Inequalities in diagnosis and registration of pediatric very rare tumors: a European study on pleuropulmonary blastoma.

Very rare tumors (VRTs) account for up to 11% of childhood cancers. Dedicated national groups and registries only exist in some European countries. Pleuropulmonary blastoma (PPB) is a very rare intrathoracic pediatric tumor with a potentially severe prognosis. Due to its rarity, it sometimes goes unrecognized. We investigated PPB diagnostic capability and possible correlations between diagnostic performance and VRT-dedicated activities. The number of cases of PPB registered between 2000 and 2014 at pediatric oncology centers in Europe was compared with the number of expected cases. Data sources included VRT registries, population-based cancer registries, and hospital registries. Data were obtained for 25 countries, grouped into 4 geographical regions. The expected cases were 111, and the observed cases were 129. The observed-to-expected ratio was 1.86 for Northern Europe, 1.33 for Southern Europe, 1.22 for Central Europe, and 0.65 for Eastern Europe. More cases than expected were registered in all countries with an official VRT registry.Conclusion: The number of cases observed is consistent with expectations, but disparities exist across Europe. Difficulties in diagnosing PPB emerged in most Eastern countries. The incidence rate of PPB may be underestimated. The creation of VRT-dedicated groups and a European Registry for VRTs could help to reduce inequalities.What is Known:• Very rare pediatric tumors are often not recognized, despite representing almost 11% of childhood cancers .• Pleuropulmonary blastoma is a rare pediatric tumor with a poor prognosis.What is New:• The ability to diagnose and register pleuropulmonary blastoma varies in Europe.Registries dedicated to very rare pediatric tumors improve the diagnostic rates.• The incidence rate of pleuropulmonary blastoma may currently be underestimated.

New national recommendations for the treatment of pediatric differentiated thyroid carcinoma in the Netherlands.

BACKGROUND: Currently, there are no European recommendations for the management of pediatric thyroid cancer. Other current international guidelines are not completely concordant. In addition, medical regulations differ between, for instance, the US and Europe. We aimed to develop new, easily accessible national recommendations for differentiated thyroid carcinoma (DTC) patients <18 years of age in the Netherlands as a first step toward a harmonized European Recommendation. METHODS: A multidisciplinary working group was formed including pediatric and adult endocrinologists, a pediatric radiologist, a pathologist, endocrine surgeons, pediatric surgeons, pediatric oncologists, nuclear medicine physicians, a clinical geneticist and a patient representative. A systematic literature search was conducted for all existing guidelines and review articles for pediatric DTC from 2000 until February 2019. The Appraisal of Guidelines, Research and Evaluation (AGREE) instrument was used for assessing quality of the articles. All were compared to determine dis- and concordances. The American Thyroid Association (ATA) pediatric guideline 2015 was used as framework to develop specific Dutch recommendations. Discussion points based upon expert opinion and current treatment management of DTC in children in the Netherlands were identified and elaborated. RESULTS: Based on the most recent evidence combined with expert opinion, a 2020 Dutch recommendation for pediatric DTC was written and published as an online interactive decision tree (www.oncoguide.nl). CONCLUSION: Pediatric DTC requires a multidisciplinary approach. The 2020 Dutch Pediatric DTC Recommendation can be used as a starting point for the development of a collaborative European recommendation for treatment of pediatric DTC.

Cushing syndrome as presenting symptom of calcifying nested stromal-epithelial tumor of the liver in an adolescent boy: a case report.

BACKGROUND: Ectopic adrenocorticotropic hormone-producing primary liver tumors are rare, especially in children. We report the case of an adolescent boy of mixed Dutch and Moroccan descent with an adrenocorticotropic hormone-producing calcifying nested stromal-epithelial tumor with long-term follow-up. Thus far, only two such cases have been reported. CASE PRESENTATION: A 16-year-old boy of mixed Dutch and Moroccan descent presented with Cushing syndrome and a palpable abdominal mass. A calcifying nested stromal-epithelial tumor was diagnosed. Postoperatively, his plasma adrenocorticotropic hormone concentration normalized. He remains in complete remission 13 years after tumor resection. CONCLUSIONS: Calcifying nested stromal-epithelial tumor should be in the differential diagnosis of liver tumors, especially if associated with Cushing syndrome as significant morbidity and mortality may be associated. Literature on the topics involved is comprehensively reviewed.

Pre-operative diagnostic biopsy and surgery in paediatric liver tumours--the Amsterdam experience.

AIM: To report 24 years of pre-treatment biopsy and surgical experience in primary liver tumours in children. METHODS: Between 1979 and 2003, 53 children presented with a primary liver tumour of whom 48 who underwent surgical resection were evaluated (two died, two were unresectable, and one was transplanted). Biopsy data, per- and post-operative complications, mortality, and survival were retrospectively reviewed. RESULTS: Benign tumours were diagnosed in eight patients. Surgical resection for a malignant tumour was performed in 40 patients (26 hepatoblastomas (HB), eight hepatocellular carcinomas (HCC) (four had fibrolamellar HCC), three rhabdomyosarcomas (RMS), one neuroblastoma, one non-hodgkin lymphoma (NHL), and one teratoma). Primary resection was performed in one HB, and four HCCs. The cumulative survival without evidence of disease was 73% for HB (median 7 years) and 88% for HCC (median 3.5 years). CONCLUSION: The treatment results are comparable with those of larger international series except for HCC. The existing diagnostic pitfalls in differentiating between the various liver malignancies justify the use of a diagnostic biopsy.

First line targeted radiotherapy, a new concept in the treatment of advanced stage neuroblastoma.

33 previously untreated advanced stage neuroblastoma patients were treated with [131I]meta-iodobenzylguanidine (MIBG). The number of treatments varied between 2 and 7 per patient (mean 3). Toxicity was seldom severe. Only thrombocytopenia WHO-grade 4 was noticed. Response was documented before surgery for the primary tumour was performed. There was one complete response (CR), 18 partial responses (PR), 11 had stable disease (SD) and 3 had progressive disease (PD). After MIBG therapy and surgery, 12 of 33 patients achieved a CR. This approach is feasible, comparable to multidrug chemotherapy in efficacy and less toxic. Long term results are not known yet.

[Familial cyclic neutropenia]. / Familiáris megjelenésü ciklikus neutropenia.

This rare disorder characterized by regular periodic oscillations in the number of peripheral neutrophils from normal to neutropenic levels. A case of a fourteen years old boy is presented who developed the disease at age of four years. Neutropenic periods appeared at intervals of 21 days and were associated with recurrent infections--gingivitis, stomatitis, conjunctivitis. The possible mechanism of impaired granulopoiesis and different therapeutic approaches are discussed.

[Progression of cutaneous T cell lymphoma in leukemia]. / Cutan T-sejtes lymphoma progressiója leukaemiába.

Transition of a (probably primary) cutaneous non-Hodgkin's lymphoma to T-stem cell leukaemia was observed in a case. Unusual clinical features, histological and laboratory data hampered the diagnosis-making of this rare disease. Using the ALL-BFM 90 HRG protocoll complete remission was achieved. Under the treatment varicella-zoster virus encephalitis took place.

[Polycytemia vera in an 11-year old girl]. / Valódi polycythaemia 11 éves leányban.

The case of an 11 year old girl with three line type of polycythaemia vera, with 4 cm splenomegaly and a plethoric complexion is presented. Peripheral blood values were as follows: RBC: 7.75 x 10(12)/l, Hb: 18.8 g/l, WBC: 15.2 x 10(9)/l, platelets: 920 x 10(9)/l. Serum erythropoietin level: < 1 mU/ml. In vitro, erythroid colonies developed from the bone marrow in the absence of added erythropoetin. For three years the haematocrit value has been controlled by regular venesections. Since extreme thrombocytosis developed, the treatment was continued with interferon alpha. Different treatment protocols are discussed.

[The incidence of iron deficiency in Hungary among children aged 4-6 years]. / A vashiánybetegség gyakorisága Magyarországon a 4-6 éves gyermekek között.

The authors found, that the incidence of hypochromic, microcytic anaemia was 4 percent, and more than half of the children were suffered from iron deficiency. The causes are the inadequate daily iron uptake and/or increase iron requirement. It is very important to increase the iron content of the food and/or the prophylactic or therapeutic iron treatment.

Relapses in hepatoblastoma patients: clinical characteristics and outcome--experience of the International Childhood Liver Tumour Strategy Group (SIOPEL).

PURPOSE: To analyse the clinical characteristics and outcome of hepatoblastoma (HB) patients who relapsed after enrolment on SIOPEL studies 1-3. PATIENTS AND METHODS: Analysis of clinical data of all 59 patients (pts) registered in SIOPEL 1-3 studies, who relapsed after achieving complete remission (CR). RESULTS: The median time from the initial diagnosis to relapse was 12 months (4-115 m). The site of relapse was lung N=27, liver N=21, both liver and lung N=5 and other N=5 (missing data-MD: 1 patient). All but 9 pts had an alpha-fetoprotein level >10 ng/mL at the time of relapse. Treatment of the relapse included chemotherapy and surgery N=25, chemotherapy alone N=21, surgery alone N=7 and only palliative treatment N=5 (MD: 1 pt). Overall, 31 pts (52%) achieved a second CR. With a median follow-up of 83 months, 23 pts are alive, (18 in 2nd CR, 5 after a second relapse) and 36 pts have died (35 from disease and 1 from complications). Three-year event-free survival and overall survival are 34% and 43% respectively (95% confidence interval [CI] 0.28-0.69). The main factors associated with a good outcome were PRETEXT group I-III at diagnosis, a high AFP level at relapse and relapse treatment including both chemotherapy and surgery. CONCLUSION: Relapses in HB are rare events occurring in less than 12% of pts after CR. Combined treatment with chemotherapy and surgical removal of the tumour is essential for long-term survival.

Fibrolamellar variant of hepatocellular carcinoma does not have a better survival than conventional hepatocellular carcinoma--results and treatment recommendations from the Childhood Liver Tumour Strategy Group (SIOPEL) experience.

PURPOSE: Fibrolamellar hepatocellular carcinoma (FL-HCC) and conventional hepatocellular carcinoma (HCC) cases in two consecutive paediatric HCC trials were analysed to compare outcome and derive treatment implications. PATIENTS AND METHODS: Data of 24 FL-HCC (24% PRETEXT IV) and 38 HCC (42% PRETEXT IV) cases from SIOPEL-2 and -3 (1995-1998, 1998-2006) were analysed. Patients were treated according to SIOPEL-2 and -3 high-risk protocol (carboplatin+doxorubicin alternating with cisplatin; seven preoperative, three postoperative cycles) or with primary surgery followed by chemotherapy as indicated. RESULTS: Thirteen of 24 FL-HCC (54%) and 32/38 HCC (84%) were initially treated with chemotherapy. Eight FL-HCC (33%) and five HCC patients (13%) had primary surgery. Partial response was observed in 31% of FL-HCC versus 53% of HCC patients (p=0.17). Complete resection was achieved in ten FL-HCC and seven HCC patients (p=0.08). Three-year event free survival (EFS) was 22% for FL-HCC versus 28% for HCC. Overall survival (OS) was not significantly different at 3 years follow up (42% for FL-HCC versus 33% for HCC, p=0.24). EFS/OS Kaplan-Meier curves did not differ significantly, with median follow up of 43 (FL-HCC) and 60 (HCC) months. No significant correlation was found between potential prognostic factors and OS. In the entire cohort nine out of 23 (39%) patients with complete resection or orthotopic liver transplantation versus 34/39 (87%) without successful surgical treatment, died. CONCLUSIONS: Long-term OS in FL-HCC and HCC is similar. With low response rates, complete resection remains the treatment of choice.

Identification of an active reverse transcriptase enzyme encoded by a human endogenous HERV-K retrovirus.

Of the numerous endogenous retroviral elements that are present in the human genome, the abundant HERV-K family is distinct because several members are transcriptionally active and coding for biologically active proteins. A detailed phylogeny of the HERV-K family based on the partial sequence of the reverse transcriptase (RT) gene revealed a high incidence of an intact RT open reading frame within the HML-2 subgroup of HERV-K elements. In this study, we report the cloning of six full-length HML-2 RT genes, of which five contain an uninterrupted open reading frame. The RT enzymes were expressed as glutathione S-transferase fusion proteins in Escherichia coli, and several HERV-K RT enzymes demonstrated polymerase as well as RNase H activity. Several biochemical properties of the RT polymerase were analyzed, including the template requirements and optimal reaction conditions (temperature, type of divalent cation). Inspection of the nucleotide sequence of the HERV-K RT genes demonstrated a mosaic structure, suggesting that a high level of genetic recombination has occurred in this virus family, which is a hallmark of replication by means of reverse transcription. The selective pressure to maintain the RT coding potential is illustrated by the sequence of a particular HERV-K isolate that contains three 1-nucleotide deletions within a small RT segment, thus maintaining the open reading frame. These combined results may suggest that these endogenous RT enzymes still have a biological function. It is possible that the RT activity was involved in the spread of this major class of retroelements by retrotransposition, and in fact it cannot be excluded that this retrovirus group is still mobile. The endogenous RT activity may also have been involved in the shaping of the human genome, e.g., by formation of pseudogenes.

Treatment of childhood Hodgkin's disease without radiotherapy.

BACKGROUND: To minimize the side effects of treatment in children with Hodgkin disease (HD), chemotherapy was given without radiotherapy. PATIENTS AND METHODS: From 1975 to 1984, 21 patients with HD having lymph nodes < 4 cm were treated with six MOPP courses. From 1984 to 1987, all children presenting with HD (n = 17) were given six ABVD courses. From 1987 to 1993 all children (n = 21) were treated with six alternating ABVD and MOPP courses. RESULTS: MOPP-treated children showed an event-free survival (EFS) of 91%, overall survival, 100%; ABVD-treated children had an EFS of 70%, overall survival, 94%; ABVD-MOPP-treated children had an EFS of 91% and an overall survival of 91%. Two cases developed a second malignancy. Toxicity was low. CONCLUSIONS: In children, ABVD-MOPP treatment gives a good survival, and toxicity is low. Radiotherapy is not needed to treat HD in children.

Evolutionary relationships within a subgroup of HERV-K-related human endogenous retroviruses.

The prototype endogenous retrovirus HERV-K10 was identified in the human genome by its homology to the exogenous mouse mammary tumour virus. By analysis of a short 244 bp segment of the reverse transcriptase (RT) gene of other HERV-K10-like sequences, it has become clear that these elements represent an extended family consisting of multiple groups (the HML-1 to HML-6 subgroups). Some of these elements are transcriptionally active and contain an intact open reading frame for the RT protein, raising the possibility that this family is still expanding through retrotransposition. To better define the relationship of these endogenous retroviruses, we identified ten new members of the HML-2 subgroup. PCR was used to amplify reverse-transcribed RNA of a 595 bp region of the RT gene in a variety of human cell samples, including normal and leukaemic bone marrow and peripheral blood, placenta cells and a transformed T cell line. We provide an extensive phylogenetic analysis of the relationships for this cluster of HERV-K-related endogenous retroviral elements. Nucleotide diversity values for nonsynonymous versus synonymous codon positions indicate that moderately strong selection is or was operating on these retroviral RT gene segments. The evolution of this class of endogenous retroelements is discussed.

Biased nucleotide composition of the genome of HERV-K related endogenous retroviruses and its evolutionary implications.

The human genome contains a large number of sequences that belong to the HERV-K family of human endogenous retroviruses. Most of these elements are likely remnants of ancient infections by ancestral exogenous retroviruses. To obtain further insight into the evolutionary history and molecular mechanisms responsible for the diversity of the human HERV-K elements, we analyzed several aspects of their genome structure. The nucleotide composition of the HERV-K genome was found to be highly biased and asymmetric, with an abundance of the A nucleotide in the viral (+) strand. A similar trend has been reported for the genomes of several exogenous retroviruses, with different nucleotides as the preferred building block. Other genome characteristics that were reported previously for actively replicating retroviruses are also apparent for the endogenous HERV-K virus. In particular, we observed suppression of the dinucleotide CpG, which represents potential methylation sites, and a strong preference for synonymous substitutions within the open reading frame of the reverse transcriptase (RT) enzyme. Furthermore, the mutational spectrum of the HERV-K RT enzyme was evaluated by nucleotide sequence comparison of 34 available elements. Interestingly, this analysis revealed a striking similarity with the mutational pattern of the HIV-1 RT enzyme, with a preference for G-to-A and C-to-T transitions. It is proposed that the mutational bias of the HERV-K RT enzyme played a role in the shaping of this retroviral genome, which was actively replicating more than 30 million years ago. This effect can still be observed in the contemporary endogenous HERV-K elements.

Favorable outcome after 1-year treatment of childhood T-cell lymphoma/T-cell acute lymphoblastic leukemia.

BACKGROUND: For T-malignancies in children a poor prognosis is reported. In these malignancies a combination of lymphoma and leukemia is commonly seen at presentation and most patients are treated according to protocols for acute lymphoblastic leukemia (ALL). These protocols are often designed for the majority of ALL cases, i.e., progenitor-B-ALL. In pediatric lymphoblastic non-Hodgkin's lymphoma without bone marrow infiltration various protocols have been used. The most frequently reported regimens show variable survival rates between 40 and 75%. PATIENTS AND METHODS: From 1989 we have treated 32 consecutive patients with T-cell malignancies, irrespective of localization, with a protocol consisting of a 4-agent induction treatment followed by high doses of methotrexate, and cytosine-arabinoside and intensified bleomycin, adriamycin, cyclophosphamide, vin cristin, prednisone (BACOP) courses. Treatment duration for each patient was 1 year. Twenty-one of the 32 patients had stage IV disease. Follow-up ranged from 1.6 to 7.6 years (median 4.2 years). RESULTS: Overall event-free survival (EFS) was 72%, while in those with stage IV disease it was 67%. No therapy-related deaths occurred. Neither stage, initial leukocyte value, mediastinal involvement, bone marrow involvement, nor the presence of CD1, CD3, CD4, CD8, or CD10 epitopes was prognostically significant. Evaluation of toxicity revealed a minimal decrease of carbon monoxide diffusion and cardiac shortening fraction. CONCLUSION: A relatively short but intensive chemotherapy can be used in T-cell malignancies. The EFS is satisfying, but larger studies are needed.

Mutational analysis of Bax and Bcl-2 in childhood acute lymphoblastic leukaemia.

In childhood acute lymphoblastic leukaemia there are large interpatient variations in levels of the apoptosis-regulating proteins Bax and Bcl-2, but the molecular basis for this variation is unknown. Point-mutations in bax have been reported in cell lines derived from haematological malignancies. Frameshift mutations, which result in reduced Bax levels, have also been found in colon cancer of the microsatellite mutator phenotype. Bcl-2 overexpression, or gain of function mutations in the open reading frame (ORF) or in the translational repressor, the upstream ORF(uORF) of bcl-2, might also be important in deregulating its function or expression. We have therefore analyzed 21 bone marrow aspirates from untreated childhood acute lymphoblastic leukaemia and 2 from myeloid leukaemia for mutations in box and bcl-2. DNA sequence analysis of the ORFs of bax and bcl-2 and of the uORF of bcl-2 revealed no mutations, despite the large range in expression levels. Thus, mutations within the (u)ORFs of bax and bcl-2 that (in)activate or deregulate Bax and Bcl-2 are infrequent in primary childhood acute leukaemia and do not play a major role in regulation of the encoded proteins in this disease.