Minimally Invasive Surgery in Pediatric Surgical Oncology: Practice Evolution at a Contemporary Single-Center Institution and a Guideline Proposal for a Randomized Controlled Study.

Background: Despite the lack of randomized or controlled trials for minimally invasive surgery (MIS) in pediatric surgical oncology, the integration of MIS into the surgical practice of pediatric oncology has become increasingly popular. The aim of this study was to evaluate the implementation of MIS in a pediatric tertiary cancer center and compare present use of MIS to that in a previous analysis at our center. Methods: We retrospectively reviewed the medical records of patients with pediatric cancer treated with MIS at a single institution between 2000 and 2014. Results: A total of 252 MIS procedures were performed: 73 laparoscopic (29%) and 179 thoracoscopic (71%). MIS was used for diagnostic purposes in 59% (146 thoracoscopic and 34 laparoscopic) and the therapeutic resection in 24% (39 laparoscopic cases and 33 thoracoscopic cases). Conversion to an open procedure occurred in 18 tumor resections (6%) and in 22 diagnostic biopsies (7%), mostly due to technical challenges in identifying or mobilizing tumors. Complications occurred in seven tumor resections (2%) and included three pneumothoraces, two bleeding complications, one bowel injury, and one wound infection. Complications occurred in 10 diagnostic biopsies (3%), mostly pneumothoraces. No tumor upstaging or trocar site recurrences occurred (follow-up time, 1-15 years). Conclusions: Over the last decade, we demonstrate the evolution of MIS in the management of solid tumors in children. We encourage surgeons and oncologists to join the call to arms to establish prospective trials evaluating MIS in pediatric surgical oncology.

In-bag enzymatic splenic digestion: a novel alternative to manual morcellation?

BACKGROUND: Contained in-bag spleen morcellation is a conventional extraction technique for safe spleen removal during laparoscopic splenectomy. Existing data for the use of in-bag enzymatic splenic digestion as an alternative to morcellation are lacking. This proof-of-concept study sought to evaluate the effectiveness of single and combinatorial enzyme digestion of murine spleens. MATERIALS AND METHODS: Murine spleens were digested with collagenase alone or with combinations of commercially available enzymes (collagenase, elastase, hyaluronidase, neutral protease) to determine their degradation effect. The primary end point was the percentage of mass reduction at 15 and 30 min. RESULTS: For collagenase alone (n = 15), the mean reduction in mass was 14 ± 10% (range: 2%-31%) at 15 min and 30 ± 25% (range: 7%-100%) at 30 min. Using combinatorial dissolution with collagenase, hyaluronidase, and elastase (n = 8), the mean reduction in mass was 27 ± 16% (range: 6%-42%) at 15 min and 48 ± 27% (range: 3%-100%) at 30 min. Injecting the enzyme solution into whole spleens (n = 9) yielded a mean reduction in mass of 22 ± 13% (range: 9%-42%) at 15 min and 55 ± 31% (range: 9%-100%) at 30 min; mean reduction was 9 ± 13% (range: 0%-39%) at 15 min and 23 ± 13% (range: 3%-53%) with no injection (n = 12). CONCLUSIONS: We provide the first demonstration of successful enzymatic murine spleen digestion as an alternative method for in-bag spleen removal during laparoscopic splenectomy. However, the significant cost and quantities of commercial enzyme required for clinical application dampens the enthusiasm for this novel approach.

Operative and Immediate Postoperative Differences Between Traditional Multiport and Reduced Port Laparoscopic Total Splenectomy in Pediatric Patients.

BACKGROUND: Laparoscopy offers many benefits to splenectomy, such as reduced incisional pain and shortened hospital duration. The purpose of this study is to evaluate procedural and outcome differences between multiport (MP) and reduced port (RP) splenectomy when utilized to treat children. PATIENTS AND METHODS: An institutional review board approved retrospective analysis of all consecutive laparoscopic total splenectomies performed at a single institution between January 2010 and October 2015 was conducted. We evaluated demographics, surgical technique, instance of conversion, operative duration, estimated blood loss, need for intraoperative blood transfusion, postoperative length of stay, time to full feeds, complications, and follow-up duration. RESULTS: Over a 5-year period, 66 patients less than 20 years of age underwent laparoscopic total splenectomy. RP splenectomy was attempted in 14 patients. The remaining 52 were MP operations. Populations were comparable with regard to demographics. Preoperative splenic volumes (mL) were greater in the RP population (median [IQR]: 1377 [747-1508] versus 452 [242-710], P = .039). RP splenectomy demonstrated no difference compared to MP splenectomy in operative time (153 versus 138 minutes, P = .360), estimated blood loss (120 versus 154 mL, P = .634), or percent of cases requiring intraoperative blood transfusion (14 versus 23, P = .716). By the first postoperative day, 57% of RP and 17% of MP patients could be discharged (P = .005). Thirty-day readmission rates were similar, at 7% for RP and 8% for MP operations. Fever was the indication for all readmissions. Mean duration of follow-up is 28 months for MP and 13 months for RP cases. CONCLUSION: A reduced number of ports can be safely utilized for total splenectomy in pediatric patients without increasing procedural duration or need for intraoperative blood transfusion. In addition, rate of discharge on the first postoperative day was significantly higher in the RP splenectomy group.

Gastrostomy Complications in Pediatric Cancer Patients: A Retrospective Single-Institution Review.

BACKGROUND: Complications in pediatric cancer patients after a gastrostomy (GT) placement have not been widely investigated. We aimed to evaluate the complication rate and nature of complications in this specific population. PROCEDURE: Medical records of pediatric cancer patients having a GT placed at our institution from 1998 to 2013 were retrospectively reviewed. Variables analyzed included gender, age, diagnosis, surgical procedure, GT device, duration of GT usage, absolute neutrophil count (ANC) level at surgery, and complications. RESULTS: One hundred seventy-one patients (92 males, 79 females), median age of 6 years (range, 0.2-21), who underwent 181 procedures (110 open, 59 endoscopic, and 12 laparoscopic) were identified. Diagnosis included central nervous system tumor (n = 101), solid tumor (n = 45), and leukemia/lymphoma (n = 25). A GT tube was used in 139 procedures and a GT button in 42. Median ANC level at procedure was 3,300/mm(3) (range, 0-38,988). Median duration of GT usage was 8 months (range, 0.2-142). One hundred seventy-seven complications occurred in 106 patients (61.9%) and were categorized as perioperative (<1 month after surgery, 20.3%) and late (>1 month after surgery, 79.7%). Major complications included 42 (23.7%) GT site infections and four (2.2%) intrabdominal complications. The most common minor complication was granulation tissue (28.8%). Younger age at procedure was associated with complications (P = 0.048) and an open technique was associated with GT site infection (P = 0.003). No statistical significance was observed between complications and gender, diagnosis, GT device, duration of GT usage, and ANC at procedure. CONCLUSIONS: Younger patients were more likely to have complications, and GT site infections were more common after open GT procedures.

Risk-reduction surgery in pediatric surgical oncology: A perspective.

OBJECTIVE: A small percentage of pediatric solid cancers arise as a result of clearly identified inherited predisposition syndromes and nongenetic lesions. Evidence supports preemptive surgery for children with genetic [multiple endocrine neoplasia type 2 (MEN2), familial adenomatous polyposis syndrome (FAP), hereditary nonpolyposis colorectal cancer (HNPCC), and hereditary diffuse gastric cancer (HDGC) and nongenetic [thyroglossal duct cysts (TGDC), congenital pulmonary airway malformations (CPAM), alimentary tract duplication cysts (ATDC), and congenital choledochal cysts (CCC)] developmental anomalies. Our aim was to explore the utility of risk reduction surgery to treat and prevent cancer in children. METHODS: A systematic review of the available peer-reviewed literature on PubMed was performed using a PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) search strategy, where possible. Search items included "risk reduction surgery", "hereditary cancer predisposition syndrome", "multiple endocrine neoplasia type 2", "familial adenomatous polyposis", "hereditary nonpolyposis colorectal cancer", "hereditary diffuse gastric cancer", "thyroglossal duct cysts", congenital pulmonary airway malformations", "alimentary tract duplication cysts", "malignant transformation", and "guidelines". RESULTS: We identified 67 articles that met the inclusion criteria describing the indications for prophylactic surgery in surgical oncology. For the genetic predisposition syndromes, 7 studies were related to professional endorsed guidelines, 7 were related to surgery for MEN2, 11 were related to colectomy for FAP, 6 were related to colectomy for HNPCC, and 12 related to gastrectomy for HDGC. Articles for the nongenetic lesions included 5 for techniques related to TGDC resection, 9 for surgery for CPAMs, and 10 for resection of ATDCs. Guidelines and strategies varied significantly especially related to the extent and timing of surgical intervention; the exception was for the timing of thyroidectomy in children with MEN2. CONCLUSION: Current evidence supporting prophylactic surgery in the management of pediatric cancer predisposition syndromes and nongenetic lesions is best delineated for thyroidectomy to prevent medullary thyroid cancer in children with MEN2 (Strength of Recommendation Grade B/C). Despite the lack of pediatric specific evidence-based recommendations regarding the appropriate extent and timing for risk-reduction surgery for FAP, HNPCC, HDGC and nongenetic anomalies, our review represents an opportunity towards understanding the postgenomic development of these lesions and provides current indications and techniques for preemptive cancer prevention surgery in children.

Reconstruction of Desmoid Tumors: Case Series and Systematic Review.

BACKGROUND: Desmoid tumors (DT) represent a group of rare, distinct lesions. There are few published studies examining outcomes and safety of complex reconstruction after DT resection. METHODS: A retrospective review identified 39 patients who underwent surgical treatment of DT at St. Jude Children's Research Hospital over a 12-year period. A systematic review of the literature identified 17 further studies for inclusion. Treatment characteristics were analyzed. RESULT: Thirty-nine patients were treated during the study period, with a total number of 67 resections. Median age was 12.2 years; 49% of patients were male, and 51% were female. Median tumor size was 9.8 cm. DT most commonly arose in the extremities (40%), thorax (23%), head and neck (21%), and trunk (16%). One- and 5-year recurrence-free survival were 97.1% and 73.1%, respectively. The majority of defects were closed primarily, with the exception of head and neck defects. Long-term outcomes were good for chest, abdomen, and upper extremity defects, but were problematic for head and neck, breast, and lower extremity defects. There were no recurrences at the site of flap harvest in either the study population or in reviewed studies. CONCLUSION: For patients with DT, surgical extirpation should not come at the expense of functional preservation, as overall survival is excellent. However, specific defects, including those of the lower extremity, breast, and head and neck, will benefit from improved techniques for resection and reconstruction.

Hepatic metastatic disease in pediatric and adolescent solid tumors.

The management of hepatic metastatic disease from solid tumors in adults has been extensively described and resection of metastatic liver lesions from colorectal adenocarcinoma, renal adenocarcinoma, breast cancer, testicular cancer, and neuroendocrine tumors (NET) have demonstrated therapeutic benefits in select patients. However, there are few reports in the literature on the management of hepatic metastatic disease in the pediatric and adolescent populations and the effectiveness of hepatic metastasectomy. This may be due to the much lower incidence of pediatric malignancies and the higher chemosensitivity of childhood tumors which make hepatic metastasectomy less likely to be required. We review liver involvement with metastatic disease from the main pediatric solid tumors, including neuroblastoma and Wilms tumor focusing on the management and treatment options. We also review other solid malignant tumors which may have liver metastases including germ cell tumors, gastrointestinal stromal tumors, osteosarcoma, desmoplastic small round cell tumors and NET. However, these histological subtypes are so rare in the pediatric and adolescent populations that the exact incidence and best management of hepatic metastatic disease are unknown and can only be extrapolated from adult series.

Neonatal Germ Cell Tumors.

Excluding hemangiomas, germ cell tumors (GCTs) are the most common neoplasm in neonates, comprising a wide range of benign and malignant tumors with unique histological diversity. Although these tumors are relatively rare, antenatal ultrasonography has increased their detection before birth. Extragonadal GCTs (EGCTs) are the most common GCTs in neonates, with sacrococcygeal teratomas (SCTs) being the most prevalent EGCTs. SCTs are characterized as protruding masses arising from the sacrococcygeal region with or without variable extension into the presacral space. Patients with SCTs typically have an excellent prognosis, though this is dependent on the ease of surgical resection, the timing of diagnosis, and the malignant potential of the tumor. Whereas some GCTs can be diagnosed and treated prenatally, this review focuses on postnatal management of GCTs. We explore the embryological development, histopathology, biomarkers, clinical presentation, diagnostic features, and treatment of neonatal GCTs. Because the overall prognosis is excellent for the majority of patients with GCTs, we also discuss the potential long-term effects of antineoplastic agents used to treat patients with malignant disease.

An approach to renal masses in pediatrics.

Renal masses in children may be discovered during routine clinical examination or incidentally during the course of diagnostic or therapeutic procedures for other causes. Renal cancers are rare in the pediatric population and include a spectrum of pathologies that may challenge the clinician in choosing the optimal treatment. Correct identification of the lesion may be difficult, and the appropriate surgical procedure is paramount for lesions suspected to be malignant. The purpose of this article is to provide a comprehensive overview regarding the spectrum of renal tumors in the pediatric population, both benign and malignant, and their surgical management.

The Mechanism by Which MYCN Amplification Confers an Enhanced Sensitivity to a PCNA-Derived Cell Permeable Peptide in Neuroblastoma Cells.

Dysregulated expression of MYC family genes is a hallmark of many malignancies. Unfortunately, these proteins are not amenable to blockade by small molecules or protein-based therapeutic agents. Therefore, we must find alternative approaches to target MYC-driven cancers. Amplification of MYCN, a MYC family member, predicts high-risk neuroblastoma (NB) disease. We have shown that R9-caPep blocks the interaction of PCNA with its binding partners and selectively kills human NB cells, especially those with MYCN amplification, and we now show the mechanism. We found elevated levels of DNA replication stress in MYCN-amplified NB cells. R9-caPep exacerbated DNA replication stress in MYCN-amplified NB cells and NB cells with an augmented level of MYC by interfering with DNA replication fork extension, leading to Chk1 dependence and susceptibility to Chk1 inhibition. We describe how these effects may be exploited for treating NB.

The role of thoracoscopic surgery in pediatric oncology.

The application of thoracoscopic surgical techniques to pediatric solid tumors represents an important adjunctive tool for the surgical management of childhood cancer. Nearly four decades has passed since the introduction of minimally invasive chest surgery in children, and although the adoption of minimally invasive surgery in general pediatric surgical practice is better recognized, its role in pediatric oncology is still considered a developing field. As no consensus exists regarding the use of thoracoscopy for pediatric thoracic solid tumors, the purpose of this article is to review the current literature surrounding the use of thoracoscopic interventions in pediatric oncology and examine established indications, procedures, and technologic advances.

Aggressive Cunninghamella pneumonia in an adolescent.

Children with hematologic malignancies may be challenged with life-threatening, invasive fungal infections by organisms that would otherwise have a low potential for virulence in healthy hosts. Presented is a case of a 15-year-old adolescent with B-cell acute lymphoblastic leukemia who was receiving steroids and chemotherapy. He developed cough associated with left chest pain with suspicion for fungal pneumonia. He began systemic antifungal therapy, underwent computed tomography of the chest demonstrating a large cavitary lesion (reversed halo sign) in the left lung. Over a 48-hour period the patient clinically deteriorated with worsening pneumonia and required left thoracotomy with nonanatomic pulmonary resection. This case illustrates the aggressive nature of Cunninghamella pneumonia in patients with hematologic malignancies, and the multidisciplinary approach required to have the greatest possible outcome.

Detection of PI3K inhibition in human neuroblastoma using multiplex luminex bead immunoassay: a targeted approach for pathway analysis.

Neuroblastoma (NB) is a common solid tumor in children. Outcomes for advanced stage NB have not improved, at least in part because of multimodality therapy resistance. Better comprehension of novel molecular targets will likely lead to improved therapies with specific cytotoxic agents. For instance, the role of deregulated IGF-1R/AKT/PI3K/mTOR (PI3K) pathway activity has attracted much attention across several tumors, including NB. Thus, modulating this pathway via anti-PI3K drugs has taken center stage in many cancer clinical trials. However, varied clinical effects have hampered the precise application of these agents. Tumor PI3K pathway profiling may reveal a method to enhance the efficacy of these inhibitors. To this end, solid-phase antibody-based array platforms have emerged as a direct, rapid means of profiling intracellular signaling pathways. We tested the efficacy of four PI3K inhibitors against a panel of human NB cell lines using Luminex xMAP bead array technology to establish PI3K phosphoprotein profiles. We demonstrate the utility of the xMAP approach in following intracellular signaling signatures specific for PI3K targeted therapy. Further validation is required before xMAP is used routinely for clinical PI3K pathway evaluation, but this method may eventually be personalized by taking into account each child's basal NB pathway status.

Minimally invasive surgery in the management of abdominal tumors in children.

The application of minimally invasive surgical techniques to pediatric abdominal tumors is a controversial application towards the surgical management of childhood cancer. Although general pediatric surgeons practice minimally invasive surgery techniques in a vast array of abdominal cases, its role in pediatric oncology is still developing, with no consensus in North America about its use for pediatric solid abdominal tumors. The purposes of this article are to review the current literature about the use of minimally invasive surgery in pediatric abdominal oncology and to examine established indications, procedures and technologic advances.

A PCNA-derived cell permeable peptide selectively inhibits neuroblastoma cell growth.

Proliferating cell nuclear antigen (PCNA), through its interaction with various proteins involved in DNA synthesis, cell cycle regulation, and DNA repair, plays a central role in maintaining genome stability. We previously reported a novel cancer associated PCNA isoform (dubbed caPCNA), which was significantly expressed in a broad range of cancer cells and tumor tissues, but not in non-malignant cells. We found that the caPCNA-specific antigenic site lies between L126 and Y133, a region within the interconnector domain of PCNA that is known to be a major binding site for many of PCNA's interacting proteins. We hypothesized that therapeutic agents targeting protein-protein interactions mediated through this region may confer differential toxicity to normal and malignant cells. To test this hypothesis, we designed a cell permeable peptide containing the PCNA L126-Y133 sequence. Here, we report that this peptide selectively kills human neuroblastoma cells, especially those with MYCN gene amplification, with much less toxicity to non-malignant human cells. Mechanistically, the peptide is able to block PCNA interactions in cancer cells. It interferes with DNA synthesis and homologous recombination-mediated double-stranded DNA break repair, resulting in S-phase arrest, accumulation of DNA damage, and enhanced sensitivity to cisplatin. These results demonstrate conceptually the utility of this peptide for treating neuroblastomas, particularly, the unfavorable MYCN-amplified tumors.

Targeting oxidative stress in embryonal rhabdomyosarcoma.

Rhabdomyosarcoma is a soft-tissue sarcoma with molecular and cellular features of developing skeletal muscle. Rhabdomyosarcoma has two major histologic subtypes, embryonal and alveolar, each with distinct clinical, molecular, and genetic features. Genomic analysis shows that embryonal tumors have more structural and copy number variations than alveolar tumors. Mutations in the RAS/NF1 pathway are significantly associated with intermediate- and high-risk embryonal rhabdomyosarcomas (ERMS). In contrast, alveolar rhabdomyosarcomas (ARMS) have fewer genetic lesions overall and no known recurrently mutated cancer consensus genes. To identify therapeutics for ERMS, we developed and characterized orthotopic xenografts of tumors that were sequenced in our study. High-throughput screening of primary cultures derived from those xenografts identified oxidative stress as a pathway of therapeutic relevance for ERMS.

Surgical treatment of pediatric desmoid tumors. A 12-year, single-center experience.

BACKGROUND: Pediatric desmoid tumors (PDTs) represent a group of rare, distinct lesions. While sparse, available literature suggests that PDT are particularly aggressive and difficult to control when compared with their adult counterpart. METHODS: A retrospective review identified 39 patients who underwent treatment of PDT at St. Jude Children's Research Hospital over a 12-year period. Clinicopathologic and treatment characteristics were analyzed to identify predictors of outcome. RESULT: A total of 39 patients were treated during the study period, with a total number of 67 resections. Median age was 12.2 years; 49 % of patients were male, and 51 % were female. Median tumor size was 9.8 cm. PDT most commonly arose in the extremities (40 %), thorax (23 %), head and neck (21 %), and trunk (16 %). Also, 18 % of resections had negative margins (R0), 48 % were microscopic positive (R1), and 30 % were macroscopic positive (R2). The 1- and 5-year recurrence-free survival (RFS) was 97.1 and 73.1 %, respectively. Factors associated with worse RFS were patient age >12 years (HR = 5.08, p = 0.038) and tumor size >5 cm (HR = 1.22, p = 0.0597). Margin status did not affect RFS. Selective use of radiation therapy appeared to improve RFS. CONCLUSIONS: Our study suggests that margin status alone at the time of extirpation is not a predictor of ultimate cure or likelihood of recurrence. Many patients received adjuvant therapy, with benefits suggested after analysis. For patients with PDT, surgical extirpation should not come at the expense of functional preservation, as overall survival is excellent.

Dissecting the PI3K Signaling Axis in Pediatric Solid Tumors: Novel Targets for Clinical Integration.

Children with solid tumors represent a unique population. Recent improvements in pediatric solid tumor survival rates have been confined to low- and moderate-risk cancers, whereas minimal to no notable improvement in survival have been observed in high-risk and advanced-stage childhood tumors. Treatments for patients with advanced disease are rarely curative, and responses to therapy are often followed by relapse, which highlights the large unmet need for novel therapies. Recent advances in cancer treatment have focused on personalized therapy, whereby patients are treated with agents that best target the molecular drivers of their disease. Thus, a better understanding of the pathways that drive cancer or drug resistance is of critical importance. One such example is the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway, which is activated in many solid cancer patients and represents a target for therapy. PI3K/Akt/mTOR pathway activation has also been observed in tumors resistant to agents targeting upstream receptor tyrosine kinases (RTKs). Agents that target this pathway have the potential to shut down survival pathways, and are being explored both in the setting of pathway-activating mutations and for their ability to restore sensitivity to upstream signaling targeted agents. Here, we examine the role of the PI3K/Akt/mTOR pathway in pediatric solid tumors, review the novel agents being explored to target this pathway, and explore the potential role of the inhibition of this pathway in the clinical development of these agents in children.