Human serous cavity macrophages and dendritic cells possess counterparts in the mouse with a distinct distribution between species.

In mouse peritoneal and other serous cavities, the transcription factor GATA6 drives the identity of the major cavity resident population of macrophages, with a smaller subset of cavity-resident macrophages dependent on the transcription factor IRF4. Here we showed that GATA6+ macrophages in the human peritoneum were rare, regardless of age. Instead, more human peritoneal macrophages aligned with mouse CD206+ LYVE1+ cavity macrophages that represent a differentiation stage just preceding expression of GATA6. A low abundance of CD206+ macrophages was retained in C57BL/6J mice fed a high-fat diet and in wild-captured mice, suggesting that differences between serous cavity-resident macrophages in humans and mice were not environmental. IRF4-dependent mouse serous cavity macrophages aligned closely with human CD1c+CD14+CD64+ peritoneal cells, which, in turn, resembled human peritoneal CD1c+CD14-CD64- cDC2. Thus, major populations of serous cavity-resident mononuclear phagocytes in humans and mice shared common features, but the proportions of different macrophage differentiation stages greatly differ between the two species, and dendritic cell (DC2)-like cells were especially prominent in humans.

A novel maladaptive unfolded protein response as a mechanism for small bowel resection-induced liver injury.

The unfolded protein response (UPR) is a complex adaptive signaling pathway activated by the accumulation of misfolded proteins in the endoplasmic reticulum (ER). ER stress (ERS) triggers a cascade of responses that converge upon C/EBP homologous protein (CHOP) to drive inflammation and apoptosis. Herein, we sought to determine whether liver injury and fibrosis after small bowel resection (SBR) were mediated by a maladaptive hepatic ERS/UPR. C57BL/6 mice underwent 50% proximal SBR or sham operation. Markers of liver injury and UPR/ERS pathways were analyzed. These were compared with experimental groups including dietary fat manipulation, tauroursodeoxycholic acid (TUDCA) treatment, distal SBR, and global CHOP knockout (KO). At 10 wk, proximal SBR had elevated alanine aminotransferase/aspartate aminotransferase (ALT/AST) (P < 0.005) and greater hepatic tumor necrosis factor-α (TNFα) (P = 0.001) and collagen type 1 α1 (COL1A1) (P = 0.02) than shams. SBR livers had increased CHOP and p-eIF2α, but were absent in activating transcription factor 4 (ATF4) protein expression. Low-fat diet (LFD), TUDCA, and distal SBR groups had decreased liver enzymes, inflammation, and fibrosis (P < 0.05). Importantly, they demonstrated reversal of hepatic UPR with diminished CHOP and robust ATF4 signal. CHOP KO-SBR had decreased ALT but not AST compared with wild-type (WT)-SBR (P = 0.01, P = 0.12). There were no differences in TNFα and COL1A1 (P = 0.09, P = 0.50). SBR-induced liver injury, fibrosis is associated with a novel hepatic UPR/ERS response characterized by increased CHOP and decreased ATF4. LFD, TUDCA, and ileocecal resection rescued the hepatic phenotype and reversed the UPR pattern. Global CHOP KO only partially attenuated liver injury. This underscores the significance of disruptions to the gut/liver axis after SBR and potentiates targets to mitigate the progression of intestinal failure-associated liver disease.NEW & NOTEWORTHY The unfolded protein response (UPR) is a complex signaling cascade that converges upon C/EBP-homologous protein (CHOP). Under conditions of chronic cellular stress, the UPR shifts from homeostatic to proapoptotic leading to inflammation and cell death. Here, we provide evidence that small bowel resection-induced liver injury and fibrosis are mediated by a maladaptive hepatic UPR. Low-fat diet, TUDCA treatment, and ileocecal resection rescued the hepatic phenotype and reversed the UPR pattern.

Minimally invasive surgery to treat embryonal tumors of childhood.

Minimally invasive surgery (MIS) to resect primary and metastatic pediatric embryonal tumors offers the potential for reduced postoperative morbidity with smaller wounds, less pain, fewer surgical site infections, decreased blood loss, shorter hospital stays, and less disruption to treatment regimens. However, significant controversy surrounds the question of whether a high-fidelity oncologic resection of childhood embryonal tumors with gross total resection, negative margins, and appropriate lymph node sampling can be achieved through MIS. This review outlines the diverse applications of MIS to treat definitively pediatric embryonal malignancies, including this approach to metastatic deposits. It outlines specific patient populations and presentations that may be particularly amenable to the minimally invasive approach. This work further summarizes the current evidence supporting the efficacy of MIS to accomplish a definitive, oncologic resection without compromising relapse-free or overall survival. Finally, the review offers technical considerations to consider in order to achieve a safe and complete resection.

Enhancing Recovery After Kasai Portoenterostomy With Epidural Analgesia.

BACKGROUND: Biliary atresia (BA) is a rare obstructive cholangiopathy that presents in early infancy. The Kasai portoenterostomy (PE) improves survival with the native liver. Epidural analgesia is an appealing option to control pain in this fragile patient population, yet its safety, efficacy, and potential benefits remain unproven. METHODS: Patients undergoing PE for BA between 2001 and 2016 at a single institution were identified by ICD codes. Preoperative laboratories, procedure details, and recovery outcomes were reviewed retrospectively. Outcomes of interest were need for postoperative mechanical ventilation, pain scores, normalized opioid administration, return of bowel function, and length of hospital stay after PE. RESULTS: Of 47 infants undergoing PE for BA, 25 received epidural analgesia, and 22 did not. Infants with epidurals received less systemic opioids over the first 96 h postoperatively than those without (P < 0.001). Epidurals were associated with lower pain scores between 6 and 30 h postoperatively (P = 0.01 to 0.04), during which the highest median 6-h interval pain score was 0.2 (IQR 0-1.3) for patients with epidurals yet 2.1 (IQR 1.2-3.3) for patients without. Patients with epidurals (88%, n = 22) were more commonly extubated before leaving the operating room than those without (59%, n = 13; P = 0.02). No significant difference was observed in time to first bowel movement (P = 0.48) or first oral feed (P = 0.81). However, infants with epidurals had shorter hospital stays after PE than those without (6 d [IQR 5-7] versus 8 d [IQR 6.3-11], P = 0.01). No major complications were associated with epidural catheters. CONCLUSIONS: Epidural analgesia in patients undergoing PE for BA appears safe and effectively controls pain while minimizing the need for systemic opioids. Reduced need for mechanical ventilation postoperatively and shortened hospital stays serve as further evidence for using epidurals to enhance recovery after PE.

Surgery for chronic idiopathic constipation: pediatric and adult patients - a systematic review.

BACKGROUND: Chronic idiopathic constipation (CIC) is a substantial problem in pediatric and adult patients with similar symptoms and workup; however, surgical management of these populations differs. We systematically reviewed the trends and outcomes in the surgical management of CIC in pediatric and adult populations. METHODS: A literature search was performed using Ovid MEDLINE, Embase, Scopus, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov between January 1, 1995 and June 26, 2020. Clinical trials and retrospective and prospective studies of patients of any age with a diagnosis of CIC with data of at least 1 outcome of interest were selected. The interventions included surgical resection for constipation or antegrade continence enema (ACE) procedures. The outcome measures included bowel movement frequency, abdominal pain, laxative use, satisfaction, complications, and reinterventions. RESULTS: Adult patients were most likely to undergo resection (94%), whereas pediatric patients were more likely to undergo ACE procedures (96%) as their primary surgery. Both ACE procedures and resections were noted to improve symptoms of CIC; however, ACE procedures were associated with higher complication and reintervention rates. CONCLUSION: Surgical management of CIC in pediatric and adult patients differs with pediatric patients receiving ACE procedures and adults undergoing resections. The evaluation of resections and long-term ACE data in pediatric patients should be performed to inform patients and physicians whether an ACE is an appropriate procedure despite high complication and reintervention rates or whether resections should be considered as an initial approach for CIC.

Factors Associated with Non-Completion of a Pediatric Metabolic and Bariatric Surgery Program.

BACKGROUND: Childhood obesity is a devastating disease process disproportionately affecting minority and low-income populations. Though bariatric surgery leads to durable weight loss and reversal of multiple obesity-related comorbidities, only a small fraction of pediatric patients undergoes the procedure. We sought to identify factors associated with non-completion in a pediatric bariatric surgery program. METHODS: Retrospective review of consecutive patients ≤18-years-old referred to an academic adolescent bariatric surgery program between 2017 and 2022 (n = 20 completers, 40 non-completers) was completed. Demographics and medical and psychosocial histories were summarized by completion status. RESULTS: Of the 33% (20/60; 85% female, 30% racial minorities) who successfully completed the program, the median age was 16 years [IQR 16, 17]. The median age of non-completers was 16 years [IQR 15, 17] (55% female, 56% racial minorities). Non-completion was associated with male gender (15% of completers vs 45% of non-completers, p = 0.022), neighborhood income <150% poverty level (0 completers vs 17.5% of non-completers, p = 0.047), and presence of environmental or family stressors (22% of completers vs 65% of non-completers, p = 0.008). Though not statistically significant, non-completers tended to be racial minorities (p = 0.054). CONCLUSIONS: Non-completion of the bariatric surgery pathway was more prevalent among male patients from lower-income neighborhoods with significant environmental or family stressors. These patients also tended to be racial and ethnic minorities. The findings underscore the need for further investigation into barriers to pediatric bariatric surgery. LEVEL OF EVIDENCE: Level III.

Race and Ethnic Group Enrollment and Outcomes for Wilms Tumor: Analysis of the Current Era Children's Oncology Group Study, AREN03B2.

BACKGROUND: To review race and ethnic group enrollment and outcomes for Wilms tumor (WT) across all 4 risk-assigned therapeutic trials from the current era Children's Oncology Group Renal Tumor Biology and Risk Stratification Protocol, AREN03B2. STUDY DESIGN: For patients with WT enrolled in AREN03B2 (2006 to 2019), disease and biologic features, therapeutic study-specific enrollment, and event-free (EFS) and overall (OS) 4-year survival were compared between institutionally reported race and ethnic groups. RESULTS: Among 5,146 patients with WT, no statistically significant differences were detected between race and ethnic groups regarding subsequent risk-assigned therapeutic study enrollment, disease stage, histology, biologic factors, or overall EFS or OS, except the following variables: Black children were older and had larger tumors at enrollment, whereas Hispanic children had lower rates of diffuse anaplasia WT and loss of heterozygosity at 1p. The only significant difference in EFS or OS between race and ethnic groups was observed among the few children treated for diffuse anaplasia WT with regimen UH-1 and -2 on high-risk protocol, AREN0321. On this therapeutic arm only, Black children showed worse EFS (hazard ratio = 3.18) and OS (hazard ratio = 3.42). However, this finding was not replicated for patients treated with regimen UH-1 and -2 under AREN03B2 but not on AREN0321. CONCLUSIONS: Race and ethnic group enrollment appeared constant across AREN03B2 risk-assigned therapeutic trials. EFS and OS on these therapeutic trials when analyzed together were comparable regarding race and ethnicity. Black children may have experienced worse stage-specific survival when treated with regimen UH-1 and -2 on AREN0321, but this survival gap was not confirmed when analyzing additional high-risk AREN03B2 patients.

Intestinal adaptation and rehabilitation.

Massive intestinal resection is a regrettably necessary but life-saving intervention for progressive or fulminant necrotizing enterocolitis (NEC). However, the resultant short bowel syndrome (SBS) poses its own array of challenges and complications. Within hours of such an abrupt loss of intestinal length, the intestine begins to adapt. Our ability to understand this process of intestinal adaptation has proven critical in our ability to clinically treat the challenging problem of short bowel syndrome. This review first highlights key data relating to intestinal adaptation including structural and functional changes, biochemical regulation, and other factors affecting the magnitude of intestinal adaptation responses. We then focus on intestinal rehabilitation as it relates to strategies to enhance intestinal adaptation while meeting nutritional needs and preventing complications of parenteral nutrition.

Outcomes and Histological Variations of Neuroblastoma and Ganglioneuroblastoma with Paraneoplastic Syndromes.

BACKGROUND: Neuroblastomas are the most common extracranial solid malignancy in children with variable manifestations and complications depending on the presence of paraneoplastic syndromes. MATERIALS AND METHODS: We performed a single institution retrospective cohort study of all patients less than 18 years old diagnosed with neuroblastoma or ganglioneuroblastoma between January 2002 and July 2022. Patients were identified through the pathology and cancer registry and cross-referenced with pediatric records. Patient demographics, clinical presentation, treatment, and outcomes were collected. A univariate descriptive analysis of the collected data was conducted. RESULTS: In our study period, 130 children were diagnosed with neuroblastoma, and 15 were diagnosed with ganglioneuroblastoma. There were 12 children with a paraneoplastic syndrome identified, 8 with NBL and 4 with ganglioneuroblastoma (GNBL). The average age at diagnosis was 22 months. All but 1 underwent resection prior to treatment of paraneoplastic syndrome, and 4 children required neoadjuvant therapy. Neurological complications were the most common with 10 children (83%). The average time from symptom onset to diagnosis was 0.7 months. Eight children had complete resolution of their symptoms after treatment and resection, 2 children recently started treatment within a year, 1 had partial resolution, and 1 died during treatment. The presence of tumor-infiltrating lymphocytes occurred in 4 children with neurologic paraneoplastic syndromes. Six children had neuropil rich tumors. CONCLUSION: The histological profile of paraneoplastic syndromes of neuroblastoma and ganglioneuroblastoma and their treatment across a single institution can be highly variable. The presence of tumor-infiltrating lymphocytes and neuropil may have an impact on paraneoplastic pathology.

Intestinal Knockout of Peroxisome Proliferator-Activated Receptor-Alpha Affects Structural Adaptation but not Liver Injury Following Massive Enterectomy.

BACKGROUND: Resection-associated liver steatosis, injury, and fibrosis is a devastating complication associated with massive small bowel resection (SBR). Peroxisome proliferator-activated receptor-alpha (PPARα) is a key regulator of intestinal lipid transport and metabolism whose expression is selectively increased after SBR. Here we asked if attenuating intestinal PPARα signaling would prevent steatosis and liver injury after SBR. METHODS: Pparα was deleted selectively in adult mouse intestine using a tamoxifen-inducible Cre-LoxP breeding schema. Mice underwent 50% SBR. At 10 weeks post-operatively, metabolic phenotyping, body composition analysis, in vivo assessment of lipid absorption and intestinal permeability, and assessment of adaptation and liver injury was completed. RESULTS: Pparα intestinal knockout and littermate control mice were phenotypically similar in terms of weight trends and body composition after SBR. All mice demonstrated intestinal adaptation with increased villus height and crypt depth; however, Pparα intestinal knockout mice exhibited decreased villus growth at 10 weeks compared to littermate controls. Liver injury and fibrosis were similar between groups as assessed by serum AST and ALT levels, Sirius Red staining, and hepatic expression of Col1a1 and Acta2. CONCLUSIONS: Inducible intestinal deletion of Pparα influences structural adaptation but does not mitigate liver injury after SBR. These findings suggest that enterocyte PPARα signaling in adult mice is dispensable for resection-induced liver injury. The results are critical for understanding the contribution of intestinal lipid metabolic signaling pathways to the pathogenesis of hepatic injury associated with short bowel syndrome.

Exploiting embryonic niche conditions to grow Wilms tumor blastema in culture.

Introduction: Wilms Tumor (WT), or nephroblastoma, is the most common pediatric kidney cancer. Most WTs display a "favorable" triphasic histology, in which the tumor is comprised of blastemal, stromal, and epithelial cell types. Blastemal predominance after neoadjuvant chemotherapy or diffuse anaplasia ("unfavorable" histology; 5-8%) portend a worse prognosis. Blastema likely provide the putative cancer stem cells (CSCs), which retain molecular and histologic features characteristic of nephron progenitor cells (NPCs), within WTs. NPCs arise in the metanephric mesenchyme (MM) and populate the cap mesenchyme (CM) in the developing kidney. WT blastemal cells, like NPCs, similarly express markers, SIX2 and CITED1. Tumor xenotransplantation is currently the only dependable method to propagate tumor tissue for research or therapeutic screening, since efforts to culture tumors in vitro as monolayers have invariably failed. Therefore, a critical need exists to propagate WT stem cells rapidly and efficiently for high-throughput, real-time drug screening. Methods: Previously, our lab developed niche conditions that support the propagation of murine NPCs in culture. Applying similar conditions to WTs, we assessed our ability to maintain key NPC "stemness" markers, SIX2, NCAM, and YAP1, and CSC marker ALDHI in cells from five distinct untreated patient tumors. Results: Accordingly, our culture conditions maintained the expression of these markers in cultured WT cells through multiple passages of rapidly dividing cells. Discussion: These findings suggest that our culture conditions sustain the WT blastemal population, as previously shown for normal NPCs. As a result, we have developed new WT cell lines and a multi-passage in vitro model for studying the blastemal lineage/CSCs in WTs. Furthermore, this system supports growth of heterogeneous WT cells, upon which potential drug therapies could be tested for efficacy and resistance.

Race disparities in genetic alterations within Wilms tumor specimens.

BACKGROUND: Wilms tumor (WT) affects Black children disproportionately. Genetic aberrations within WT specimens that contribute to this disparity have not been reported. METHODS: The Therapeutically Applied Research to Generate Effective Treatments (TARGET) database was queried for WT patient and genomic features. Clinical and genetic variables were compared by race. RESULTS: Within the discovery set (enriched for adverse events; N = 94 White, 19 Black, 14 Other/unreported patients), Black children were more likely to present with advanced stage disease (p = 0.019). Within the validation set (primarily a random sampling of NWTS-5; N = 360 White, 92 Black, 72 Other/Unreported), Black children appeared older at diagnosis (p = 0.050), had decreased median follow-up time (p<0.0005) and were over-represented (17.4%) relative to the concurrent U.S. Census (12.8%). Among the 37 target genes sequenced, ACTB (p = 0.030) and DICER1 (p = 0.026) mutations were more common in Black patient specimens, whereas DGCR8 (p = 0.041) mutations were more common in White patient specimens. White patient specimens were more likely to contain one or multiple targeted mutations (p = 0.026). CONCLUSION: Within the TARGET database, Black children were over-represented and harbored WT specimens containing more frequent ACTB and DICER1 mutations. In contrast, WT from White children contained overall more mutations in targeted genes and specifically in DGCR8. LEVEL OF EVIDENCE: III.

Health disparities among tennessee pediatric renal tumor patients.

BACKGROUND/PURPOSE: Wilms tumor (WT) poses a cancer health disparity to black children globally, which has not been evaluated thoroughly for other pediatric renal cancers. We aimed to characterize health disparities among Tennessee children treated for any renal cancer. METHODS: The Tennessee Cancer Registry (TCR) was queried for patients ≤18 years having any renal cancer (n = 160). To clarify treatment and outcomes, we performed a retrospective cohort study of pediatric renal cancer patients in our institutional cancer registry (ICR; n = 121). Diagnoses in both registries included WT, Sarcoma/Other, and Renal Cell Carcinoma. Wilcoxon/Pearson, Kaplan-Meier, and logistic regression were completed. RESULTS: In both registries, WT comprised the most common renal cancer and youngest median age. Sarcoma was intermediate in frequency and age, and RCC was least common, having the oldest age (p < 0.001). In the TCR, black patients comprised 26% of all patients, presented more commonly with distant disease than white patients (37% v. 16%; p = 0.021), and showed worse overall survival (73% v. 89%; p = 0.018), while the ICR showed similar survival between race groups (92% v. 93%, p = 0.868). Sarcoma and metastases were independent predictors of death in both registries (p ≤ 0.002). CONCLUSIONS: Black children in Tennessee presented with more advanced disease and experienced worse survival when combining all renal cancer types, particularly RCC and Sarcoma. When treated at a comprehensive pediatric cancer center, these survival disparities appear diminished. TYPE OF STUDY: Prognostic study. LEVEL OF EVIDENCE: Level II (retrospective cohort).

Therapeutic laparoscopy for pediatric abdominal trauma.

BACKGROUND: For the surgical treatment of traumatic hollow viscus injuries, laparoscopy offers a potentially less morbid approach to open exploration among appropriately selected patients. This study aimed to evaluate utilization trends and efficacy of laparoscopy in the management of pediatric abdominal trauma. STUDY DESIGN: To gain both study granularity and power, our institutional trauma registry (2005-2017) and the National Trauma Data Bank (NTDB; 2010-2015) identified patients ≤18 years who required celiotomy for abdominal trauma. Injury mechanisms, patient characteristics, and hospital courses were compared between open and laparoscopic approaches. Unadjusted and adjusted statistical analyses were performed. RESULTS: Overall, data were similar among 393 institutional and 11,399 NTDB patients undergoing laparoscopic (n = 88, 22%; n = 1663, 16%) or open (n = 305, 78%; n = 9736, 85%) surgery for abdominal trauma. In both registries, laparoscopy was more commonly employed in younger (institutional p = 0.026; NTDB p < 0.001) female (p = 0.019; p < 0.001) patients having lower injury severity (p < 0.001) and blunt injuries (p = 0.031; p < 0.001). Laparoscopy was associated with fewer complications overall when adjusting for demographics and injury severity [institutional OR 0.25 (0.08-0.75), p = 0.013; NTDB OR 0.69 (0.55-0.88), p = 0.002]. An increase in utilization of MIS for pediatric abdominal trauma was detected over time (NTDB: r = 0.88, p = 0.02). CONCLUSION: For the management of pediatric abdominal trauma, laparoscopy was employed typically in younger, more stable, and female patients sustaining blunt injuries. Appropriately selected patients have similar or better outcomes to patients treated with laparotomy, with no increase in adverse events or missed injuries. Increased utilization of laparoscopy to manage abdominal trauma in children suggests greater acceptance of this approach. LEVEL OF EVIDENCE: Level III.

FXR1 expression domain in Wilms tumor.

BACKGROUND/PURPOSE: Wilms tumor (WT) is the most common childhood kidney cancer globally. Our prior unbiased proteomic screen of WT disparities revealed increased expression of Fragile X-Related 1 (FXR1) in Kenyan specimens where survival is dismal. FXR1 is an RNA-binding protein that associates with poor outcomes in multiple adult cancers. The aim of this study therefore was to validate and characterize the FXR1 expression domain in WT. METHODS: Quantitative FXR1 gene expression was compared between WT, adjacent, adult, and fetal kidney specimens. The cellular and subcellular expression domain of FXR1 was characterized across these tissues using immunoperoxidase staining. RNA-sequencing of FXR1 was performed from WT and other pediatric malignancies to examine its broader target potential. RESULTS: FXR1 was detected in all clinical WT specimens evaluated (n = 82), and as a result appeared independent of demographic, histology, or adverse event. Specific cytosolic staining was strongest in blastema, intermediate and variable in epithelia, and weakest in stroma. When present, areas of skeletal muscle differentiation stained strongly for FXR1. qPCR revealed increased FXR1 expression in WT compared to adult and adjacent kidney (p < 0.0002) but was similar to fetal kidney (p = 0.648). RNA-sequencing revealed expression of FXR1 in multiple pediatric tumors, greatest in rhabdomyosarcoma and WT. CONCLUSIONS: FXR1 was expressed consistently across this broad sampling of WT and most robustly in the primitive blastema. Notably, FXR1 labeled a specific self-renewing progenitor population of the fetal kidney.

Association between image-defined risk factors and neuroblastoma outcomes.

BACKGROUND: The current neuroblastoma (NBL) staging system employs image-defined risk factors (IDRFs) to assess numerous anatomic features, but the impact of IDRFs on surgical and oncologic outcomes is unclear. METHODS: The Vanderbilt Cancer Registry identified children treated for NBL from 2002 to 2017. Tumor volume (TV) and IDRFs were measured radiographically at diagnosis and before resection. Perioperative and oncologic outcomes were evaluated. RESULTS: At diagnosis of 106 NBL, 61% were IDRF positive. MYCN-amplified and undifferentiated NBL had more IDRFs than nonamplified and more differentiated tumors (p = 0.001 and p = 0.01). Of 86 NBLs resected, 43% were IDRF positive, which associated with higher stage, risk, and TV (each p < 0.001). The presence of IDRF at resection was also associated with increased blood loss (p < 0.001), longer operating times (p < 0.001), greater incidence of intraoperative complications (p = 0.03), more frequent ICU admissions postoperatively (p < 0.001), and longer hospital stays (p < 0.001). IDRF negative and positive tumors did not have significantly different rates of gross total resection (p = 0.2). Five-year relapse-free and overall survival was similar for IDRF negative and positive NBL (p = 0.9 and p = 0.8). CONCLUSIONS: IDRFs at diagnosis were associated with larger, less differentiated, advanced stage, and higher risk NBL and at resection with increased operative difficulty and perioperative morbidity. However, the frequency of gross total resection and patient survival after resection were not associated with the presence of IDRFs. TYPE OF STUDY: Retrospective cohort study. LEVEL OF EVIDENCE: Level III.

Minimally Invasive Surgery in Pediatric Surgical Oncology.

The application of minimally invasive surgery (MIS) to resect pediatric solid tumors offers the potential for reduced postoperative morbidity with smaller wounds, less pain, fewer surgical site infections, decreased blood loss, shorter hospital stays, and less disruption to treatment regimens. However, significant controversy surrounds the question of whether a high-fidelity oncologic resection of childhood cancers can be achieved through MIS. This review outlines the diverse applications of MIS to treat pediatric malignancies, up to and including definitive resection. This work further summarizes the current evidence supporting the efficacy of MIS to accomplish a definitive, oncologic resection as well as appropriate patient selection criteria for the minimally invasive approach.

Biological Drivers of Wilms Tumor Prognosis and Treatment.

Prior to the 1950s, survival from Wilms tumor (WT) was less than 10%. Today, a child diagnosed with WT has a greater than 90% chance of survival. These gains in survival rates from WT are attributed largely to improvements in multimodal therapy: Enhanced surgical techniques leading to decreased operative mortality, optimization of more effective chemotherapy regimens (specifically, dactinomycin and vincristine), and inclusion of radiation therapy in treatment protocols. More recent improvements in survival, however, can be attributed to a growing understanding of the molecular landscape of Wilms tumor. Particularly, identification of biologic markers portending poor prognosis has facilitated risk stratification to tailor therapy that achieves the best possible outcome with the least possible toxicity. The aim of this review is to (1) outline the specific biologic markers that have been associated with prognosis in WT and (2) provide an overview of the current use of biologic and other factors to stratify risk and assign treatment accordingly.

Maintaining oncologic integrity with minimally invasive resection of pediatric embryonal tumors.

BACKGROUND: Embryonal tumors arise typically in infants and young children and are often massive at presentation. Operative resection is a cornerstone in the multimodal treatment of embryonal tumors but potentially disrupts therapeutic timelines. When used appropriately, minimally invasive surgery can minimize treatment delays. The oncologic integrity and safety attainable with minimally invasive resection of embryonal tumors, however, remains controversial. METHODS: Query of the Vanderbilt Cancer Registry identified all children treated for intracavitary, embryonal tumors during a 15-year period. Tumors were assessed radiographically to measure volume (mL) and image-defined risk factors (neuroblastic tumors only) at time of diagnosis, and at preresection and postresection. Patient and tumor characteristics, perioperative details, and oncologic outcomes were compared between minimally invasive surgery and open resection of tumors of comparable size. RESULTS: A total of 202 patients were treated for 206 intracavitary embryonal tumors, of which 178 were resected either open (n = 152, 85%) or with minimally invasive surgery (n = 26, 15%). The 5-year, relapse-free, and overall survival were not significantly different after minimally invasive surgery or open resection of tumors having a volume less than 100 mL, corresponding to the largest resected with minimally invasive surgery (P = .249 and P = .124, respectively). No difference in margin status or lymph node sampling between the 2 operative approaches was detected (p = .333 and p = .070, respectively). Advantages associated with minimally invasive surgery were decreased blood loss (P < .001), decreased operating time (P = .002), and shorter hospital stay (P < .001). Characteristically, minimally invasive surgery was used for smaller volume and earlier stage neuroblastic tumors without image-defined risk factors. CONCLUSION: When selected appropriately, minimally invasive resection of pediatric embryonal tumors, particularly neuroblastic tumors, provides acceptable oncologic integrity. Large tumor volume, small patient size, and image-defined risk factors may limit the broader applicability of minimally invasive surgery.

Molecular and epidemiologic characterization of Wilms tumor from Baghdad, Iraq.

BACKGROUND: Wilms tumor (WT) is the most common childhood kidney cancer worldwide, yet its incidence and clinical behavior vary according to race and access to adequate healthcare resources. To guide and streamline therapy in the war-torn and resource-constrained city of Baghdad, Iraq, we conducted a first-ever molecular analysis of 20 WT specimens to characterize the biological features of this lethal disease within this challenged population. METHODS: Next-generation sequencing of ten target genes associated with WT development and treatment resistance (WT1, CTNNB1, WTX, IGF2, CITED1, SIX2, p53, N-MYC, CRABP2, and TOP2A) was completed. Immunohistochemistry was performed for 6 marker proteins of WT (WT1, CTNNB1, NCAM, CITED1, SIX2, and p53). Patient outcomes were compiled. RESULTS: Mutations were detected in previously described WT "hot spots" (e.g., WT1 and CTNNB1) as well as novel loci that may be unique to the Iraqi population. Immunohistochemistry showed expression domains most typical of blastemal-predominant WT. Remarkably, despite the challenges facing families and care providers, only one child, with combined WT1 and CTNNB1 mutations, was confirmed dead from disease. Median clinical follow-up was 40.5 months (range 6-78 months). CONCLUSIONS: These data suggest that WT biology within a population of Iraqi children manifests features both similar to and unique from disease variants in other regions of the world. These observations will help to risk stratify WT patients living in this difficult environment to more or less intensive therapies and to focus treatment on cell-specific targets.