Functional inactivation of the WTX gene is not a frequent event in Wilms' tumors.

For many years the precise genetic etiology of the majority of Wilms' tumors has remained unexplained. Recently, the WTX gene, mapped to chromosome Xq11.1, has been reported to be lost or mutated in approximately one-third of Wilms' tumors. Moreover, in female cases, the somatically inactivated alleles were found to invariantly derive from the active chromosome X. Consequently, WTX has been proposed as a 'one-hit' tumor suppressor gene. To provide further insights on the contribution of WTX to the development of the disease, we have examined 102 Wilms' tumors, obtained from 43 male and 57 female patients. Quantitative PCR analyses detected WTX deletions in 5 of 45 (11%) tumors from males, whereas loss of heterozygosity at WTX-linked microsatellites was observed in 9 tumors from 50 informative females (19%). However, in the latter group, using a combination of HUMARA assay and bisulfite-modified DNA sequencing, we found that the deletion affected the active chromosome X only in two cases (4%). Sequence analyses detected an inactivating somatic mutation of WTX in a single tumor, in which a strongly reduced expression of the mutant allele respect to the wild-type allele was observed, a finding not consistent with its localization on the active chromosome X. Overall, a functional somatic nullizygosity of the WTX gene was ascertained only in seven of the Wilms' tumors included in the study (approximately 7%). Our findings indicate that previously reported estimates on the proportion of Wilms' tumors due to WTX alterations should be reconsidered.

Treatment of pediatric non-Hodgkin lymphomas in a country with limited resources: results of the first national protocol in Nicaragua.

We report the results of a protocol for the diagnosis and treatment of pediatric non-Hodgkin lymphomas (NHL) conducted in Nicaragua in the context of an international collaborative program. Fifty-three children with NHL treated between 1996 and 2003 were retrospectively evaluated. Therapy was designed based on local drug availability and affordability with dose and schedule adaptations for Burkitt and lymphoblastic lymphomas. With a median follow-up of 3 years, the projected 9-year overall survival was 63% and event-free survival 53%. The treatment was efficacious, feasible, and well tolerated in spite of the local socio-economical conditions.

Response to melphalan in up-front investigational window therapy for patients with metastatic Ewing's family tumours.

The aim of the study was to determine the activity and toxicity of melphalan as a single agent given in up-front therapy for patients with newly-diagnosed Ewing's family tumours with bone/bone marrow metastases. Nineteen patients were enrolled from 2001 to 2004. The treatment consisted of up-front therapy with melphalan (two courses of 50 mg/m2, 3 weeks apart). The overall rate of response to melphalan (complete response+partial response, according to the RECIST criteria) was 78%. Transient grade 3-4 neutropenia, thrombocytopenia and anaemia were recorded in 97%, 81% and 28% of melphalan courses, respectively. No other relevant toxicities were recorded. Melphalan proved to be active in up-front treatment at non-myeloablative doses, and its toxicity was predictable and manageable. The schedule adopted did not interfere with any further intensive chemotherapy or myeloablative treatment in the majority of cases.

Stage 4 neuroblastoma: sequential hemi-body irradiation or high-dose chemotherapy plus autologous haemopoietic stem cell transplantation to consolidate primary treatment.

The aim of the present study was to evaluate the effectiveness of two consecutive nonrandomised treatment programs applied between 1989 and 1999 at the Istituto Nazionale Tumori of Milan in an unselected cohort of 59 children over the age of one with stage 4 neuroblastoma. Both treatment programs consisted of two phases, the induction of the remission phase and the consolidation phase. The induction of the remission phase consisted of intensive chemotherapy, and remained the same throughout the study period. The consolidation phase consisted of sequential hemi-body irradiation (HBI) (10 Gy per session, 6 weeks apart) in the first period (1988-June 1994) and sequential high-dose cyclophosphamide, etoposide, mitoxantrone+L-PAM and autologous haemopoietic stem cell transplantation in the second (July 1994-1999). Intention-to-treat analysis revealed a significantly better outcome for patients treated with the second program, the 5-year event-free survival probability being 0.12 for program 1 and 0.31 for program 2 (P=0.03). This finding led us to conclude that sequential HBI is useless as consolidation treatment. The high-dose chemotherapy adopted in the second program enabled a proportion of patients to obtain long-term survival but, since the clinical results remain unsatisfactory, new treatment strategies are warranted.

Treatment of childhood Wilms' tumor without radiotherapy in Nicaragua.

BACKGROUND: Recent trends in therapeutic strategies for Wilms' tumor are based on an attempt to reduce or omit radiotherapy (RT) in a sizable fraction of patients. We report here the clinical and histological features as well as the results obtained in 37 children (23 males, 14 females; median age at diagnosis 3 years, range 0.8-8 years) diagnosed between 1991 and 1996, and treated with chemotherapy (CT) and surgery at La Mascota Hospital, Managua, Nicaragua. PATIENTS AND METHODS: Patients were grouped as follows: those who underwent surgery at diagnosis (group A, n = 4), patients who received preoperative CT because of large tumor size (group B, n = 27), lung metastases (n = 5) or bilateral disease (n = 1) (group C, n = 6). Treatment consisted of vincristine (VCR) and actinomycin-D (ACTD) for 24 weeks in group A, and of VCR, ACTD and adriamycin for 68 weeks in groups B and C. Histology was classified as favorable in 30 patients (81%), unfavorable in six patients (all of group B) and unknown in one. RESULTS: With a median follow-up time of 6.4 years the event-free survival for the whole group was 80.1%+/-6.8 (SE). No event occurred beyond 5 years of diagnosis. CONCLUSIONS: These results suggest that RT does not appear necessary for the majority of patients, and that an excellent surgical approach associated with an intensive CT schedule can control the disease, even in the absence of adequate information on the intra-abdominal tumor extent.

Undifferentiated nasopharyngeal carcinoma in children and adolescents: comparison between staging systems.

BACKGROUND: New criteria for classifying nasopharyngeal carcinoma were defined in the 5th edition of the American Joint Committee on Cancer (AJCC) staging manual. We investigated the clinical implications of the new system by comparing it with the 4th edition in a cohort of pediatric undifferentiated nasopharyngeal carcinoma (UNPC). PATIENTS AND METHODS: We retrospectively restaged 54 patients younger than 17 years who had biopsy-proven UNPC, treated between 1965 and 1999 in a single institution. RESULTS: Using the 5th edition an overall downstaging of the population according to T status, N status, and stage grouping was evident along with a better correlation with likelihood of survival. The comparison between local and advanced disease according to T stage (T1+T2 vs. T3+T4) became highly significant in the new system (P = 0.0011 vs. P = 0.067 in the 4th edition). CONCLUSIONS: As far as prognostic categories are concerned, the 5th edition of the AJCC staging manual appears to be an improvement over the previous classification, even though for pediatric patients a uniform distribution among stages cannot be observed because most children present with advanced disease. The overall downstaging should be taken into consideration for the stratification of patients in future trials.

Effects of recombinant human granulocyte-macrophage colony-stimulating factor in an intensive treatment program for children with Ewing's sarcoma.

BACKGROUND AND OBJECTIVES: A treatment program including polychemotherapy at progressively escalating doses and sequential hemi-body irradiation (HBI) was adopted between 1987-1994 at our Pediatric Unit for high risk Ewing's sarcoma. Granulocyte-macrophage colony-stimulating factor (GM-CSF) was added to the treatment program in a phase II study fashion to evaluate, in a pediatric setting, its tolerability, as well as its impact on drug dose escalation and on the need for supportive care. DESIGN AND METHODS: The study was open-label and sequential; GM-CSF administration (5 microg/Kg s.c./d x10) was planned after each chemotherapy cycle and after each HBI session in 18 consecutive patients (group A). Thirty-eight additional patients (group B) were treated by the same therapeutic program, without GM-CSF. In 12 patients (6 in each group) long-term bone marrow cultures (LTBMC) were performed to evaluate the myeloproliferative potential throughout the chemotherapeutic program. RESULTS: Seven of 18 (39%) patients experienced side effects from GM-CSF; 3/7 discontinued GM-CSF due to anaphylactic symptoms. The degree of neutropenia, as well as the frequency of infectious episodes and the need for supportive care were significantly lower in group A than in group B. Iatrogenic thrombocytopenia, and the possibility of performing drug-dose escalation were similar in the two groups. The 5-year event-free survival probabilities for group A and B were similar. LTBMC showed that the chemotherapy-related depletion of myeloid precursors could be more pronounced in patients receiving GM-CSF cyclically. INTERPRETATION AND CONCLUSIONS: In this series, GM-CSF was shown to be effective on iatrogenic neutropenia and related complications, with no impact on thrombopoiesis, drug dose escalation and outcome.

Childhood malignant ovarian germ cell tumors: a monoinstitutional experience.

OBJECTIVES: We reviewed our 23-year monoinstitutional exprience with childhood malignant ovarian germ cell tumors (MOGCT), with respect to survival and iatrogenic sequelae. METHODS: Twenty-nine patients (median age 12 years) with newly diagnosed MOGCT were treated: all girls but 2 underwent surgery as initial treatment. There were 9 pure dysgerminomas and 20 nondysgerminoma tumors (5 immature teratomas, 4 yolk sac tumors, and 11 mixed histology tumors). According to the FIGO classification, 9 girls were classified as stage I, 4 as II, 11 as III, and 3 as IV, and 2 were not evaluable because they were submitted to primary chemotherapy. Twenty-four received chemotherapy with VAC, PVB, or PEB regimens, according to the ongoing protocols through the years. Three stage I girls did not receive adjuvant chemotherapy because of their histology (2 dysgerminomas, 1 immature teratoma) and stage. In the early years, postoperative radiotherapy was given alone in advanced dysgerminoma stages. RESULTS: Five patients died of their disease: 2 dysgerminomas (stage IIIc and IV) and 3 nondysgerminomas (2 stage II and 1 stage IIIc). OS and EFS rates at a median of 112 months were 81.8%. Among 24 survivors, 4 experienced iatrogenic amenorrhea because of radiotherapy and/or bilateral oophorectomy. CONCLUSIONS: MOGCT are highly chemosensitive and curable, with preservation of reproductive function. The management of recurrent disease remains an open issue.

Refinement within single yeast artificial chromosome clones of a minimal region commonly deleted on the short arm of chromosome 7 in Wilms tumours.

Cytogenetic and molecular data indicate an involvement of genes mapped to the proximal portion of the short arm of chromosome 7 (7p) in Wilms tumours (WTs). We have analysed 38 WTs using a panel of eight microsatellite markers mapped to proximal 7p. Loss of heterozygosity (LOH) in tumour, compared with matched constitutional DNA, was identified in eight cases. To define better the minimal region commonly deleted in these tumours, they were analysed with nine additional markers, mapped within the region of interest. One tumour (case 30) showed LOH for only one marker (D7S510), while maintaining heterozygosity for the two immediately flanking loci (D7S555 and D7S668). This result was confirmed by fluorescence in situ hybridisation analysis, which showed that in the majority (65%) of nuclei from tumour 30 hybridising with a bacterial artificial chromosome clone containing the D7S510 locus, only one signal was visible. Noticeably, both markers defining the limits of the observed deleted region are simultaneously present within two distinct overlapping yeast artificial chromosome (YAC) clones mapped to chromosome bands 7p13-p14. This suggests that the maximum length of the missing DNA fragment was approximately 1.3 Mb, corresponding to the length of the smaller of the two YAC clones. In all other cases that showed LOH, the deletion encompassed the 7p13-p14 region. For this reason, we speculate that the identified interval contains a gene whose inactivation is important for the development of at least a fraction of WTs.

Management of medulloblastoma and ependymoma in infants: a single-institution long-term retrospective report.

To reduce the sequelae from CNS irradiation (RT), 16 children younger than 3 years with medulloblastoma-PNET (13 cases) and ependymoma (3 cases) were treated between 1987-1993 according to different postsurgical chemotherapy (CT) programs. None of these patients presented with metastases. Eleven patients were rendered disease-free by surgery, while 5 had residual tumor. Adjuvant therapy depended on patients' age, postsurgical status and parents' consent to radiotherapy (RT). Nine of the 16 infants remained alive in continuous complete remission from the first neoplasm (median follow-up 7 years). Three of them had been treated with CT alone and 6 with combined CT + RT (posterior fossa 4, whole CNS 2). Seven patients relapsed a median of 13 months after diagnosis, and all 7 of them died of their disease. Despite the omission of RT in 6 of the 16 patients and administration of only focal RT in 8 of the 16, the outcome of this series was satisfactory. Local failure (in 5/7 patients) was the major problem, despite the high dose of RT used in 2 of these 5. In 4 of 6 evaluable children school performance was satisfactory. One child in whom the entire CNS was irradiated developed glioblastoma multiforme 120 months after the first diagnosis of medulloblastoma.

Alveolar soft part sarcoma in children and adolescents: A report from the Soft-Tissue Sarcoma Italian Cooperative Group.

BACKGROUND: Alveolar soft part sarcoma (ASPS) is a rare malignant tumor and little is known about its clinical features and management. We report on a series of 19 pediatric patients managed over 20 years. PATIENTS AND METHODS: Primary conservative surgery was performed in all patients and was radical in nine, non-radical in three; seven patients underwent biopsy alone (3 unresectable tumors, 4 metastatic disease). In two cases radical surgery was performed after primary chemotherapy. Radiotherapy was delivered to 8 patients, chemotherapy to 15. RESULTS: After a median follow-up of 74 months, the five-year survival was 80% for the whole series, 91% for patients with localized disease, 100% for patients with tumor < or = 5 cm, and 31% for those > 5 cm; 16 of 19 patients were alive (12 of 12 with grossly-resected tumor in first continuous remission). Chemotherapy achieved two partial remission among seven evaluable patients. CONCLUSIONS: Pediatric ASPS has a more favorable prognosis than its adult counterpart. In this series, tumor size correlates with metastatic disease at onset and is the major factor influencing survival. Surgery is the mainstay of therapy. The effectiveness of adjuvant therapy remains to be established, though radiotherapy may be advisable in cases of inadequate surgery.

Malignant peripheral nerve sheath tumors in children: a single-institution twenty-year experience.

A retrospective series of pediatric patients with localized malignant peripheral nerve sheath tumors (MPNST) treated during a 20-year period at one institution is reported. Between 1976 and 1996, 24 consecutive children were treated by a multimodality approach. Conservative surgery was the treatment of choice: primary radical surgery was performed in 10. Postoperative radiotherapy was administered in 12 and adjuvant chemotherapy in 19. Eight patients were alive without evidence of disease, six in first complete remission and two in second complete remission, after a median follow-up of 230 months. The 10-year event-free survival (EFS) and survival were 29% and 41%, respectively. Survival was 80% for the patients who underwent radical surgery, and 14% for the others; 71% for patients with tumors smaller than 5 cm, and 29% for those with tumors 5 cm or larger. Local recurrence was the major cause for treatment failure (13 of 17; 76%); the rate of local relapse was 33% v 75% in patients who either received or did not receive radiotherapy. Complete surgical excision remains the most effective treatment for MPNST and represents the main prognostic factor along with tumor size. Radiotherapy seems to play a role in achieving local control, whereas the role of chemotherapy is uncertain.

Childhood liposarcoma: a single-institutional twenty-year experience.

A retrospective observational study was performed on a series of 12 consecutive pediatric patients treated over a 20-year period at the Istituto Nazionale Tumori, Milano. Conservative surgery was the treatment of choice in all patients; radical excision was obtained at diagnosis in 9 cases and after primary chemotherapy in 1 case. Five patients were subjected to surgery alone, and one to postoperative radiotherapy. After a median follow-up of 11 years (range 1-20), all the patients were alive without evidence of disease, 11 in first complete remission, and 1 after local relapse. In agreement with other reports, the authors underline the unquestionable pivotal role of radical surgery in the treatment of liposarcoma. The high proportion of resectable tumors accounts for the excellent survival of the patients in this study. The role of both adjuvant chemotherapy and radiotherapy is uncertain and awaits multicentric cooperative prospective studies.

Prognostic value of clinicopathologic characteristics including neuroectodermal differentiation in osseous Ewing's sarcoma family of tumors in children.

AIMS AND BACKGROUND: The aim of the present study was to determine the relationship between clinico-pathologic parameters, including neuroectodermal differentiation, and their impact on survival in a series of pediatric patients with osseous tumors of the Ewing's sarcoma family admitted to the Pediatric Department of the Istituto Nazionale Tumori of Milan. METHODS: Seventy-three patients were enrolled. The variables analyzed were sex, age, site of primary tumor, serum lactate dehydrogenase (LDH) level at diagnosis, involvement of periosseous soft tissues by primary tumor, presence of metastatic disease, status of disease after the treatment plan, as well as the presence of mitoses, morphologic and immunocytochemical neural markers, and neuroendocrine markers in the primary tumor. RESULTS: Neural and neuroendocrine markers were not significantly associated with any of the other parameters. In the univariate analysis, significant risk factors related to unfavorable outcome were elevated LDH, metastatic disease, lack of complete remission after treatment, presence of mitoses and of morphological neural markers; immunocytochemical neural and neuroendocrine markers lacked prognostic value. In the multivariate analysis, only LDH levels and the status of disease following the treatment were retained. CONCLUSIONS: LDH level at diagnosis might be a useful marker to identify different risk levels; neuroectodermal differentiation might have no clear-cut impact on the clinical management of osseous Ewing's sarcoma family of tumors.

Cytogenetic and molecular characterization of T-cell acute lymphoblastic leukemia as a second tumor after anaplastic large-cell lymphoma in a boy.

We report a case of acute T-cell lymphoblastic leukemia which developed in a boy 8.5 years after successful treatment for anaplastic large-cell lymphoma. Cytogenetic and molecular characterizations of the second tumor were performed. The cytogenetic investigation revealed a complex pattern of karyotypic alterations, including double minutes, ring chromosomes, and a duplication of the p21-32 region of chromosome 1. The microsatellite DNA analysis excluded rearrangement or deletion of the TAL1 gene in the tumor cells; rearrangements of the MLL gene were excluded by Southern blot analysis. To the best of our knowledge, this is the first report of T-cell lymphoblastic leukemia arising after treatment of CD 30+ anaplastic large-cell lymphoma. The different T-cell receptor rearrangement evidenced in the two tumors indicates that this second malignancy most likely emerged de novo, but was plausibly related to the previous radiation and chemotherapy.

Molecular analysis of 1p32 genetic involvement in pediatric T-cell non-Hodgkin's lymphoma.

BACKGROUND AND OBJECTIVE: T-cell acute lymphoblastic leukemia (T-ALL) and lymphoblastic T-cell non-Hodgkin's lymphoma (T-NHL) are closely related disorders, and distinguishing between the two may be difficult. Cytogenetic investigations of large NHL series reported different recurring chromosomal alterations. Among these, aberrations of chromosome 1p seem to be associated with T-cell differentiation, the region most frequently involved in breakpoints being band 1p32-36. Deletions and translocations involving the same chromosomal region are frequently observed in T-ALL, in which one of the most common genetic changes is the breakage of the TAL1 gene, mapped to the 1p32 chromosomal region. The objective of this study was to assess the possibility of TAL1 involvement also in T-NHL. DESIGN AND METHODS: A series of 17 pediatric T-NHL patients was molecularly characterized by microsatellite markers analysis and by TAL1 gene microdeletions. RESULTS: TAL1 gene rearrangement was found in one case, while loss of heterozygosity (LOH) and microsatellite instability (MI) was identified in another case. INTERPRETATION AND CONCLUSIONS: Overall our findings indicate that, differently from T-ALL, neither TAL1 gene involvement nor LOH or MI at 1p32 appear particularly relevant in the oncogenic process of T-NHL transformation.

Synovial sarcoma: report of a series of 25 consecutive children from a single institution.

BACKGROUND: The role of postoperative radiotherapy and adjuvant chemotherapy in the treatment of synovial sarcoma remains to be determined. PROCEDURE: Twenty-five children were treated during a 23-year period with a multimodality approach. All of them had resection of the primary tumor (three amputations), followed by surgical retreatment in eight. Postoperative radiotherapy was delivered to 16 patients and adjuvant chemotherapy was given to 22. RESULTS: At the time of the report, 19 patients were alive and without evidence of disease. Six developed distant metastases (one associated with local recurrence); five of them died of their disease and one was alive in complete remission at 4 years from relapse. With a median follow-up of 9 years (range 2-23), the survival and the event-free survival at 5 years were 80% (SE 8.2) and 74% (SE 9.2), respectively. All relapsing patients had been classified as T2B. CONCLUSIONS: Multimodality treatment yielded satisfying survival results using limb-preserving surgery in most cases. Tumor size > 5 cm and invasiveness, which defined stage T2B, were the most important predictors of poor outcome. Evaluation of the role of adjuvant chemotherapy and radiotherapy awaits prospective studies, even if T2B patients, as well as children having nonradical surgery, seem worth managing by adjuvant treatments.

North-South twinning in paediatric haemato-oncology: the La Mascota programme, Nicaragua.

We describe the La Mascota twinning programme between La Mascota paediatric hospital in Managua, Nicaragua, and hospitals in Monza and Milan, Italy, and Bellinzona, Switzerland. The programme was based on the belief that an attempt to reduce the gap in mortality from cancer in childhood between developed and less developed countries should become an integral part of the care and research activity of a haemato-oncological department of a developed country and not simply an exercise in solidarity. This programme for acute lymphoblastic leukaemia shows that intellectual, organisational, and financial resources can be generated by a twinning programme. What is vital for such programmes is a long-term commitment to a comprehensive and holistic strategy that incorporates supply of drugs, training and supervision of health professionals, and the care of the children and of their parents.

Retrospective analysis of ploidy in primary osseous and extraosseous Ewing family tumors in children.

AIMS: To retrospectively study the DNA content in a series of childhood Ewing Family Tumors (EFT), and to investigate its prognostic value. METHODS: The study was performed on a series of 27 EFTs (osseous Ewing's sarcoma, 18 cases; extraosseous Ewing's sarcoma, 2; peripheral neuroepithelioma, 4; Askin Rosai tumors, 3). Ploidy was investigated using both flow cytometry (FCM) and image cytometry (ICM) on tumor cell suspensions from formalin-fixed paraffin-embedded specimens or fresh frozen tissue obtained from the primary tumor at diagnosis. RESULTS: Ploidy was evaluable by FCM in all cases, and by ICM in 23/27. When fresh frozen tissue and paraffin-embedded samples from the same tumor were available for analysis, they yielded equal results. The rate of agreement between FCM and ICM was 82%. The majority of cases were diploid, and in the present series aneuploidy seemed to be associated with a poor outcome. CONCLUSIONS: These results suggest that aneuploidy could be an indicator of a bad prognosis in EFT; however, the small number of cases precludes any conclusion of statistical value. Larger retrospective studies on ploidy using archival material could be performed and their reliability is supported by the concordance of results from fresh and formalin-fixed tissue.

No evidence of WT1 involvement in a Burkitt's lymphoma in a patient with Denys-Drash syndrome.

BACKGROUND: We previously reported the case of a patient affected with Denys-Drash syndrome (DDS), who developed disseminated EBV-related Burkitt's lymphoma (BL) after kidney transplantation. Here, we describe the molecular characterisation of the WT1 gene in the constitutional and tumour DNA of this patient. PATIENTS AND METHODS: WT1 exons 2 to 10 were sequenced in constitutional and tumour DNAs. By Southern blotting the latter was also investigated for the presence of gene rearrangements. Gene expression analysis in tumour cells was performed by reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: A germline missense mutation affecting one of the zinc finger domains of the gene, and previously reported in other DDS cases, was observed. No alterations of the constitutionally wild-type WT1 allele and no expression of the gene were observed in BL cells. A small group of BLs from other paediatric patients showed a variable expression of WT1. CONCLUSIONS: Our findings indicate that WT1 is unlikely to be involved in the onset of BL in our case. However, a possible role of the gene in at least a subset of these lymphoproliferative diseases may be suggested.