radiation. Despite aggressive therapy which places them at risk for functional impairment and scoliosis, these patients are also at significant risk for local recurrence. METHODS: A multi-institutional review of 175 children (median age 13 years) with chest wall sarcoma treated at seventeen Pediatric Surgical Oncology Research Collaborative institutions between 2008 and 2017 was performed. Patient-reported quality of life was assessed prospectively using PROMIS surveys. RESULTS: The most common diagnoses were Ewing sarcoma (67%) and osteosarcoma (9%). Surgical resection was performed in 85% and radiation in 55%. A median of 2 ribs were resected (interquartile range = 1-3), and number of ribs resected did not correlate with margin status ( P = 0.36). Local recurrence occurred in 23% and margin status was the only predictive factor(HR 2.24, P = 0.039). With a median follow-up of 5 years, 13% developed scoliosis (median Cobb angle 26) and 5% required corrective spine surgery. Scoliosis was associated with posteriorrib resection (HR 8.43; P= 0.003) and increased number of ribs resected (HR 1.78; P = 0.02). Overall, patient-reported quality of life is not impaired after chest wall tumor resection. CONCLUSIONS: Local recurrence occurs in one-quarter of children with chest wall sarcoma and is independent of tumor type. Scoliosis occurs in 13% of patients, but patient-reported quality of life is excellent.

Prospective pan-cancer germline testing using MSK-IMPACT informs clinical translation in 751 patients with pediatric solid tumors.

The spectrum of germline predisposition in pediatric cancer continues to be realized. Here we report 751 solid tumor patients who underwent prospective matched tumor-normal DNA sequencing and downstream clinical use (clinicaltrials.gov NCT01775072). Germline pathogenic and likely pathogenic (P/LP) variants were reported. One or more P/LP variants were found in 18% (138/751) of individuals when including variants in low, moderate, and high penetrance dominant or recessive genes, or 13% (99/751) in moderate and high penetrance dominant genes. 34% of high or moderate penetrance variants were unexpected based on the patient's diagnosis and previous history. 76% of patients with positive results completed a clinical genetics visit, and 21% had at least one relative undergo cascade testing as a result of this testing. Clinical actionability additionally included screening, risk reduction in relatives, reproductive use, and use of targeted therapies. Germline testing should be considered for all children with cancer.

Extracellular vesicle and particle isolation from human and murine cell lines, tissues, and bodily fluids.

We developed a modified protocol, based on differential ultracentrifugation (dUC), to isolate extracellular vesicles and particles (specifically exomeres) (EVPs) from various human and murine sources, including cell lines, surgically resected tumors and adjacent tissues, and bodily fluids, such as blood, lymphatic fluid, and bile. The diversity of these samples requires robust and highly reproducible protocols and refined isolation technology, such as asymmetric-flow field-flow fractionation (AF4). Our isolation protocol allows for preparation of EVPs for various downstream applications, including proteomic profiling. For complete details on the use and execution of this protocol, please refer to Hoshino et al. (2020).

Comprehensive Molecular Profiling of Desmoplastic Small Round Cell Tumor.

Desmoplastic small round cell tumor (DSRCT) is characterized by the EWSR1-WT1 t(11;22) (p13:q12) translocation. Few additional putative drivers have been identified, and research has suffered from a lack of model systems. Next-generation sequencing (NGS) data from 68 matched tumor-normal samples, whole-genome sequencing data from 10 samples, transcriptomic and affymetrix array data, and a bank of DSRCT patient-derived xenograft (PDX) are presented. EWSR1-WT1 fusions were noted to be simple, balanced events. Recurrent mutations were uncommon, but were noted in TERT (3%), ARID1A (6%), HRAS (5%), and TP53 (3%), and recurrent loss of heterozygosity (LOH) at 11p, 11q, and 16q was identified in 18%, 22%, and 34% of samples, respectively. Comparison of tumor-normal matched versus unmatched analysis suggests overcalling of somatic mutations in prior publications of DSRCT NGS data. Alterations in fibroblast growth factor receptor 4 (FGFR4) were identified in 5 of 68 (7%) of tumor samples, whereas differential overexpression of FGFR4 was confirmed orthogonally using 2 platforms. PDX models harbored the pathognomic EWSR1-WT1 fusion and were highly representative of corresponding tumors. Our analyses confirm DSRCT as a genomically quiet cancer defined by the balanced translocation, t(11;22)(p13:q12), characterized by a paucity of secondary mutations but a significant number of copy number alterations. Against this genomically quiet background, recurrent activating alterations of FGFR4 stood out, and suggest that this receptor tyrosine kinase, also noted to be highly expressed in DSRCT, should be further investigated. Future studies of DSRCT biology and preclinical therapeutic strategies should benefit from the PDX models characterized in this study. IMPLICATIONS: These data describe the general quiescence of the desmoplastic small round cell tumor (DSRCT) genome, present the first available bank of DSRCT model systems, and nominate FGFR4 as a key receptor tyrosine kinase in DSRCT, based on high expression, recurrent amplification, and recurrent activating mutations.

Current surgical management of children with osteosarcoma and pulmonary metastatic disease: A survey of the American Pediatric Surgical Association.

BACKGROUND: Rates of long-term survival for children with pulmonary metastatic osteosarcoma are low, and complete surgical resection of all visible pulmonary metastases is necessary for long term survival. Surgical approaches for metastasectomy include thoracotomy and thoracoscopy, with the approach chosen influenced by training and institutional bias. Thoracotomy with manual palpation of lung surfaces can identify nodules not seen on preoperative imaging, but no clear survival benefit has been demonstrated compared to complete thoracoscopic resection of all visible nodules. METHODS: All member of the American Pediatric Surgical Association were surveyed, and 204 members responded. RESULTS: Thoracoscopy was the preferred approach of 34% of surgeons for patients with 3 unilateral nodules but only 21% for those with 5 unilateral nodules. Hospital volume did not correlate with operative approach. Localization strategies are used by 37% of surgeons who prefer thoracotomy and 64% who prefer thoracoscopy. Importantly, the vast majority of responding surgeons (84%) expressed a willingness to participate in a randomized controlled trial of thoracotomy versus thoracoscopy. CONCLUSION: Findings of this survey of North American pediatric surgeons confirm both the need for, and interest in, a prospective trial to define optimal surgical management of children with osteosarcoma with limited pulmonary metastasis. LEVEL OF EVIDENCE: V.

Suboptimal outcome for patients with biliary rhabdomyosarcoma treated on low-risk clinical trials: A report from the Children's Oncology Group.

BACKGROUND: Biliary rhabdomyosarcoma (RMS) is the most common biliary tumor in children. The biliary tract is classified as a favorable primary site. Therefore, patients with localized biliary RMS were included in two consecutive low-risk studies, D9602 and ARST0331, by the Children's Oncology Group (COG). The outcome for these patients treated with low-risk therapy has not been reported. PROCEDURE: Patients with biliary RMS enrolled on COG low-risk trials D9602 or ARST0331 were analyzed. All patients received systemic chemotherapy and those with Group II (microscopic residual) or Group III (macroscopic residual) disease received 36-50.4 Gy adjuvant radiotherapy (RT). Delayed primary excision (DPE) was allowed on both studies. RESULTS: Seventeen patients with biliary RMS were treated on D9602 (n = 7) or ARST0331 (n = 10). Median age was 3.5 years (range 1.7-10.3). Ten (59%) patients had tumors >5 cm and 14 (82%) had Group III disease. Fifteen (88%) patients received RT. The 5-year event-free survival (EFS) and overall survival (OS) were 70.6% (95% confidence interval [CI]: 46.9-94.3%) and 76.5% (95% CI: 54.6-98.4%), respectively. The majority of patients (80%) who received RT did not have disease recurrence while both patients who did not receive RT had local relapse. Five (36%) of 14 patients with Group III disease underwent DPE; two experienced a local relapse. In the nine patients without DPE, two developed local relapse. CONCLUSIONS: Patients with localized biliary RMS treated on low-risk studies had suboptimal outcomes. These patients may benefit from therapy on intermediate-risk studies.

Appendectomy Versus Observation for Appendicitis in Neutropenic Children With Cancer.

BACKGROUND: Optimal management of neutropenic appendicitis (NA) in children undergoing cancer therapy remains undefined. Management strategies include upfront appendectomy or initial nonoperative management. We aimed to characterize the effect of management strategy on complications and length of stay (LOS) and describe implications for chemotherapy delay or alteration. METHODS: Sites from the Pediatric Surgery Oncology Research Collaborative performed a retrospective review of children with NA over a 6-year period. RESULTS: Sixty-six children, with a median age of 11 years (range 1-17), were identified with NA while undergoing cancer treatment. The most common cancer diagnoses were leukemia (62%) and brain tumor (12%). Upfront appendectomy was performed in 41% of patients; the remainder had initial nonoperative management. Rates of abscess or perforation at diagnosis were equivalent in the groups (30% vs 24%; P = .23). Of patients who had initial nonoperative management, 46% (17 of 37) underwent delayed appendectomy during the same hospitalization. Delayed appendectomy was due to failure of initial nonoperative management in 65% (n = 11) and count recovery in 35% (n = 6). Cancer therapy was delayed in 35% (n = 23). Initial nonoperative management was associated with a delay in cancer treatment (46% vs. 22%, P = .05) and longer LOS (29 vs 12 days; P = .01). Patients who had initial nonoperative management and delayed appendectomy had a higher rate of postoperative complications (P < .01). CONCLUSIONS: In pediatric patients with NA from oncologic treatment, upfront appendectomy resulted in lower complication rates, reduced LOS, and fewer alterations in chemotherapy regimens compared to initial nonoperative management.

Survival and Scoliosis Following Resection of Chest Wall Tumors in Children and Adolescents: A Single-center Retrospective Analysis.

OBJECTIVE: We reviewed our experience with pediatric chest wall tumors (CWTs) to identify variables associated with survival, scoliosis development, and need for corrective scoliosis surgery. BACKGROUND: Chest wall neoplasms in children or adolescents are rare. Consequently, there are few large series that detail survival or quality of life indicators, like scoliosis. METHODS: Medical records were reviewed for all chest wall resections for primary and metastatic CWT performed from October 1, 1986 to September 30, 2016 on patients 21 years or younger at diagnosis. Kaplan-Meier distributions were compared using the log-rank test. Variables correlated with survival, scoliosis development, or need for corrective surgeries were analyzed using competing-risk analysis. RESULTS: Seventy-six cases [57 (75%) primary, 19 (25%) metastatic] were identified. Median age at diagnosis was 15.6 years (range: 0.5-21 years). Tumor types were Ewing sarcoma family tumors (54%), other soft tissue sarcomas (21%), osteosarcoma (11%), rhabdomyosarcoma (7%), and other (8%). A median of 3 (range: 1-5) contiguous ribs were resected. Surgical reconstruction included composite Marlex mesh and methyl-methacrylate, Gore-Tex, or primary closure in 57%, 28%, and 14% of procedures, respectively. Overall 5-year survival was 61% (95% confidence interval: 50%-75%). Scoliosis developed in 19 (25%) patients; 6 patients required corrective surgery. Variables associated with overall survival were the presence of metastatic disease at diagnosis, and whether the chest tumor itself was a primary or metastatic lesion. Younger age at chest wall resection was associated with the need for corrective surgery in patients who developed scoliosis. CONCLUSIONS: Among pediatric and adolescent patients with CWTs, survival depends primarily on the presence of metastases. Age, type of chest wall reconstruction, and tumor size are not associated with scoliosis development. Among patients who develop scoliosis, younger patients are more likely to require corrective surgery.

Pneumonectomy for Pediatric Tumors-a Pediatric Surgical Oncology Research Collaborative Study.

OBJECTIVE: To describe utilization and long-term outcomes of pneumonectomy in children and adolescents with cancer. SUMMARY BACKGROUND DATA: Pneumonectomy in adults is associated with significant morbidity and mortality. Little is known about the indications and outcomes of pneumonectomy for pediatric tumors. METHODS: The Pediatric Surgical Oncology Research Collaborative (PSORC) identified pediatric patients <21 years of age who underwent pneumonectomy from 1990 to 2017 for primary or metastatic tumors at 12 institutions. Clinical information was collected; outcomes included operative complications, long-term function, recurrence, and survival. Univariate log rank, and multivariable Cox analyses determined factors associated with survival. RESULTS: Thirty-eight patients (mean 12 ±â€Š6 yrs) were identified; median (IQR) follow-up was 19 (5-38) months. Twenty-six patients (68%) underwent pneumonectomy for primary tumors and 12 (32%) for metastases. The most frequent histologies were osteosarcoma (n = 6), inflammatory myofibroblastic tumors (IMT; n = 6), and pleuropulmonary blastoma (n = 5). Median postoperative ventilator days were 0 (0-1), intensive care 2 (1-3), and hospital 8 (5-16). Early postoperative complications occurred in 10 patients including 1 death. Of 25 (66%) patients alive at 1 year, 15 reported return to preoperative pulmonary status. All IMT patients survived while all osteosarcoma patients died during follow-up. On multivariable analysis, metastatic indications were associated with nonsurvival (HR = 3.37, P = 0.045). CONCLUSION: This is the largest review of children who underwent pneumonectomy for cancer. There is decreased procedure-related morbidity and mortality than reported for adults. Survival is worse with preoperative metastatic disease, especially osteosarcoma.

Evolving applications of fluorescence guided surgery in pediatric surgical oncology: A practical guide for surgeons.

Fluorescence-guided surgery (FGS) is an increasingly available and popular method of visual field augmentation. The basic premise of FGS entails injection of fluorescent indocyanine green (ICG) and subsequent detection with a near-infrared (NIR) camera. For pediatric surgical oncologists, FGS remains experimental but is a promising modality for identifying tumor margins, locating metastases, performing sentinel lymph node biopsies, protecting peritumoral structures of interest, and facilitating reconstruction. Familiarity with basic ICG pharmacokinetics and NIR detection optics is critical for surgeons wishing to judiciously use FGS, as its success is firmly grounded in a thorough understanding of its capabilities and limitations. In this practical guide, we outline several well-described and innovative FGS applications by disease type, including their methods of administration, modes of detection, and typical ICG dosing paradigms. LEVEL OF EVIDENCE: V.

Thoracoscopy vs thoracotomy for the management of metastatic osteosarcoma: A Pediatric Surgical Oncology Research Collaborative Study.

Complete surgical resection of pulmonary metastatic disease in patients with osteosarcoma is crucial to long-term survival. Open thoracotomy allows palpation of nodules not identified on imaging but the impact on survival is unknown. The objective of this study was to compare overall survival (OS) and pulmonary disease-free survival (DFS) in children who underwent thoracotomy vs thoracoscopic surgery for pulmonary metastasectomy. A multi-institutional collaborative group retrospectively reviewed 202 pediatric patients with osteosarcoma who underwent pulmonary metastasectomy by thoracotomy (n = 154) or thoracoscopy (n = 48). Results were analyzed by Kaplan-Meier survival estimates and multivariate Cox proportional hazard regression models. With median follow-up of 45 months, 135 (67.5%) patients had a pulmonary relapse and 95 (47%) patients were deceased. Kaplan-Meier analysis showed no significant difference in 5-year pulmonary DFS (25% vs 38%; P = .18) or OS (49% vs 42%, P = .37) between the surgical approaches of thoracotomy and thoracoscopy. In Cox regression analysis controlling for other factors impacting outcome, there was a significantly increased risk of mortality (HR 2.11; P = .027; 95% CI 1.09-4.09) but not pulmonary recurrence (HR 0.96; P = .90; 95% CI 0.52-1.79) with a thoracoscopic approach. However, in the subset analysis limited to patients with oligometastatic disease, thoracoscopy had no increased risk of mortality (HR 1.16; P = .62; 0.64-2.11). In conclusion, patients with metastatic osteosarcoma and limited pulmonary disease burden demonstrate comparable outcomes after thoracotomy and thoracoscopy for metastasectomy. While significant selection bias in these surgical cohorts limits the generalizability of the conclusions, clinical equipoise for a randomized clinical trial in patients with oligometastatic disease is supported.

B7H3-Directed Intraperitoneal Radioimmunotherapy With Radioiodinated Omburtamab for Desmoplastic Small Round Cell Tumor and Other Peritoneal Tumors: Results of a Phase I Study.

PURPOSE: Desmoplastic small round cell tumor (DSRCT), a rare sarcoma of adolescents/young adults primarily involving the peritoneum, has a long-term survival of < 20% despite aggressive multimodality treatment. B7H3 is expressed on DSRCT cell surface, providing a target for antibody-based immunotherapy. PATIENTS AND METHODS: In this phase I study, we evaluated the safety, pharmacokinetics, and biodistribution of intraperitoneal (IP) radioimmunotherapy (RIT) with the anti-B7H3 murine monoclonal antibody 131I-omburtamab in patients with DSRCT or other B7H3-expressing tumors involving the peritoneum. After thyroid blockade, patients received 131I-omburtamab as a single IP injection at escalated activities from 1.11 to 3.33/GBq/m2. A prior tracer dose of IP 74 MBq124I-omburtamab was used for radioimmuno-positron emission tomography imaging. Each injection was followed by IP saline infusion. RESULTS: Fifty-two patients (48, three, and one with DSRCT, peritoneal rhabdomyosarcoma, and Ewing sarcoma, respectively) received IP 131I-omburtamab administered on an outpatient basis. Maximum tolerated dose was not reached; there were no dose-limiting toxicities. Major related adverse events were transient: grade 4 neutropenia (n = 2 patients) and thrombocytopenia (n = 1), and grade 1 (10%) and grade 2 (52%) pain lasting < 2 hours related to saline infusion. Hypothyroidism was not observed, and antidrug antibody was elicited in 5%. Mean (± SD) projected peritoneal residence time was 22.4 ± 7.9 hours. Mean projected absorbed doses for 131I-omburtamab based on 124I-omburtamab dosimetry to normal organs were low and well within tolerable limits. More than 80% 131I remained protein bound in blood 66 hours after RIT. On the basis of peritoneal dose and feasibility for outpatient administration, the recommended phase II activity was established at 2.96 GBq/m2. Patients with DSRCT receiving standard whole-abdominal radiotherapy after RIT did not experience unexpected toxicity. CONCLUSION: IP RIT 131I-omburtamab was well tolerated with minimal toxicities. Radiation exposure to normal organs was low, making combination therapy with other anticancer therapies feasible.

Pancreaticoduodenectomy for the treatment of pancreatic neoplasms in children: A Pediatric Surgical Oncology Research Collaborative study.

BACKGROUND: To better characterize short-term and long-term outcomes in children with pancreatic tumors treated with pancreaticoduodenectomy (PD). METHODS: Patients 21 years of age or younger who underwent PD at Pediatric Surgical Oncology Collaborative (PSORC) hospitals between 1990 and 2017 were identified. Demographic, clinical information, and outcomes (operative complications, long-term pancreatic function, recurrence, and survival) were collected. RESULTS: Sixty-five patients from 18 institutions with a median age of 13 years (4 months-22 years) and a median (IQR) follow-up of 2.8 (4.3) years were analyzed. Solid pseudopapillary tumor of the pancreas (SPN) was the most common histology. Postoperative complications included pancreatic leak in 14% (n = 9), delayed gastric emptying in 9% (n = 6), marginal ulcer in one patient, and perioperative (30-day) death due to hepatic failure in one patient. Pancreatic insufficiency was observed in 32% (n = 21) of patients, with 23%, 3%, and 6% with exocrine, or endocrine insufficiencies, or both, respectively. Children with SPN and benign neoplasms all survived. Overall, there were 14 (22%) recurrences and 11 deaths (17%). Univariate analysis revealed non-SPN malignant tumor diagnosis, preoperative vascular involvement, intraoperative transfusion requirement, pathologic vascular invasion, positive margins, and need for neoadjuvant chemotherapy as risk factors for recurrence and poor survival. Multivariate analysis only revealed pathologic vascular invasion as a risk factor for recurrence and poor survival. CONCLUSION: This is the largest series of pediatric PD patients. PD is curative for SPN and benign neoplasms. Pancreatic insufficiency is the most common postoperative complication. Outcome is primarily associated with histology.

Minimally invasive surgery for pediatric renal tumors: A systematic review by the APSA Cancer Committee.

Minimally invasive nephrectomy is performed routinely for adult renal tumors and for many benign pediatric conditions. Although open radical nephroureterectomy remains the standard of care for Wilms tumor and most pediatric renal malignancies, there are an increasing number of reports of minimally invasive surgery (MIS) for those operations as well. The APSA Cancer Committee performed a systematic review to better understand the risks and benefits of MIS in pediatric patients with renal tumors. METHODS: The search focused on MIS for renal tumors in children and followed the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) checklist. The initial database search identified 491 published articles, and after progressive review of abstracts and full-length articles, 19 were included in this review. RESULTS: There were two direct comparison studies where open surgery and MIS were compared. The remaining studies reported only on minimally invasive nephrectomy. Across all studies, there were a total of 151 patients, 126 of which had Wilms tumor and 10 patients had RCC. 104 patients had MIS, with 47 patients having open surgery. In the two studies in which open surgery and MIS were directly compared, more lymph nodes were harvested during open surgery (median = 2 (MIS) vs 5 (open); mean = 2.47 (MIS) vs 3.8 (open)). Many noncomparison studies reported the harvest of 2 of fewer lymph nodes for Wilms tumor. Several MIS patients were also noted to have intraoperative spill or positive margins. Survival between groups was similar. CONCLUSIONS: There is a lack of evidence to support MIS for pediatric renal tumors. This review demonstrates that lymph node harvest has been inadequate for MIS pediatric nephrectomy and there appears to be an increased risk for intraoperative spill. Survival data are similar between groups, but follow-up times were inconsistent and patient selection was clearly biased, with only small tumors being selected for MIS. TYPE OF STUDY: Review article. LEVEL OF EVIDENCE: III.

11p15.5 epimutations in children with Wilms tumor and hepatoblastoma detected in peripheral blood.

BACKGROUND: Constitutional or somatic mosaic epimutations are increasingly recognized as a mechanism of gene dysregulation resulting in cancer susceptibility. Beckwith-Wiedemann syndrome is the cancer predisposition syndrome most commonly associated with epimutation and is extremely variable in its phenotypic presentation, which can include isolated tumors. Because to the authors' knowledge large-scale germline DNA sequencing studies have not included methylation analysis, the percentage of pediatric cancer predisposition that is due to epimutations is unknown. METHODS: Germline methylation testing at the 11p15.5 locus was performed in blood for 24 consecutive patients presenting with hepatoblastoma (3 patients) or Wilms tumor (21 patients). RESULTS: Six individuals with Wilms tumor and 1 patient with hepatoblastoma were found to have low-level gain of methylation at imprinting control 1, and a child with hepatoblastoma was found to have loss of methylation at imprinting control 2. The loss of methylation at imprinting control 2 was found to be maternally inherited, despite not being associated with any detectable genomic alteration. CONCLUSIONS: Overall, 33% of patients (8 of 24 patients) with Wilms tumor or hepatoblastoma were found to have an epigenetic susceptibility that was detectable in the blood. It is interesting to note that low-level gain of methylation at imprinting control 1 predominantly was detected in females with bilateral Wilms tumors. Further studies in larger cohorts are needed to determine the efficacy of testing all patients with Wilms tumor or hepatoblastoma for 11p15.5 epimutations in the blood as part of DNA analysis because this hallmark of predisposition will not be detected by sequencing-based approaches and detecting a cancer predisposition may modify treatment.

Minimally invasive surgery for abdominal and thoracic neuroblastic tumors: A systematic review by the APSA Cancer committee.

BACKGROUND: Minimally invasive surgery has broad applicability to pediatric diseases, including pediatric cancer resection. Neuroblastic tumors of childhood are highly variable in presentation, and so careful selection of appropriate candidates for minimally invasive resection is paramount to achieving safe and durable surgical and oncological outcomes. METHODS: The American Pediatric Surgical Association Cancer Committee developed questions seeking to better define the role of minimally invasive surgery for neuroblastic tumors. A search using PubMed, Medline, Embase, Web of Science, ProQuest Dissertations, and Clinical Trials was performed for articles published from 1998 to 2018 in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines. RESULTS: The evidence identified is all retrospective in nature. Minimally invasive surgical resection of neuroblastic tumors is safe for carefully selected smaller (4-6 cm) image defined risk factor (IDRF)-negative abdominal tumors when oncologic principles are followed. Size is a less-well defined criterion for thoracic neuroblastic tumors. Open approaches for both abdominal and thoracic tumors may be preferable in the presence of IDRF's. CONCLUSION: Small tumors without IDRF's are reasonable candidates for minimally invasive resection. Surgical oncologic guidelines should be closely followed. The quality of data supporting this systematic review is poor and highlights the need for refinement in the study of such surgical techniques to improve knowledge and outcomes for patients with neuroblastic tumors. TYPE OF STUDY: Systematic Review. LEVEL OF EVIDENCE: Level III and Level IV.

A novel image-based system for risk stratification in patients with desmoplastic small round cell tumor.

BACKGROUND: Desmoplastic small round cell tumor (DSRCT) is an aggressive soft tissue sarcoma affecting children and young adults with 5-year overall survival (OS) of approximately 20%. Despite generally poor prognosis, long-term survival does occur. However, no evidence-based system exists to risk-stratify patients at diagnosis. METHODS: We retrospectively reviewed all DSRCT cases diagnosed at our institution between January 2000 and September 2016. Demographics, diagnostic imaging, and clinical data were reviewed. Univariate and multivariate Cox proportional hazard modeling was used to evaluate associations between imaging characteristics and OS. RESULTS: There were 130 patients (85% male; median age at presentation: 21.2 years) with confirmed DSRCT and sufficient imaging and clinical information for analysis. Median 5-year OS was 28% (95% CI: 19%-37%). In univariate analysis, shorter OS was associated with presence of liver lesions (hazard ratio [HR] 2.1, 95% CI: 1.28-3.45), chest lesions (HR 1.86, 95% CI: 1.11-3.1), and ascites (HR 1.69, 95% CI: 1.06-2.7). In multivariate analysis, liver involvement and ascites were predictive and were used to stratify risk (intermediate=no liver involvement or ascites; high=either liver involvement or ascites; very high=both liver involvement and ascites). Intermediate-risk patients had a 5-year survival of 61% (95% CI: 40%-76%) versus 16% (95% CI: 6%-29%) among high-risk patients and 8% (95% CI: 1%-29%) among very high risk patients. CONCLUSION: Patients with DSRCT can be risk-stratified at diagnosis based on specific imaging characteristics. TYPE OF STUDY: Retrospective study with no comparison group. LEVEL OF EVIDENCE: Level IV.

Prohibitin is a prognostic marker and therapeutic target to block chemotherapy resistance in Wilms' tumor.

Wilms' tumor is the most common type of childhood kidney cancer. To improve risk stratification and identify novel therapeutic targets for patients with Wilms' tumor, we used high-resolution mass spectrometry proteomics to identify urine tumor markers associated with Wilms' tumor relapse. We determined the urine proteomes at diagnosis of 49 patients with Wilms' tumor, non-Wilms' tumor renal tumors, and age-matched controls, leading to the quantitation of 6520 urine proteins. Supervised analysis revealed specific urine markers of renal rhabdoid tumors, kidney clear cell sarcomas, renal cell carcinomas as well as those detected in patients with cured and relapsed Wilms' tumor. In particular, urine prohibitin was significantly elevated at diagnosis in patients with relapsed as compared with cured Wilms' tumor. In a validation cohort of 139 patients, a specific urine prohibitin ELISA demonstrated that prohibitin concentrations greater than 998 ng/mL at diagnosis were significantly associated with ultimate Wilms' tumor relapse. Immunohistochemical analysis revealed that prohibitin was highly expressed in primary Wilms' tumor specimens and associated with disease stage. Using functional genetic experiments, we found that prohibitin was required for the growth and survival of Wilms' tumor cells. Overexpression of prohibitin was sufficient to block intrinsic mitochondrial apoptosis and to cause resistance to diverse chemotherapy drugs, at least in part by dysregulating factors that control apoptotic cytochrome c release from mitochondrial cristae. Thus, urine prohibitin may improve therapy stratification, noninvasive monitoring of treatment response, and early disease detection. In addition, therapeutic targeting of chemotherapy resistance induced by prohibitin dysregulation may offer improved therapies for patients with Wilms' and other relapsed or refractory tumors.

Fertility and hormone preservation and restoration for female children and adolescents receiving gonadotoxic cancer treatments: A systematic review.

BACKGROUND/PURPOSE: The purpose of this systematic review by the American Pediatric Surgical Cancer Committee was to summarize evidence from the current medical literature regarding fertility restoration and hormone replacement for female children and adolescents treated with gonadotoxic treatments. METHODS: Using PRISMA guidelines, questions were addressed by searching Medline, Cochrane, Embase Central and National clearing house databases using relevant search terms. Eligible studies included those that addressed ovarian tissue cryopreservation (OTC), oocyte harvest, ovarian transposition, and ovarian tissue auto-transplantation for females under the age of 20. Four reviewers independently screened studies for eligibility, extracted data and assessed the risk of bias. Study outcomes were summarized in a narrative synthesis. RESULTS: Two thousand two hundred seventy-six studies were identified by database search and manual review and 2185 were eliminated based on defined exclusion criteria. Ninety-one studies served as the basis for the systematic review. There were 1019 patients who underwent OTC with ages ranging from 0.4 to 20.4 years old, with 298 under the age of 13. Twenty patients aged 13-20 years old underwent successful oocyte harvest. Thirty-seven children underwent ovarian transposition as a means of fertility preservation. Eighteen patients underwent auto-transplantation of thawed ovarian cortical tissue that was harvested before the age of 21 years resulting in 10 live births. CONCLUSIONS: Clinically accepted and experimental fertility preservation options such as OTC, oocyte cryopreservation, and ovarian transposition are available to females aged 20 years and younger who are at risk for premature ovarian insufficiency and infertility due to gonadotoxic treatments. There is a large cohort of pediatric-aged patients, with a wide variety of diagnoses and treatments, who have undergone fertility preservation. Currently, fertility and hormone restoration experience for patients who were 20- years of age or younger at the time of fertility preservation remains limited. LEVEL OF EVIDENCE: IV.