[Fanconi Anemia, Complementation Group D1 Caused by Biallelic Mutations of BRCA2 Gene--Case Report]. / Fanconiho anémie, komplementacní skupina D1 v dusledku bialelické mutace genu BRCA2--kazuistika.

Fanconi anemia is a rare autosomal recessive disorder, clinically and genetically heterogeneous, characterized by typical clinical features, such as short stature, microcephaly, skeletal abnormalities, abnormal skin pigmentations, developmental delay and congenital heart, kidney anomalies etc. Pancytopenia leading to bone marrow failure occurs in the first decade. Patients with Fanconi anemia have a high risk of hematologic malignancies and solid tumors. The diagnosis of Fanconi anemia is based on cytogenetic testing for increased rates of spontaneous chromosomal breakage and increased sensitivity to diepoxybutane or mitomycin C. Fanconi anemia is a heterogeneous disorder, at least 15 complementation groups are described, and 15 genes in which mutations are responsible for all of the 15 Fanconi anemia complementation groups have been identified. Unlike other Fanconi anemia complementation groups, for complementation group D1 (FANCD1), the bone marrow failure is not a typical feature, but early-onset leukemia and specific solid tumors, most often medulloblastoma and Wilms tumor, are typical for this complementation group.

[Neuropathological diagnostics in pediatric oncology from the clinical point of view]. / Neuropatologická diagnostika v detské onkologii pohledem klinika.

Treatment of pediatric brain tumors in children and adolescents is a tremendous challenge for the treating physicians, requiring a multidisciplinary approach and co-operation of multiple sub-specialities. Considerable progress in diagnostics and treatment of brain tumors has been made in recent years. In many brain tumors, especially embryonal brain tumors important, clinically relevant bio markers, were identified and are increasingly used in patient stratification into risk groups. Collaboration between clinicians, pathologists and molecular biologists is essential for successful therapy. This article gives some examples of collaboration in pediatric neuro-oncology.

Rhabdomyosarcoma: molecular analysis of Igf2, MyoD1 and Myogenin expression.

Rhabdomyosarcoma is the most common soft tissue sarcoma of childhood. There are two major histopathological types of RMS ­ embryonal (eRMS) and alveolar (aRMS). A molecular study of Igf2, MyoD1 and Myogenin was performed to determine the expression profiles and to assess the possible utility of these genes as potential treatment targets. Patients with RMS showed up to 100-fold increase of Igf2 transcription in comparison with normal skeletal muscle. Our data suggest that overexpression of Igf2 occurs in RMS of both histological subtypes. No correlation between the results of Igf2 mRNA expression and LOH at the 11p15 region (p= 0.12) was observed, but there was a trend of a higher expression of Igf2 mRNA in RMS samples with LOH. We observed a high level of MyoD1 mRNA in both aRMS and eRMS, and we detected a similar level of MyoD1 mRNA in RMS and normal skeletal muscles. There was a correlation between the results of MyoD1 mRNA expression and LOH at the 11p15 region.We did not observe any statistical difference in the level of Myogenin mRNA in the subgroups of RMS. Analogous to MyoD1, we observed a similar level of Myogenin mRNA in RMS and normal skeletal muscles.

[Radical surgery and intensive chemotherapy are necessary for successful treatment of osteosarcoma]. / Radikální operacní výkon a intenzivní chemoterapie jsou podmínkou úspesné lécby osteosarkomu.

BACKGROUND: We evaluated the therapeutic results in 44 patients (17 girls and 27 boys) with osteosarcoma from 1997 to 2006.Their average age was 12.8 years (2.5-20.2). 41 patients had localised disease and 3 had primary metastases. PATIENTS AND METHODS: We treated our 44 patients using CCG 7921 POG 9351 INT 0133, the therapeutic protocol of the North American cooperative Children's Oncology Group.The median of the follow up was 5.5 years (2-11 years). RESULTS: 40 patients went into complete remission. 19 patients suffered relapses. Of these, 17 patients died - 15 progressed, 1 died due to treatment-related toxicity, 1 died due to secondary acute myeloid leukaemia. As a whole, the patients had a 5-year overall survival rate (OS) of 58.4% and a 5-year event free survival rate (EFS) of 46.7%. The patients with localised extremity osteosarcoma (n = 40) had a 5-year EFS rate of 51%. The patients with good histological response (n = 22) had a 5-year EFS rate of 63.6%, while patients with poor histological response (n = 18) achieved a 5-year EFS rate of 30.5% (p = 0.009). CONCLUSION: The results of treatment of patients with localised extremity osteosarcoma and patients with good histological response to preoperative treatment were very good. The prognosis of patients with axial localisation and metastatic involvement was poor.

[Clinical relevance of chromosomal aberrations in bone and soft tissue tumors in children and young adults]. / Klinický význam chromozomálních zmen u nádoru kostí a mekkých tkání detí a mladistvých.

BACKGROUND: We present the results of a cytogenetic and molecular cytogenetic analysis of a series of patients with bone and soft tissue tumors. PATIENTS ANDMETHODS: We analyzed a cohort of 26 patients with Ewing sarcoma/PNET, 15 patients with rhabdomyosarcoma, 5 with synovial sarcoma and one patient with an undifferentiated sarcoma using the cytogenetic and molecular cytogenetic techniques M-FISH and arrayCGH. RESULTS: We found nonrandom chromosomal structural and numerical changes with diagnostic and prognostic relevance in most patients. Eight patients with ES/PNET had only a t(11;22)(q24;q12), eight patients had secondary aberrations as well and six had only secondary aberrations. In the RMS patients we detected the t(1;13)(p36;q14) once and the t(2;13)(q35;q14) four times, both of them characteristic for the alveolar subtype with poor prognosis and numerical aberrations, characteristic for the embryonal subtype, in five patients. Four patients with synovial sarcoma had the diagnostic t(X;18)(p11.2;q11.2), one of them had a complex karyotype with a complex t(X;18;21) (p11.2;q11.2;q11.2) together with t(2;5)(q24-32;p13-14) and t(12;20)(p11;q13). We correlated the karyotype of cancer cells with histopathologic morphologic analysis, clinical outcome and foreign published results. CONCLUSION: Cytogenetic and molecular cytogenetic analysis is a valuable diagnostic tool in bone and soft tissue tumors, especially in less differentiated subtypes, and as such it should be an integral part of curative care.

Rhabdomyosarcoma: molecular diagnostics of patients classified by morphology and immunohistochemistry with emphasis on bone marrow and purged peripheral blood progenitor cells involvement.

Two histologically distinct subtypes of rhabdomyosarcomas (RMS), embryonal and alveolar, are different in many aspects, such as age distribution, primary site, and clinical outcome. We analyzed a group of 30 patients with RMS. The aim was to broaden the spectrum of diagnostic tools in evaluating the primary tumors, their recurrences and/or metastases, and to extend the diagnostic boundary to bone marrow and purged peripheral progenitor blood cell samples. We have performed the RT-PCR assay to analyze RMS for the presence of expression of MyoD1 gene and for the presence of chimeric transcripts PAX3/FKHR or PAX7/FKHR. MyoD1 gene expression was found in all 30 patients in samples from primary tumors. The chimeric transcripts PAX/FKHR were identified in 13 of 15 patients with alveolar RMS. Furthermore, the fusion transcript PAX7/FKHR was identified in 2 of 15 patients with RMS classified as embryonal by histology. Bone marrow samples (12) and peripheral blood progenitor cell specimens (13) in ten patients were examined by RT-PCR. We were able to identify 7 patients with bone marrow involvement and/or with contamination of peripheral blood progenitor cells by the tumor cells. We demonstrate that employing molecular diagnostics has an impact on staging, therapy monitoring and recognition of malignant cells at the tumor resection margins.

[Mixed germ cell tumours of the ovary in childhood and adolescence]. / Smísené germinální nádory ovaria u detí a dospívajících. Retrospektivní klinicko-patologická studie.

Mixed germ cell tumours of the ovary are rare malignant neoplasms containing combinations of two or more types of germ cell elements. The aim of the study was to review biopsy examinations, medical records, treatment strategy, follow-up and outcome of all girls treated for mixed germ cell tumour of the ovary at the Department of Pediatric Oncology, University Hospital Motol during the period 1979-2002. Archival slides of all tumours were reviewed and tumours were classified according to the WHO system. The clinical data on surgical treatment, chemotherapy and radiotherapy used and follow-up information were obtained in all girls. The staging was reviewed retrospectively on the basis of surgical and pathological findings and results of imaging investigations, and it was outlined according to the most recent FIGO criteria and TNM classification. Sixteen girls with mixed germ cell tumour of the ovary, age range 3 years 11 months to 17 years 8 months (median 12 years) were treated. All girls presented with unilateral tumour of the ovary and all underwent surgery as an initial treatment. The most common presenting symptom was abdominal pain, occurring in ten patients. The original diagnosis of mixed histology was confirmed in all cases; in five cases the tumour contained three histologic components, in eleven cases the tumour consisted of two germ cell types. All tumours contained elements of yolk sac tumour, followed by immature teratoma, embryonal carcinoma, dysgerminoma and mature teratoma. At the time of diagnosis three patients had stage I disease, four patients stage II, seven stage III and two stage IV disease. All patients were treated with chemotherapy after surgery, predominantly with platinum-based regimens (PVB, BEP). Three patients treated initially with MAC (metothrexate, dactinomycin, cyclophosphamide) were diagnosed in the early eighties. In seven girls with advanced disease treated in the early years, radiotherapy was administered to the pelvis or whole abdomen. Overall survival and event-free survival were 80% and 81.3% respectively (median follow-up time 7.6 years). Three patients have died from the disease, two progressed on treatment (MAC), one girl relapsed three months after finishing therapy, no further therapy was administered. One girl underwent resection of tumour of her remaining ovary 24 months after original diagnosis. Histology showed mixed serous and mucinous cystadenoma. The latest examinations revealed that all other patients were in good health. Microscopic examination should be extensive and careful to find out all types of malignant germ cell elements. Platinum based chemotherapy is effective in the management of children and adolescents with mixed germ cell tumors of the ovary. Chemosensitivity of these tumours allows most girls to have conservative surgery with possible preservation of reproductive function.

[Ovarian dysgerminoma in children and adolescents. Retrospective clinico-pathologic study]. / Dysgerminomy ovaria u detí a dospívajících. Retrospektivní klinicko-patologická studie.

BACKGROUND: To review the treatment strategy, follow up and outcome for all patients with pure ovarian dysgerminoma treated in childhood and adolescence. METHODS AND RESULTS: Twenty-one patients younger than 18 years were treated between 1979-2002 in Faculty Hospital Motol for newly diagnosed pure ovarian dysgerminoma. Patients were included into the cohort on the basis of revision of archival biopsy specimens deposited in Institute of Pathology and in Molecular Medicine tumor registry. The staging was reviewed retrospectively on the basis of surgical and pathological findings and on results of imaging investigations and outlined according to the TNM and International Federation of Gynecology and Obstetrics (FIGO) classification. The median age at the time of diagnosis was 12.5 years (range 6 years, 5 months--17 years, 11 months). There were ten FIGO stage IA tumors, one stage IB, two of stage IIC, one stage IIIB and seven IIIC tumors. All patients, except two girls with bilateral dysgerminoma, underwent unilateral adnexectomy or ovarectomy. Ten girls were treated postoperatively with chemotherapy, eight with chemotherapy and radiotherapy (eleven with cisplatine based chemotherapy). Three girls with dysgerminoma confined to the ovary (stage IA) have not received adjuvant chemotherapy. With a median follow up 7.1 years all girls remained continuously disease free. The 5-year overall and event free survival is 100%. Majority of patients does not have severe treatment sequelae, three pregnancies have occurred so far. CONCLUSIONS: Most patients with dysgerminoma, including those with metastases can expect cure when treated with conservative surgery and cisplatine based chemotherapy. Reduction of treatment toxicity and preservation of reproductive function is a main task. The girls with dysgerminoma confined to the ovary (stage IA) can be treated with fertility sparing surgery, other should be treated with cisplatine based chemotherapy.

[Manipulation of hematopoietic stem cell grafts and their use in clinical practice]. / Manipulace se stepy hematopoetických progenitorových bunek a jejich pouzití v klinické praxi.

Autologous stem cell transplantation has been successfully used in treatment of various hematological malignancies and solid tumors in children and adults. Published data have confirmed that bone marrow harvests and peripheral blood stem cell collections frequently contain a significant number of tumor cells. Contaminating tumor cells can contribute to the disease relapse in posttransplant period, so attempts are made to eliminate contaminating tumor cells from autografts. In the case of allogenic transplantation, T-lymphocytes depletion from graft decreases the risk of the graft versus host disease after transplantation. In this article we comment techniques available and method used for elimination of tumor cells. Commentary is aimed on potential benefits and risks of every method.

Significance of P-glycoprotein expression in childhood malignant tumors.

Resistance to chemotherapy significantly affects the treatment results in various cancers. Multidrug resistance caused by P-glycoprotein expression is now widely studied in human malignancies. We present the results of P-glycoprotein expression examination in 91 tumor tissue samples obtained from children treated for different malignant tumors in the Dept. of Pediatric Oncology, Prague. The correlation between the level of P-glycoprotein expression and tumor histology, clinical outcome, use of therapy, relapse rate and metastatic disease was made. P-glycoprotein expression was found significantly more frequent in soft tissue sarcomas, neuroblastomas, and hepatoblastomas, and generally in disseminated disease. On the contrary, a high expression of P-glycoprotein was not found in malignant brain tumors and nephroblastomas. The data strongly support the possibility that the percentage of P-glycoprotein expressing cells in selected tumors (soft tissue sarcomas, neuroblastomas), may have a clinical importance.

Detection of minimal bone marrow infiltration in patients with localized and metastatic Ewing sarcoma using RT-PCR.

Ewing sarcoma and related neoplasias are characterized by the presence of specific chromosomal translocations resulting in EWS/ETS gene rearrangements. Created EWS/ETS-oncogene fusion transcripts can be detected in up to 98% of ESFT and provide tumour-specific markers useful in diagnostics. Using RT-PCR for detection of this aberration we can reveal minimal amounts of tumour cells contaminating BM, blood or apheresis products. We have examined BM samples from 22 patients (21 newly diagnosed and one recurrent disease) with histologically confirmed ESFT for the presence of contaminating tumour cells in BM at the time of diagnosis. Sixteen patients presented with localized disease, six had distant metastases at the first presentation. Ewing sarcoma cells were detected in the BM of 5/16 (31%) patients with localized disease and 3/6 (50%) with clinically detectable metastases at diagnosis. BM smears prepared from the same aspirates evaluated by light microscopy were all negative, even in two patients with multiple bone disease. We have confirmed the high sensitivity of the RT-PCR assay for detection of minimal BM infiltration in localized and metastatic ESFT. We have found that more than a quarter of patients with localized ESFT have minimal BM infiltration. Although the clinical significance of the minimal disease detected at the molecular level remains unknown, RT-PCR evaluation may enable better stratification of patients into risk groups in the future.

Gene aberrations in childhood brain tumors.

We present the results of the examination of prognostic markers in 40 children suffering from brain tumors. Prognostic markers such as amplification of the N-myc and c-myc, deletion of the 17p, and DNA ploidy are indispensable factors for the determination of diagnosis. An increased number of c-myc gene copies was found in malignant brain tumors, especially embryonal, more often than reported in the literature. N-myc amplification occurs in our group seldom, but it seems to be a sign of worse prognosis in glial and embryonal brain tumors. DNA aneuploidy was not found very frequently, but in high-grade tumors only.

[Detection of minimal residual disease in Ewing's sarcoma using RT-PCR]. / Detekce minimální reziduální nemoci u Ewingova sarkomu pomocí RT-PCR.

BACKGROUND: More than 90% of Ewing's sarcomas (ES) contain a fusion of the EWS and FLI-1 genes, due to the t(11;22)(q23;q12) translocation. At the molecular level, the EWS-FLI-1 rearrangement shows great diversity. Specifically, many different combinations of exons from EWS-FLI-1 encode in-frame fusion transcripts and result in differences in length and composition of the chimeric protein, which function as an oncogenic aberrant transcription factor. The finding of this translocation gives evidence for the presence of ES cells. The aim of this prospective study was to verify applicability of the RT-PCR method for the detection of minimal residual disease in patients with ES. METHODS AND RESULTS: Conditions for the detection of Ewing's sarcoma cells by means of the reverse-transcriptase polymerase chain reaction (RT-PCR) at fusion transcripts in peripheral blood, bone marrow (BM) and autologous hematopoietic stem cell grafts in patients with ES were appointed. 31 samples of BM, 5 samples of blood and 7 peripheral blood grafts obtained from 23 patients were investigated. Presence of tumor cells was identified in 7 BM samples from 7 different patients (31 samples from 16 patients), all the peripheral blood and graft samples were negative. CONCLUSIONS: The high sensitivity of RT-PCR method in detection of cells bearing t(11;22)(q23;q12) was demonstrated in the experimental model and clinical samples. Likewise the literary statements, the RT-PCR method was found to be more sensitive than cytology.