[Wilms' tumour: A review of 15 years recent experience]. / Tumor de Wilms: revisión de nuestra experiencia en los últimos 15 años.

INTRODUCTION: Wilms' tumour is the most frequent renal tumour in children. Multi-modal treatment includes chemotherapy and surgery, with or without radiotherapy. The survival is excellent, with rates exceeding 90%. A review is presented on our experience over the last 15 years of treating Wilms' tumour in Hospital Niño Jesús, Madrid. PATIENTS AND METHODS: A retrospective study was conducted on 40 consecutive paediatric patients diagnosed with nephroblastoma between 2002 and 2016 in the Hospital Niño Jesús in Madrid. The clinical characteristics, diagnostic methods, treatment, and follow-up were analysed. RESULTS: Of the 40 patients, 23 were boys, with a median age at diagnosis of 2.5 years (range, 4 months-15 years). Three patients underwent initial nephrectomy, three received a fine needle aspiration biopsy, followed by chemotherapy, and 34 patients started pre-operative chemotherapy directly. The median follow-up of the patients was 6.75 years (range, 10 months - 13.92 years). Two patients died from disease progression. There were no treatment-related deaths. Overall survival and event-free survival at 5 years was 94.6±3.7% and 89.4±5%, respectively. CONCLUSION: Wilms' tumour treatment is a success of modern medicine, currently achieving a survival rate of 95% in our series.

Ataxia-telangiectasia and wilms tumor: reduced treatment but early relapse.

Ataxia-telangiectasia (A-T) is an autosomal recessive disease characterized by progressive cerebellar ataxia, oculocutaneous telangiectasia, immunodeficiency, a high incidence of lymphoreticular tumors, and an increased sensitivity to chemoradiotherapy-induced DNA damage. The appropriate cancer therapy remains unknown because of high toxicity rates with full-dose conventional protocols. We present a patient with A-T and nephroblastoma, who received an adapted treatment regimen. To our knowledge this is the second report on nephroblastoma in a patient with A-T but the first with confirmed premortem studies. Although the patient tolerated the chemotherapy regimen well, the patient relapsed and died a year after initial diagnosis.

Defining "poor mobilizer" in pediatric patients who need an autologous peripheral blood progenitor cell transplantation.

The definition of poor mobilizers is not clear in pediatric patients undergoing autologous peripheral blood hematopoietic progenitor cell (HPC) mobilization. Most studies conducted in children define those variables related to the collection of HPC after leukapheresis, but the information regarding exclusively the mobilization process is scarce. In our experience, most children (92.2%) reach the target CD34(+) cell dose for autologous peripheral blood progenitor cell transplantation if CD34(+) cell count was higher than 10/µL. No differences were observed between those with >20 CD34(+) cells/µL and 11-20 CD34(+) cells/µL. In this study, we analyzed the variables that influence CD34(+) cell count; we found that prior use of radiotherapy was the main variable related to poor mobilization. Patients diagnosed with Ewing sarcoma, treated with radiotherapy and mobilized with standard doses of granulocyte colony-stimulating factor (G-CSF) were also at a high risk of mobilization failure. In these patients, we should consider mobilization with high dose G-CSF and be prepared with new mobilization agents to avoid delay on their course of chemotherapy.

High-dose busulfan and melphalan as conditioning regimen for autologous peripheral blood progenitor cell transplantation in high-risk neuroblastoma patients.

The aim of this retrospective study was to analyze the outcome and identify risk factors associated with progression-free survival (PFS) in 36 children with high-risk neuroblastoma who underwent autologous peripheral blood progenitor cell (PBPC) transplantation between 1994 and 2010. The conditioning regimen used in all cases consisted of high-dose of busulfan and melphalan. Median age at transplantation was 3 years (range: 0.7-14 years). The median times to neutrophil and platelet engraftment were 11 days (range: 9.16 days) and 13 days (range: 9.33), respectively. Twenty-one patients developed nonhematologic toxicity: 15 patients had mucositis, 4 patients developed an engraftment syndrome, and there were 2 cases of liver toxicity. No toxic deaths were observed. There were 15 patients who relapsed. The median time to relapse was 6 months after the transplant (range: 3-13 months). With a median follow-up of 55 months (range: 4-180 months), the PFS was 57% ± 8.5% for the whole group. In multivariate analysis, age below 3 years (P < .005), complete remission (CR) pretransplantation (P < .07) and 1p germline status (P < .01) were variables associated with better outcomes. Patients who were or achieved early CR following transplantation (3 months posttransplantation) had a probability of PFS of 91% ± 6% as compared to patients who did not (PFS 9% ± 8%) (P < .0001). This retrospective study shows that high dose of busulfan and melphalan as conditioning regimen in children with high-risk neuroblastoma is associated with very low morbidity and no mortality in the authors' hands. Younger patients with no 1p deletions and in first CR at transplantation had the better outcome.