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No previous research papers have reported a comparative survey of local radiologic diagnoses and central review in children with hepatoblastoma.To evaluate the utility of central review of children with hepatoblastoma enrolled in a clinical trial.The study included 91 children enrolled in a clinical trial conducted by the Japanese Study Group for Pediatric Liver Tumor. We compared the results of the initial pre-treatment extent of tumor (PRETEXT) disease staging performed at local sites with the results obtained on central review to determine the concurrence rates for tumor staging and additional criteria.The concurrence rate for PRETEXT staging was 70%. As the stage increased, the concurrence rate decreased. Using additional criteria, central review identified 143 lesions (157.1%), about 1.8 times higher than the number identified for the local site diagnoses. The additional criterion found most often on central review was "multifocal lesion" (n=19). The concurrence rate for lung metastases was high. However, our central review found many false-positive assertions of hepatic vein lesions, portal vein invasion and extrahepatic lesions among the local site diagnoses.In a clinical trial of hepatoblastoma, central review provided a more precise diagnosis than local site diagnoses with respect to severe PRETEXT stages III and IV cases and other cases including hepatic and portal vein invasion. The central review process appears to be effective and essential for improving the quality of clinical trials.

In the present study, we found that EZH1 depletion in MYCN-amplified neuroblastoma cells resulted in significant cell death as well as xenograft inhibition. EZH1 depletion decreased the level of H3K27me1; the interaction and protein stabilization of MYCN and EZH1 appear to play roles in epigenetic transcriptional regulation. Transcriptome analysis of EZH1-depleted cells resulted in downregulation of the cell cycle progression-related pathway. In particular, Gene Set Enrichment Analysis revealed downregulation of reactome E2F-mediated regulation of DNA replication along with key genes of this process, TYMS, POLA2, and CCNA1. TYMS and POLA2 were transcriptionally activated by MYCN and EZH1-related epigenetic modification. Treatment with the EZH1/2 inhibitor UNC1999 also induced cell death, decreased H3K27 methylation, and reduced the levels of TYMS in neuroblastoma cells. Previous reports indicated neuroblastoma cells are resistant to 5-fluorouracil (5-FU) and TYMS (encoding thymidylate synthetase) has been considered the primary site of action for folate analogues. Intriguingly, UNC1999 treatment significantly sensitized MYCN-amplified neuroblastoma cells to 5-FU treatment, suggesting that EZH inhibition could be an effective strategy for development of a new epigenetic treatment for neuroblastoma.

Purpose Hepatobiliary scintigraphy is a minimally invasive imaging method that evaluates bile flow dynamics. At our hospital, it has been performed for postoperative evaluation of patients with choledochal cysts (CC). This study evaluated the usefulness of biliary scintigraphy for predicting late complications in patients with CCs. Methods The study included pediatric patients with CC who underwent surgery at Chiba University Hospital from 1978 to 2020, followed by postoperative biliary scintigraphy and subsequent radiologic evaluation. The patients were divided into two groups according to the presence or absence of “biliary cholestasis” on biliary scintigraphy. Results The study included 108 patients, with a median age at surgery of 2 years and 11 months. The median follow-up period was 5203 days, with 11 hepatolithiasis cases and 8 cholangitis cases. No patients had cholangiocarcinoma. Twelve patients were considered to have “cholestasis” following biliary scintigraphy evaluation. There was no significant difference in the occurrence of hepatolithiasis between the cholestasis and non-cholestasis groups (p = 0.47), but cholangitis was significantly more common in the cholestasis group (p = 0.016). Conclusion Biliary cholestasis on postoperative hepatobiliary scintigraphy was a risk factor for cholangitis in patients with CCs. These particular patients should be monitored carefully.

Hepatoblastoma (HB) is the most common paediatric liver tumour, and epigenetic aberrations may be important in HB development. Recently, the Children's Hepatic Tumors International Collaboration-Hepatoblastoma Stratification (CHIC-HS) developed risk stratification based on clinicopathological factors. This study aimed to construct a more accurate model by integrating CHIC-HS with molecular factors based on DNA methylation.HB tumour specimens (N = 132) from patients treated with the Japanese Pediatric Liver Tumors Group-2 protocol were collected and subjected to methylation analysis by bisulfite pyrosequencing. Associations between methylation status and clinicopathological factors, overall survival (OS), and event-free survival (EFS) were retrospectively analysed. We investigated the effectiveness of the evaluation of methylation status in each CHIC-HS risk group and generated a new risk stratification model.Most specimens (82%) were from post-chemotherapy tissue. Hypermethylation in ≥2 of the four genes (RASSF1A, PARP6, OCIAD2, and MST1R) was significantly associated with poorer OS and EFS. Multivariate analysis indicated that ≥2 methylated genes was an independent prognostic factor (hazard ratios of 6.014 and 3.684 for OS and EFS, respectively). Two or more methylated genes was also associated with poorer OS in the CHIC-very low (VL)-/low (L)-risk and CHIC-intermediate (I) risk groups (3-year OS rates were 83% vs. 98% and 50% vs. 95%, respectively). The 3-year OS rates of the VL/L, I, and high-risk groups in the new stratification model were 98%, 90%, and 62% (vs. CHIC-HS [96%, 82%, and 65%, respectively]), optimising CHIC-HS.Our proposed stratification system considers individual risk in HB and may improve patient clinical management.

Liquid biopsy, a method of detecting genomic alterations using blood specimens, has recently attracted attention as a noninvasive alternative to surgical tissue biopsy. We attempted quantitative analysis to detect amplification of MYCN (MYCNamp) and loss of heterozygosity at 11q (11qLOH), which are clinical requisites as prognostic factors of neuroblastoma (NB). In this study, cell-free DNA (cfDNA) was extracted from plasma samples from 24 NB patients at diagnosis. Copy numbers of MYCN and NAGK genes were quantitatively analyzed by droplet digital PCR (ddPCR). 11qLOH was also assessed by detecting allelic imbalances of heterozygous single nucleotide polymorphisms in the 11q region. The results obtained were compared to those of specimens from tumor tissues. The correlation coefficient of MYCN copy number of cfDNA and tumor DNA was 0.88 (p 0.00001). 11qLOH was also accurately detected from cfDNA, except for one case with localized NB. Given the high accuracy of liquid biopsy, to investigate components of cfDNA, the proportion of tumor-derived DNA was estimated by examining the variant allele frequency of tumor-specific mutations in cfDNA. The proportion of tumor-derived DNA in cfDNA was 42.5% (range, 16.9%-55.9%), suggesting sufficient sensitivity of liquid biopsy for NB. In conclusion, MYCN copy number and 11qLOH could be quantitatively analyzed in plasma cfDNA by ddPCR assay. These results suggest that plasma cfDNA can be substituted for tumor DNA and can also be applied for comprehensive genomic profiling analysis.

Background Clinical trials have reported the efficacy of tropomyosin receptor kinase (TRK) inhibitors against neurotrophic receptor tyrosine kinase (NTRK) fusion gene-positive advanced solid tumors. The accumulated evidence of tumor-agnostic agent has made since TRK inhibitors were approved and used in clinical practice. Therefore, we have revised the ‘Japan Society of Clinical Oncology (JSCO)/Japanese Society of Medical Oncology (JSMO)-led clinical recommendations on the diagnosis and use of tropomyosin receptor kinase inhibitors in adult and pediatric patients with neurotrophic receptor tyrosine kinase fusion-positive advanced solid tumors, cooperated by the Japanese Society of Pediatric Hematology/Oncology (JSPHO)’. Methods Clinical questions regarding medical care were formulated for patients with NTRK fusion-positive advanced solid tumors. Relevant publications were searched by PubMed and Cochrane Database. Critical publications and conference reports were added manually. Systematic reviews were performed for each clinical question for the purpose of developing clinical recommendations. The committee members identified by JSCO, JSMO, and JSPHO voted to determine the level of each recommendation considering the strength of evidence, expected risks and benefits to patients, and other related factors. Thereafter, a peer review by experts nominated from JSCO, JSMO, and JSPHO, and the public comments among all societies' members was done. Results The current guideline describes 3 clinical questions and 14 recommendations for whom, when, and how NTRK fusion should be tested, and what is recommended for patients with NTRK fusion-positive advanced solid tumors. Conclusion The committee proposed 14 recommendations for performing NTRK testing properly to select patients who are likely to benefit from TRK inhibitors.

Small cell undifferentiated (SCU) histology and alpha-fetoprotein (AFP) levels below 100 ng/mL have been reported as poor prognostic factors in hepatoblastoma (HB); subsequent studies reported SMARCB1 mutations in some SCU HBs confirming the diagnosis of rhabdoid tumor. The Children’s Hepatic tumors International Collaboration (CHIC) database was queried for patients with HB who had AFP levels less than 100 ng/mL at diagnosis or were historically diagnosed as SCU HBs. Seventy-three of 1605 patients in the CHIC database were originally identified as SCU HB, HB with SCU component, or HB with low AFP levels. Upon retrospective review, they were re-classified as rhabdoid tumors (n = 11), HB with SCU component (n = 41), and HB with low AFP (n = 14). Seven were excluded for erroneously low AFP levels. Overall survival was 0% for patients with rhabdoid tumors, 76% for patients with HB with SCU component, and 64% for patients with HB with AFP less than 100 ng/mL. Patients with HB with SCU component or low AFP should be assessed for SMARCB1 mutations and, if confirmed, treated as rhabdoid tumors. When rhabdoid tumors are excluded, the presence of SCU component and low AFP at diagnosis were not associated with poor prognosis in patients diagnosed with HB.

Purpose Although the impairment of regulatory T-cells (Tregs) has been shown in the liver or portal area of biliary atresia (BA) the frequency and function of circulating Tregs in BA patients is poorly understood. We aimed to investigate the frequency and function of circulating Tregs in BA patients. Methods Peripheral blood mononuclear cells were collected from 25 BA patients and 24 controls. Treg frequency was measured by flow cytometry; function was determined by T-cell proliferation assay. We also assessed the association between Treg frequency/function and clinical parameters in BA cases. Results There was no significant difference between the two groups in both frequency (BA: 3.4%; control: 3.2%; p = 0.97) and function (BA: 22.0%; control: 7.5%; p = 0.23) of Tregs. We further focused on 13 preoperative BA patients and 14 age-matched controls. Neither Treg frequency nor function were significantly different (frequency: BA: 4.6%; control: 3.4%; p = 0.38, function: BA: 2.7%; control: 7.6%; p = 0.89). There was no association between Treg frequency/function and clinical parameters. Conclusion Neither the frequency nor function of circulating Tregs was affected in BA patients, suggesting the negative role of circulating Tregs in the pathogenesis of BA. Further investigation of local Treg profiles is warranted.

Minimally invasive surgery (MIS) is appropriate for the treatment of some neuroblastomas (NBs); however, the indications and technical issues are unclear. This study aimed to clarify the current status of MIS for mediastinal NB in Japan. Preliminary questionnaires requesting the numbers of neuroblastoma cases in which MIS was performed from 2004 to 2016 were sent to 159 Japanese institutes of pediatric surgery. Secondary questionnaires were sent to institutions with MIS cases to collect detailed data. One hundred thirty-four (84.2%) institutions returned the preliminary questionnaire and 83 institutions (52.2%) reported a total of 1496 operative cases. MIS was performed for 175 (11.6%) cases. Among the 175 cases, completed forms of 140 patients were returned and 40 (male, n = 28; female, n = 12) cases had mediastinal NB. Fourteen patients received thoracoscopic biopsy, none were converted to thoracotomy. Twenty-eight patients received MIS for radical resection, none were converted to thoracotomy. Perioperative complications (Horner’s syndrome) were recognized after radical resection in one (2.5%) case. MIS was performed in a limited number of mediastinal NB cases. A thoracoscopic approach would be feasible for mediastinal NB.

Some neuroblastoma (NB) cases are suitable for minimally invasive surgery (MIS), but indication and technical issue are unclear. We assessed the current status of MIS for abdominal NB after mass screening period in Japan. Preliminary questionnaires requesting the numbers of NB cases that underwent MIS from 2004 to 2016 were sent to 159 Japanese institutes of pediatric surgery. The secondary questionnaires were then sent to the institutions that reported MIS cases of NB in order to collect detailed data. One hundred and thirty-four (84.2%) institutions responded to the preliminary questionnaires, and 83 (52.2%) reported managing operative cases. The total number of operative cases was 1496. MIS was performed for 175 (11.6%) cases, of which the completed forms of 140 patients were returned, including 100 abdominal NB cases. The male/female ratio was 51/49. Forty-seven cases underwent a laparoscopic biopsy, and 2 (4.3%) cases were converted to laparotomy due to bleeding. Sixty-five cases underwent MIS for radical resection, and 7 (10.8%) were converted to laparotomy. The reasons for open conversion were bleeding and severe adhesion. Regarding open conversion, there were no significant relationships between conversion and neo-adjuvant chemotherapy, biopsies, stage, size, or MYCN amplification. We found no relationship between resectability and vascular encasement in this study. There was relationship between the resected tumor size and the patients’ height, which was expressed using the following formula: $$y = 0.0316x + 1.4812$$ (x, patients height, y, tumor size; p = 0.004219, SE: 1.55566). Postoperative complications after radical resection were recognized in 7 (10.8%) cases. MIS was performed in limited cases of abdominal NB. A laparoscopic biopsy with careful attention to bleeding is feasible. The resected tumor size was shown to correlate with the patients’ height. Tumor size within 6 cm of maximum diameter can be resected safely.

Two cases of pediatric lung cancer (in 23-month-old and 6-year-old boys) resulting from mother-to-infant transmission of uterine cervical tumors were incidentally detected during routine next-generation sequencing of paired samples of tumor and normal tissue. Spontaneous regression of some lesions in the first child and slow growth of the tumor mass in the second child suggested the existence of alloimmune responses against the transmitted tumors. Immune checkpoint inhibitor therapy with nivolumab led to a strong regression of all remaining tumors in the first child. (Funded by the Japan Agency for Medical Research and Development and others; TOP-GEAR UMIN Clinical Trials Registry number, UMIN000011141.).

Purpose The optimal timing of surgery for congenital diaphragmatic hernia (CDH) is controversial. We aimed to validate our protocol for the timing of CDH repair using the quantified patent ductus arteriosus (PDA) flow pattern. Methods This retrospective comparative study analyzed patients with a prenatal diagnosis of isolated CDH between 2007 and 2020. We defined the “LR ratio” as the percentage of velocity–time integral (VTI) of the left-to-right flow of PDA against overall VTI on echocardiography. Since 2010, we followed the decision criterion of performing surgery when LR ratio of > 50% has been achieved in the patients (protocol group). The protocol group (2010–2020) was compared with the historical control group (2007–2009). Results The average age at surgery was 104.1 ± 175.9 and 37.3 ± 30.6 h in the control and protocol groups, respectively (p = 0.11). Survival rate (88.9% vs. 95.0%, p = 0.53) and the rate of worsening of pulmonary hypertension within 24 h after surgery (22.2% vs. 10.0%, p = 0.57) were not different between the groups. The protocol group had a significantly shorter duration of tracheal intubation (26.9 ± 21.1 vs. 13.3 ± 9.5 days, p = 0.03). Conclusion Our decision criterion might have the advantage of facilitating early and safe surgery for patients with CDH.

The delayed local treatment approach (DL) in high-risk neuroblastoma (HR-NB) refers to the process in which tumor resection is performed after the completion of all the courses of chemotherapy, including myeloablative high-dose chemotherapy (HDC). Alternatively, in the conventional local treatment approach (CL), tumor resection is performed during induction chemotherapy. In this study, we compared the surgical outcomes in HR-NB patients treated by CL and DL.Forty-seven patients with abdominal HR-NB underwent primary tumor resection from 2002 to 2018. The timing of surgery was generally determined by following the trials and guidelines available at the time. The outcomes and surgical complications between the two strategies were compared.Operation time, blood loss, and postoperative WBC counts were lower in the DL group (n = 25) when compared to the CL group (n = 22), statistical significance notwithstanding. Major vascular structures were less frequently encased in the DL group tumors, while immediate surgical complications were significantly more frequent in the CL group (P 0.05). Furthermore, the 3-year EFSs were 50.0% and 53.9% in the DL and CL groups, respectively.DL appears to be a feasible and effective treatment option for HR-NB. Nonetheless, further verifications using larger cohorts are warranted.Treatment study, Level III.

Purpose Oncolytic viral therapy for neuroblastoma (NB) cells with Sindbis virus (SINV) is a promising strategy for treating high-risk NB. Here, we evaluated the possibility of using SINV structural proteins as therapeutic agents for NB since UV-inactivated SINV could induce cytopathogenic effects. Methods The cytotoxicity of UV-inactivated SINV toward human NB cell lines NB69, NGP, GOTO, NLF, SK-N-SH, SH-SY5Y, CHP134, NB-1, IMR32, and RT-BM-1 were analyzed. Apoptosis was confirmed by TUNEL assays. To determine the components of SINV responsible for the cytotoxicity of UV-inactivated SINV, expression vectors encoding the structural proteins, namely capsid, E2, and E1, were transfected in NB cells. Cytotoxicity was evaluated by MTT assays. Results UV-inactivated SINV elicited more significant cytotoxicity in NB69, NGP, and RT-BM-1 than in normal human fibroblasts. Results of the transfection experiments showed that all NB cell lines susceptible to UV-inactivated SINV were highly susceptible to the E1 protein, whereas fibroblasts transfected with vectors harboring capsid, E1, or E2 were not. Conclusions We demonstrated that the cytotoxicity of the UV-inactivated SINV is due to apoptosis induced by the E1 structural protein of SINV, which can be used selectively as a therapeutic agent for NB.

Rationale: Unresectable abdominal tumors cause various complications, and fistulizaton with intestine is a rare but serious complication. We report this condition in 2 cases. Patient Concerns: The first case was that of a 14-year-old male patient who had a desmoid tumor and the second case was that of a 17-year-old female patient with a recurrent malignant peripheral nerve sheath tumor. They were admitted with a giant chemoresistant tumor that was gradually growing and causing abdominal pain. Diagnoses: They were diagnosed with intertumor abscesses caused by fistulous communications with the intestine. Interventions: Both the patients underwent percutaneous drainage, and after being stabilized, they underwent surgery. Outcomes: The patient with desmoid tumor was continuing his daily routine without any problem. The patient with malignant peripheral nerve sheath tumor was able to consume food orally and discharged after the surgery. Lessons: In the treatment of abdominal intratumor abscesses caused by fistulous communications with intestine, it is necessary to consider the optimal treatment strategies based on the tumor location and patient prognosis.

Anorectal malformations are associated with other organ malformations. Proximodistal elongation of the cloacal plate and anal opening at its distal end are essential for anal development. However, the anal developmental stage in which Wnt5a is directly involved remains unelucidated. Here, we attempted to identify this developmental stage; since Wnt5a is expressed in the mesoderm, and the striated muscle complex (SMC) in mice develops from the mesoderm, we also examined Wnt5a contribution to SMC development.We established conditional knockout (CKO) mice in which Wnt5a could be knocked out using an appropriate tamoxifen dose. We evaluated the macroscopic appearance and histopathological features of Wnt5aCKO and wild-type mouse embryos.Wnt5aCKO mice showed phenotypes typical of Wnt5a constitutional knockout mice when Wnt5a was knocked out at E8-E11. Furthermore, the anus failed to open when Wnt5a was knocked out at E8 but opened when it was knocked out at E9 or thereafter. The caudal end of the SMC was dysplastic in Wnt5aCKO mice induced at E8, but was unaffected when mice were induced at E9 or thereafter.We suggest a critical role for Wnt5a in anal opening and SMC formation at a very early stage of embryonic development.

Background The SIOPEL-4 study has demonstrated that dose-dense cisplatin-based chemotherapy dramatically improves outcome in children with high-risk hepatoblastoma in western countries. However, the feasibility and safety of this regimen have not been clarified in Japanese patients. Methods A pilot study, JPLT3-H, was designed to evaluate the safety profile of the SIOPEL-4 regimen in Japanese children with newly diagnosed hepatoblastoma with either metastatic disease or low alpha-fetoprotein. Results A total of 15 patients (three female) were enrolled. Median age was 2 years (range, 0-14). Three patients were PRETEXT II (where PRETEXT is PRETreatment EXTent of disease), six PRETEXT III, and six PRETEXT IV. All patients had lung metastasis, none had low alpha-fetoprotein. Eight patients completed the prescribed treatment, and seven patients discontinued therapy prematurely, four due to progressive disease and three due to causes other than severe toxicity. Grade 4 neutropenia was documented in most patients in preoperative cycles A1-3 (11/15 in A1, 9/11 in A2, and 7/11 in A3) and in all considering all cycles. Grade 3-4 thrombocytopenia and grade 3 anemia were also frequently observed. Patients experienced several episodes of grade 3 febrile neutropenia, but none had grade 4 febrile neutropenia or severe infections. One patient had grade 3 heart failure only in the first cycle. Other grade 3 or 4 toxicities were hypomagnesemia, anorexia, nausea, mucositis, liver enzyme elevation, fever, infection, and fatigue. There were no unexpected severe toxicities. Conclusion The toxicity profile of JPLT3-H was comparable to that of SIOPEL-4. Dose-dense cisplatin-based chemotherapy may be feasible among Japanese patients with high-risk hepatoblastoma.

Hepatoblastoma (HB) is the most common pediatric liver malignancy; however, hereditary predisposition and acquired molecular aberrations related to HB clinicopathological diversity are not well understood. Here, we perform an integrative genomic profiling of 163 pediatric liver tumors (154 HBs and nine hepatocellular carcinomas) based on the data acquired from a cohort study (JPLT-2). The total number of somatic mutations is precious low (0.52/Mb on exonic regions) but correlated with age at diagnosis. Telomerase reverse transcriptase (TERT) promoter mutations are prevalent in the tween HBs, selective in the transitional liver cell tumor (TLCT, > 8 years old). DNA methylation profiling reveals that classical HBs are characterized by the specific hypomethylated enhancers, which are enriched with binding sites for ASCL2, a regulatory transcription factor for definitive endoderm in Wnt-pathway. Prolonged upregulation of ASCL2, as well as fetal-liver-like methylation patterns of IGF2 promoters, suggests their “cell of origin” derived from the premature hepatoblast, similar to intestinal epithelial cells, which are highly proliferative. Systematic molecular profiling of HB is a promising approach for understanding the epigenetic drivers of hepatoblast carcinogenesis and deriving clues for risk stratification., While hepatoblastoma is the most common pediatric liver cancer, its molecular background has not been fully characterised. Here, the authors perform genomic and epigenomic profiling of 163 untreated pediatric liver tumours and suggest the upregulation of ASCL2 and methylation patterns of IGF2 promoters in driving hepatoblast carcinogenesis.

Background In Japan, allogeneic hematopoietic stem cell transplantation is widely performed for recurrent neuroblastomas. This retrospective study aimed to investigate the prognosis of recurrent neuroblastoma in Japan and explore the effectiveness of allogeneic hematopoietic stem cell transplantation. Methods Clinical characteristics and data on the treatment of patients with high-risk neuroblastoma who experienced first progression between 2003 and 2010 after attaining complete remission or partial remission were collected from hospitals participating in the Japanese Neuroblastoma Research Group. Results Data from 61 patients who fulfilled these criteria were collected. The median interval from disease onset to first progression was 19 months (range, 7–65 months), whereas the median observation time of the surviving patients was 18 months (range, 1–69 months). All patients were treated with chemotherapy, where 22 and 3 patients received allogeneic and autologous hematopoietic stem cell transplantation, respectively. Seven patients were alive in second complete remission, and 39 died, including two in complete remission. The 3-year progression-free survival and overall survival rates were 15.3% (SE: 6.1%) and 16.9% (SE: 6.5%), respectively. For patients with allogeneic hematopoietic stem cell transplantation, the 3-year progression-free survival and overall survival were 28.3% (standard error, 12.0%) and 24.3% (standard error, 11.5%), respectively, and for patients without allogeneic hematopoietic stem cell transplantation, the 3-year progression-free survival and overall survival were 6.0% (standard error 5.5%) and 12.0% (standard error 7.6%), respectively. The duration of initial remission (≥ 18 months) and implementation of allogeneic hematopoietic stem cell transplantation were independently predictive of progression-free survival (P = 0.002 and P = 0.017), whereas for overall survival, only allogeneic hematopoietic stem cell transplantation was predictive (P = 0.012). Conclusion Although allogeneic hematopoietic stem cell transplantation contributed to some improvement in prognosis, it was insufficient.

Pneumothorax and tumor-bronchial fistula are rare complications of pulmonary metastasis of osteosarcoma.We herein report the cases of 3 pediatric and adolescent patients who developed pneumothorax or tumor-bronchial fistula during treatment of pulmonary metastasis of osteosarcoma with chemotherapeutics or antiangiogenic agents. Two patients developed pneumothorax, and the other patient developed tumor-bronchial fistula. All of the patients finally underwent the surgery to treat their complications.Although it is not a curative surgery, surgery for pneumothorax and tumor-bronchial fistula is acceptable. The operative procedure should be considered on the basis of the predicted prognosis of the patient.

PURPOSEWe report here the outcomes and late effects of the Japanese Study Group for Pediatric Liver Tumors (JPLT)-2 protocol, on the basis of cisplatin-tetrahydropyranyl-adriamycin (CITA) with risk stratification according to the pretreatment extent of disease (PRETEXT) classification for hepatoblastoma (HB).PATIENTS AND METHODSFrom 1999 to 2012, 361 patients with untreated HB were enrolled. PRETEXT I/II patients were treated with up-front resection, followed by low-dose CITA (stratum 1) or received low-dose CITA, followed by surgery and postoperative chemotherapy (stratum 2). In the remaining patients, after 2 cycles of CITA, responders received the CITA regimen before resection (stratum 3), and nonresponders were switched to ifosfamide, pirarubicin, etoposide, and carboplatin (ITEC; stratum 4). Intensified chemotherapeutic regimens with autologous hematopoietic stem-cell transplantation (SCT) after resection were an optional treatment for patients with refractory/metastatic disease.RESULTSThe 5-year event-free and overall survival rates of HB patients were 74.2% and 89.9%, respectively, for stratum 1, 84.8% and 90.8%%, respectively, for stratum 2, 71.6% and 85.9%%, respectively, for stratum 3, and 59.1% and 67.3%%, respectively, for stratum 4. The outcomes for CITA responders were significantly better than those for nonresponders, whose outcomes remained poor despite salvage therapy with a second-line ITEC regimen or SCT. The late effects, ototoxicity, cardiotoxicity, and delayed growth, occurred in 61, 18, and 47 patients, respectively. Thirteen secondary malignant neoplasms (SMNs), including 10 leukemia, occurred, correlating with higher exposure to pirarubicin and younger age at diagnosis.CONCLUSIONThe JPLT-2 protocol achieved up-front resectability in PRETEXT I/II patients with no annotation factors, and satisfactory survival in patients who were CITA responders in the remaining patients. However, outcomes for CITA nonresponders were unsatisfactory, despite therapy intensification with ITEC regimens and SCT. JPLT-2 had a relatively low incidence of cardiotoxicity but high rates of SMNs.

Background: Esophageal leiomyomatosis (EL) is a rare benign tumor defined as a diffuse form of marked hypertrophy in the muscular layer of the esophagus. Relapses have been reported as a result of misdiagnoses of other tumors or achalasia, followed by inappropriate surgical intervention. The endoscopic approach is preferred because of its lesser degree of invasiveness and better cosmesis; however, its effectiveness for treatment of EL is unclear because these tumors are bulkier and more extensive than those in other esophageal diseases. Case presentation: We treated an 11-year-old girl who had been experiencing progressive dysphagia, vomiting, and coughing during sleep since the age of 4 years and was correctly diagnosed with EL using computed tomography and endoscopic ultrasonography. She was successfully treated with total minimally invasive esophagectomy (MIE), combining thoracoscopy and laparoscopy, in the prone position, without any complications or recurrence of symptoms. To our knowledge, this is the first case report of MIE for EL. A review of 84 EL cases (including the present case) revealed a rate of accurate preoperative diagnosis of only 23.8%. Esophagectomy should be employed because the recurrence rate of the non-esophagectomy cases, involving myotomy and tumorectomy, was significantly higher than that of the esophagectomy cases (57.9% vs. 7.7%, p = 0.002). Among 11 relapse cases in the non-esophagectomy cases, esophagectomy was performed in eight. Among the four relapse cases in the esophagectomy group, additional esophagectomy was necessary in three because of insufficient resection of the tumors at the primary esophagectomy. Conclusions: Multimodal imaging contributes to accurate diagnosis and assessment of the extent of the tumors, thus leading to the selection of the appropriate surgical intervention, i.e., radical esophagectomy. Total MIE in the prone position provides excellent exposure of the operative fields; our experience suggests that total MIE is beneficial for EL, as it is for other esophageal tumors. Keywords: Esophageal leiomyomatosis, Minimally invasive esophagectomy, Prone position, Achalasia, Case report, Review of literature

The Japanese Children’s Cancer Group (JCCG) Neuroblastoma Committee (JNBSG) conducted a phase II clinical trial for high-risk neuroblastoma treatment. We report the result of the protocol treatment and associated genomic aberration studies. JN-H-07 was a single-arm, late phase II trial for high-risk neuroblastoma treatment with open enrollment from June 2007 to February 2009. Eligible patients underwent five courses of induction chemotherapy followed by high-dose chemotherapy with hematopoietic stem cell rescue. Surgery for the primary tumor was scheduled after three or four courses of induction chemotherapy. Radiotherapy was administered to the primary tumor site and to any bone metastases present at the end of induction chemotherapy. The estimated 3-year progression-free and overall survival rates of the 50 patients enrolled were 36.5 ± 7.0 and 69.5 ± 6.6%, respectively. High-dose chemotherapy caused severe toxicity including three treatment-related deaths. In response to this, the high-dose chemotherapy regimen was modified during the trial by infusing melphalan before administering carboplatin and etoposide. The modified high-dose chemotherapy regimen was less toxic. Univariate analysis revealed that patients younger than 547 days and patients whose tumor showed a whole chromosomal gains / losses pattern had a significantly poor prognosis. Notably, the progression-free survival of cases with MYCN amplification were not inferior to those without MYCN amplification. The outcome of patients treated with the JN-H-07 protocol showed improvement over the results reported by previous studies conducted in Japan. Molecular and genetic profiling may enable a more precise stratification of the high-risk cohort.

Clear cell sarcoma of the kidney (CCSK) is the second most common renal malignancy in children. The prognosis is poorer in CCSK than in Wilms' tumor, and multimodal treatment including surgery, intensive chemotherapy, and radiation is required to improve the outcome for children with CCSK. Histological evaluation is required for the diagnosis. However, biopsies of tumors to obtain diagnostic specimens are not routinely performed because of the risk of spreading tumor cells during the procedure. Recently, internal tandem duplication (ITD) of BCOR has been recognized as a genetic hallmark of CCSK. We herein established a novel BCOR-ITD-specific polymerase chain reaction method with well-designed primers, and then performed a liquid biopsy for cell-free DNA (cfDNA) obtained from plasma of three children with nonmetastatic renal tumors (stage II) and from one control. BCOR-ITD was positively detected in the cfDNA of two cases, both of which were later diagnosed as CCSK based on histological feature of the resected tumor specimen, while it was not detected for a normal control and a patient diagnosed with Wilms' tumor. Our study is the first one of preoperative circulating tumor DNA assay in pediatric renal tumors. The liquid biopsy method enables less invasive, preoperative diagnosis of CCSK with no risk of tumor spillage, which can avoid iatrogenic upstaging.

Duodenal duplication cyst is not a common congenital anomaly and the pathophysiology may become very complicated if the cyst is situated at the ampulla of Vater. Here we report a very rare female case of duodenal duplication cyst at the ampulla of Vater, which caused acute pancreatitis due to massive protein plaques in the pancreatic duct. She had a past history of double duodenal atresia and underwent surgery as a neonate. The correct diagnosis could not be determined before the second operation at four years of age and the exact pathophysiology finally became apparent during the operation with a contrast medium study and duodenotomy. We discuss the complicated clinical features and diagnostic and treatment procedures before and during the operation.

The outcome of multimodal therapy for localized bladder rhabdomyosarcoma is quite good in terms of morbidity, and conservative surgery is generally recommended. However, in cases originating in the bladder neck, tumorectomy or partial cystectomy has adverse effects on bladder function. A 2-year-old girl underwent transurethral resection of a bladder tumor (TUR-BT), chemotherapy consisting of vincristine, actinomycin-D, and cyclophosphamide, and radiotherapy. She was in remission for 3 years when frequent urination became evident. Her bladder capacity and compliance were low; however, her urinary symptom was controlled using anticholinergic medication. Accordingly, TUR-BT could be an optional approach for bladder rhabdomyosarcoma. Keywords: Rhabdomyosarcoma, Transurethral resection, Conservative surgery