Omission of doxorubicin from the treatment of stage II-III, intermediate-risk Wilms' tumour (SIOP WT 2001): an open-label, non-inferiority, randomised controlled trial.

BACKGROUND: Before this study started, the standard postoperative chemotherapy regimen for stage II-III Wilms' tumour pretreated with chemotherapy was to include doxorubicin. However, avoidance of doxorubicin-related cardiotoxicity effects is important to improve long-term outcomes for childhood cancers that have excellent prognosis. We aimed to assess whether doxorubicin can be omitted safely from chemotherapy for stage II-III, histological intermediate-risk Wilms' tumour when a newly defined high-risk blastemal subtype was excluded from randomisation. METHODS: For this international, multicentre, open-label, non-inferiority, phase 3, randomised SIOP WT 2001 trial, we recruited children aged 6 months to 18 years at the time of diagnosis of a primary renal tumour from 251 hospitals in 26 countries who had received 4 weeks of preoperative chemotherapy with vincristine and actinomycin D. Children with stage II-III intermediate-risk Wilms' tumours assessed after delayed nephrectomy were randomly assigned (1:1) by a minimisation technique to receive vincristine 1·5 mg/m(2) at weeks 1-8, 11, 12, 14, 15, 17, 18, 20, 21, 23, 24, 26, and 27, plus actinomycin D 45 µg/kg every 3 weeks from week 2, either with five doses of doxorubicin 50 mg/m(2) given every 6 weeks from week 2 (standard treatment) or without doxorubicin (experimental treatment). The primary endpoint was non-inferiority of event-free survival at 2 years, analysed by intention to treat and a margin of 10%. Assessment of safety and adverse events included systematic monitoring of hepatic toxicity and cardiotoxicity. This trial is registered with EudraCT, number 2007-004591-39, and is closed to new participants. FINDINGS: Between Nov 1, 2001, and Dec 16, 2009, we recruited 583 patients, 341 with stage II and 242 with stage III tumours, and randomly assigned 291 children to treatment including doxorubicin, and 292 children to treatment excluding doxorubicin. Median follow-up was 60·8 months (IQR 40·8-79·8). 2 year event-free survival was 92·6% (95% CI 89·6-95·7) for treatment including doxorubicin and 88·2% (84·5-92·1) for treatment excluding doxorubicin, a difference of 4·4% (95% CI 0·4-9·3) that did not exceed the predefined 10% margin. 5 year overall survival was 96·5% (94·3-98·8) for treatment including doxorubicin and 95·8% (93·3-98·4) for treatment excluding doxorubicin. Four children died from a treatment-related toxic effect; one (<1%) of 291 receiving treatment including doxorubicin died of sepsis, three (1%) of 292 receiving treatment excluding doxorubicin died of varicella, metabolic seizure, and sepsis during treatment for relapse. 17 patients (3%) had hepatic veno-occlusive disease. Cardiotoxic effects were reported in 15 (5%) of 291 children receiving treatment including doxorubicin. 12 children receiving treatment including doxorubicin, and ten children receiving treatment excluding doxorubicin, died, with the remaining deaths from tumour recurrence. INTERPRETATION: Doxorubicin does not need to be included in treatment of stage II-III intermediate risk Wilms' tumour when the histological response to preoperative chemotherapy is incorporated into the risk stratification. FUNDING: See Acknowledgments for funders.

Multiple mechanisms of MYCN dysregulation in Wilms tumour.

Genomic gain of the proto-oncogene transcription factor gene MYCN is associated with poor prognosis in several childhood cancers. Here we present a comprehensive copy number analysis of MYCN in Wilms tumour (WT), demonstrating that gain of this gene is associated with anaplasia and with poorer relapse-free and overall survival, independent of histology. Using whole exome and gene-specific sequencing, together with methylation and expression profiling, we show that MYCN is targeted by other mechanisms, including a recurrent somatic mutation, P44L, and specific DNA hypomethylation events associated with MYCN overexpression in tumours with high risk histologies. We describe parallel evolution of genomic copy number gain and point mutation of MYCN in the contralateral tumours of a remarkable bilateral case in which independent contralateral mutations of TP53 also evolve over time. We report a second bilateral case in which MYCN gain is a germline aberration. Our results suggest a significant role for MYCN dysregulation in the molecular biology of Wilms tumour. We conclude that MYCN gain is prognostically significant, and suggest that the novel P44L somatic variant is likely to be an activating mutation.

Nephron sparing surgery (NSS) for unilateral wilms tumor (UWT): the SIOP 2001 experience.

BACKGROUND: Total nephrectomy (TN) remains the standard treatment of unilateral Wilms tumors (uWT). The SIOP WT-2001 protocol allowed Nephron Sparing Surgery (NSS) for polar or peripherally non-infiltrating tumors. AIM: Inventory of the current SIOP NSS-experience. PROCEDURES: 2,800 patients with a unilateral, localized or metastatic and an unequivocal surgical technique recorded were included. All had neo-adjuvant chemotherapy and delayed surgery. In 91 (3%) NSS was performed and in 2709 TN. Data was retrieved from the SIOP WT 2001 database. RESULTS: NSS group contained 65% stage I tumours and the TN group 48%. Tumor volume (at diagnosis and surgery) was significantly smaller in the NSS group. Within stage III, after NSS, 7/12 (58%) had positive margins (M +), 5 with tumor negative lymph nodes (LN-). After TN, 355/712 (55%) had M + , 182 were LN-. Treatment of M+ in the NSS group resulted in two conversions to TN (one combined with radiotherapy), three patients had radiotherapy only and in two patients local therapy, if given, was not recorded. After NSS, four recurrences occurred. For localized disease the 5-year overall (OS) and event free survival (EFS) in NSS group was 100 and 94.8 (95% CI:89.9-99.9), respectively, while OS and EFS in the TN group were 94.4 (95% CI: 93.2-95.5, log-rank test P = 0.06) and 86.5 (95% CI:85.0-88.1, log-rank test P = 0.06), respectively. CONCLUSIONS: NSS was only performed in 3% of patients with uWT. Despite excellent survival with few relapses, the gain of nephrons needs to be weighed against the risk to induce stage III with intensified therapy.

Toxicity of upfront ¹³¹I-metaiodobenzylguanidine (¹³¹I-MIBG) therapy in newly diagnosed neuroblastoma patients: a retrospective analysis.

PURPOSE: In the treatment of patients with high-risk neuroblastoma, different doses of (131)I-metaiodobenzylguanidine ((131)I-MIBG) are administered at different time points during treatment. Toxicity, mainly haematological (thrombocytopenia), from (131)I-MIBG therapy is known to occur in extensively chemotherapy pretreated neuroblastoma patients. Up to now, acute toxicity from (131)I-MIBG as initial treatment has never been studied in a large cohort. The aim of this retrospective study was to document acute toxicity related to upfront (131)I-MIBG. METHODS: All neuroblastoma patients (stages 1-4 and 4S) treated upfront with (131)I-MIBG at the Emma Children's Hospital, Academic Medical Centre (1992 - 2008) were included in this retrospective analysis. The acute toxicity (during therapy) and short-term toxicity (1st month following therapy) of the first two (131)I-MIBG therapies were studied. RESULTS: Of 66 patients (34 boys, 32 girls; median age 2.2 years, range 0.1 - 9.4 years), 49 had stage 4 disease, 5 stage 4S, 6 stage 3, 1 stage 2 and 5 stage 1. The median first dose was 441 MBq/kg (range 157 - 804 MBq/kg). The median second dose was 328 MBq/kg (range 113 - 727 MBq/kg). The most frequently observed symptoms were nausea and vomiting (21 %, maximum grade II). The main toxicity was grade IV haematological, occurring only in stage 4 patients, after the first and second (131)I-MIBG therapies: anaemia (5 % and 4 %, respectively), leucocytopenia (3 % and 4 %) and thrombocytopenia (2 % and 4 %). No stem cell rescue was needed. CONCLUSION: The main acute toxicity observed was haematological followed by nausea and vomiting. One patient developed posterior reversible encephalopathy syndrome during (131)I-MIBG therapy, possibly related to (131)I-MIBG. We consider (131)I-MIBG therapy to be a safe treatment modality.

The role of 131I-metaiodobenzylguanidine (MIBG) therapy in unresectable and compromising localised neuroblastoma.

PURPOSE: In patients with localised neuroblastoma without adverse genetic aberrations, observational treatment is justified. Therapy is required when organ or respiratory functions have become compromised. As the outcome is good, side effects of treatment should be prevented. The aim of this retrospective study was to evaluate response and outcome in patients treated with (131)I-metaiodobenzylguanidine (MIBG) for unresectable localised neuroblastoma, with compromised organ functions. METHODS: Patients with localised neuroblastoma [median age 1.6 years (0-5.5 years)] diagnosed between 1989 and 2008 were included in this retrospective study (n = 21). Primary tumours were unresectable and there was a compromised organ or respiratory function. Diagnosis and staging were performed according to the International Neuroblastoma Staging System. Fixed doses of (131)I-MIBG therapy (50-200 mCi) were given. The median number of infusions was two (range one to seven). Response was graded according to the International Neuroblastoma Response Criteria. RESULTS: Of the 21 patients, 14 did not need any chemotherapy. Patients were treated with (131)I-MIBG therapy and, in most cases, with additional surgery and/or chemotherapy. Sixteen achieved complete response (CR), three very good partial response (VGPR), one partial response (PR) and one progressive disease (PD). Two patients died of PD after having achieved CR initially and due to surgical complications a few months after resection. Ten-year overall survival and event-free survival were 90.5 %. The median follow-up was 8.5 years (range 0.4-19.6 years). CONCLUSION: (131)I-MIBG therapy is an effective treatment modality for unresectable localised neuroblastoma with compromised organ functions. However, this was a small and heterogeneous cohort and further studies are needed.

Treatment of pulmonary metastases in children with stage IV nephroblastoma with risk-based use of pulmonary radiotherapy.

PURPOSE: The purpose of this study was to determine the outcome of children with nephroblastoma and pulmonary metastases (PM) treated according to International Society of Pediatric Oncology (SIOP) 93-01 recommendations using pulmonary radiotherapy (RT) in selected patients. PATIENTS AND METHODS: Patients (6 months to 18 years) were treated with preoperative chemotherapy consisting of 6 weeks of vincristine, dactinomycin, and epirubicin or doxorubicin. If pulmonary complete remission (CR) was not obtained, metastasectomy was considered. Patients in CR received three-drug postoperative chemotherapy, whereas patients not in CR were switched to a high-risk (HR) regimen with an assessment at week 11. If CR was not obtained, pulmonary RT was mandatory. RESULTS: Two hundred thirty-four of 1,770 patients had PM. Patients with PM were older (P < .001) and had larger tumor volumes compared with nonmetastatic patients (P < .001). Eighty-four percent of patients were in CR postoperatively, with 17% requiring metastasectomy. Thirty-five patients (16%) had multiple inoperable PM and required the HR protocol. Only 14% of patients received pulmonary RT during first-line treatment. For patients with PM, 5-year event-free survival rate was 73% (95% CI, 68% to 79%), and 5-year overall survival (OS) rate was 82% (95% CI, 77% to 88%). Five-year OS was similar for patients with local stage I and II disease (92% and 90%, respectively) but lower for patients with local stage III disease (68%; P < .001). Patients in CR after chemotherapy only and patients in CR after chemotherapy and metastasectomy had a better outcome than patients with multiple unresectable PM (5-year OS, 88%, 92%, and 48%, respectively; P < .001). CONCLUSION: Following the SIOP protocol, pulmonary RT can be omitted for a majority of patients with PM and results in a relatively good outcome.

Management of children with a Wilms tumor in Malawi, sub-Saharan Africa.

Wilms tumor has a survival rate of 85% to 90% in well-resourced countries. Malawi is a country in Sub-Saharan Africa with very limited resources. We evaluated the outcome of a treatment guideline including preoperative chemotherapy, supportive care, and strategies to enable parents to complete treatment. Between 2006 and 2011, 95 patients were initially diagnosed with a Wilms tumor; 11 were later excluded due to misdiagnosis. In 31% of patients, metastases were detected at presentation. Treatment outcomes in 8 patients with bilateral tumors and 3 patients who were referred after nephrectomy are analyzed separately. Treatment failed in 51% of 73 remaining patients. Reasons for failure were: 1) incomplete treatment (7%); 2) treatment-related deaths (15%); and 3) disease-related deaths (28%) with 11% unresectable tumors or metastases after preoperative chemotherapy and 17% relapse of disease. Projected survival is 46%. Challenges remain to improve survival for children with Wilms tumor in Malawi. Earlier diagnosis would reduce disease-related deaths as numbers of unresectable disease and relapse are high. Effective strategies, including social support, to enable parents to complete treatment need to be continued. Improved supportive care and nutritional support and possibly less intense preoperative chemotherapy are needed to reduce treatment-related deaths.

Characteristics and outcome of stage II and III non-anaplastic Wilms' tumour treated according to the SIOP trial and study 93-01.

PURPOSE: To determine the prognosis of children with stage II and III of low or intermediate risk histology (SIOP classification) in unilateral localised Wilms tumour (WT) after neoadjuvant chemotherapy according to the trial and study of the International Society of Paediatric Oncology, SIOP 93-01. PATIENTS AND METHODS: Patients with unilateral localised WT and stage II or III with low (LR) or intermediate risk (IR) histology between 6 months and 18 years of age, were selected from the total sample of patients registered in the SIOP 93-01 study between June 1993 and December 2001. All patients received 4 weeks of actinomycin-D/vincristine before surgery. Postoperative chemotherapy consisted of actinomycin-D, vincristine and epirubicin/doxorubicin for 27 weeks. Flank or whole abdomen irradiation was given for stage III. Event-free survival (EFS) and overall survival (OS) were analysed for various subgroups. RESULTS: Of 1476 registered patients 594 (40%) met the inclusion criteria for this analysis. Four hundred and two (67%) had stage II disease and 563 (95%) had intermediate risk histology. Median tumour volume was 439 ml at diagnosis and 163 ml after preoperative chemotherapy. With a median follow-up of 8 years, 5-year EFS was 90% (95% confidence interval [95% CI]: 87-92%) and OS 95% (95% CI: 93-97%). Patients with stage III, blastemal type histology and a large volume at surgery had a worse outcome. CONCLUSION: Treatment for stage II and III LR or IR WT is successful in a neoadjuvant setting as advised by the SIOP. Stage, tumour volume and blastemal type histology are the most important prognostic factors.

The efficacy and toxicity of SIOP preoperative chemotherapy in Malawian children with a Wilms tumour.

BACKGROUND: In Malawi, preoperative chemotherapy for Wilms tumour is a logical strategy, but detailed information on toxicity and efficacy in such a resource limited setting has been unavailable. PROCEDURE: Patients diagnosed with a unilateral Wilms tumour received preoperative chemotherapy-a two-drug 4-week regimen for localized disease and 6 weeks of a three-drug regimen for metastatic disease. Estimated maximum tumour diameter, decrease in tumour size, resectability, stage distribution and haematological toxicity during therapy were documented. RESULTS: At diagnosis, 28% of 72 patients had an estimated maximum tumour diameter of more than 25 cm; 29% of patients had metastases. Eight children (11%) died during preoperative chemotherapy. More than half (59%) of the patients developed moderate neutropenia (neutrophils <1.0 × 10(9) /L; CTC grade 3) and 27% severe neutropenia (CTC grade 4 neutrophils <0.5 × 10.9/L). Grade 4 neutropenia occurred significantly more frequently in children receiving the three-drug regimen compared to the two-drug regimen; 50% (10/20) versus 15% (6/40) (P = 0.004). Fifty-seven percent of all patients had CTC grade 4 anaemia (Hb < 6.5 g/dL) during treatment. Most tumours (92%, 56/61) showed a response to chemotherapy but 14% (8/58) remained unresectable. CONCLUSION: Preoperative chemotherapy for Wilms tumour causes considerable haematological toxicity and treatment-related mortality in malnourished Malawian children. A significant number of children have unresectable disease despite preoperative chemotherapy. To reduce treatment related mortality, consideration should be given to starting treatment with reduced doses in acutely malnourished patients.

The contribution of chest CT-scan at diagnosis in children with unilateral Wilms' tumour. Results of the SIOP 2001 study.

BACKGROUND: The SIOP 2001 nephroblastoma study hypothesised that patients with 'CT-only' pulmonary nodules would have the same outcome as patients with localised disease of same stage and histology. PATIENTS: Unilateral Wilms' tumour (WT) patients, who had chest CT scans at diagnosis showing any sized pulmonary nodules undetected on chest X-ray, between November 2001 and November 2009, were selected from the SIOP 2001 database. RESULTS: Among 2532 WT patients, 103 unilateral nephroblastoma patients with CT-only lung lesions were found. Thirty-seven patients received preoperative treatment according to the localised-disease protocol, and 66 according to the metastatic-disease protocol. The 3-year event-free survival (EFS) was 70% (95% CI: 55-89%) and 77% (95% CI: 66-89%), respectively. Corresponding 3-year overall survival (OS) was 89% (95% CI: 77-100%) and 85% (95% CI: 75-96%), respectively (p-value not significant). EFS and OS of all 2071 patients with true localised disease were 87% (95% CI: 86-89%) and 96% (95% CI: 94-97%), respectively. Patients with metastatic disease (n = 358) had 3-year EFS and OS estimates of 68% (95% CI: 63-74%) and 77% (95% CI: 72-82%), respectively. CONCLUSIONS: EFS and OS of patients with CT-only lung lesions were inferior to that of true localised-disease patients and superior to that of patients with metastatic disease. However, no significant difference was found in EFS and OS between CT-only patients treated for localised or metastatic disease. The clinician's preference to treat patients with CT-only pulmonary nodules as metastatic disease is not evidence-based. Chest CT at diagnosis does not improve outcome but presents paediatric oncologists with a difficult dilemma.

Management of adults with Wilms' tumor: recommendations based on international consensus.

Since Wilms' tumor occurs rarely in adults, there are no standard treatments available. Most adult patients will be diagnosed unexpectedly following nephrectomy for presumed renal cell carcinoma. Outcome for adults is inferior compared with children, although better results are reported when treated within pediatric trials. Multiple factors, including the unfamiliarity of adult oncologists and pathologists with Wilms' tumors, lack of standardized treatment and consequent delays in initiating the appropriate risk-adapted therapy, may contribute to the poor outcome. A standardized approach for the management of adult Wilms' tumors is proposed with the aim to limit treatment delay after surgery and encourage a uniform approach for this rare disease and thereby improve survival. These recommendations are based on discussions held with representatives of the renal tumor committees of the Society of Paediatric Oncology and Children's Oncology Group, and have been updated with a review of more recently published institutional and trial experience of adults treated on pediatric protocols. They provide a critical evaluation of the current evidence for the management of adult Wilms' tumors and propose details of how current pediatric therapeutic guidelines could be adapted for use in adults.

Nephroblastoma: does the decrease in tumor volume under preoperative chemotherapy predict the lymph nodes status at surgery?

BACKGROUND: Partial nephrectomy (NSS) for unilateral nephroblastoma may be beneficial, although in case of regional lymph node (LN) involvement, radiotherapy counteracts the functional benefit of NSS. The aim is to verify whether decrease of tumor volume under preoperative chemotherapy implies clearance of regional LN. PROCEDURE: SIOP 9301 (1993-2001) collected 1,450 localized nephroblastoma patients of whom 1,360 (93%) had sufficiently available data and were retrospectively reviewed. RESULTS: Histologic subtypes were classically distributed. Patients were divided in those with tumor positive LN (76, 5.5%) and those with tumor negative LN (1,284, 94.5%) at surgery. In the LN(+) group, the tumor volume changed from a median of 554 (318-772) to 192 (63-458) ml = 67% (27-88%) during preoperative ChT. In the LN(-) group-377 (200-612) to 130 (44-294) ml = 62% (28-83%) (NS). Increase of tumor volume was observed in 16% of patients with LN(+), and 11% of those with LN(-) (NS); ranges are interquartile. Initial tumor volume was significantly larger in the LN(+) patients (P = 0.00091) but not different (NS) at surgery; patients with initial tumor volume under 318 ml had the regional LN involved significantly less frequently (P = 0.00751). CONCLUSIONS: Change in tumor volume under preoperative chemotherapy is not a predictor for LN status at surgery, although larger initial volume is associated with a higher risk of LN invasion. The decrease of tumor volume is not a good criterion for the safety of NSS. The low rate of LN(+) (5.5%) indicates that this risk is low.

Long-term outcome of bilateral Wilms tumors (BWT).

BACKGROUND: Modern WT management consist of ample chemotherapy, nephron-sparing surgery, and, when indicated, radiotherapy. Survivors may develop renal failure or secondary tumors due to anticancer treatment. We analyzed long-term outcome (follow-up >5 years) after bilateral Wilms tumor (BWT) treatment with respect to survival, renal function, and secondary malignancies. METHODS: From 41 patients (23 females, 28 synchronous tumors) diagnosed with BWT between 1967 and 2007, 25 (18 females, 14 synchronous) with a follow-up >5 years could be included. Of this subgroup, median age at diagnosis was 1.64 years (range 0.27-5.35), and at maximum follow-up 14.99 years (range 5.40-33.99). Data were retrospectively collected and analyzed. RESULTS: One patient (4%) died 17.75 years after diagnosis, five (20%) had renal transplants: 3/5 after bilateral nephrectomy for Denys-Drash syndrome (DDS), and 2/5 for ESRD after an interval of 7 and 18 years, respectively. All transplanted patients remained in CR. Another three patients developed mild renal insufficiency (creatinine levels 1.3, 1.8, and 2.8 mg/100 ml, respectively; N = 0.5-1.2), combined with hypertension in 1; neither of them was transplanted. Sixteen (64%) had normal renal function and were in CR. Long-term renal function appeared significantly better after bilateral nephron sparing surgery (NSS) then after other surgical procedures (P < 0.0001). Seven secondary tumors were found in five (20%) patients, one of whom had a DDS. CONCLUSION: Long-term 10-year overall survival was 78%. There was significant morbidity (13/25, 52%), in terms of renal failure (8/25, 32%) including renal transplantation (5/25, 20%), and secondary tumors (5/25). These findings necessitate long-term follow-up beyond childhood. Future work should be directed at reducing the harmful effects of treatment, including the increased use of NSS.

Malignant rhabdoid tumours of the kidney (MRTKs), registered on recent SIOP protocols from 1993 to 2005: a report of the SIOP renal tumour study group.

BACKGROUND: Survival data of malignant rhabdoid tumour of the kidney (MRTK) registered in SIOP trials, advocating preoperative chemotherapy, are not available. AIM: To evaluate characteristics, response and survival of MRTK patients registered in recent SIOP protocols. METHODS: An evaluation of all MRTK patients treated from 1993 to 2005 (SIOP trials 93-01 and 2001) was performed. Data were obtained from study specific case record forms and entered centrally in a database. RESULTS: Hundred and seven patients were identified (57 male), with a median age at diagnosis of 13 months (interquartile range 6-27 months), and a median follow-up time of 60 months. Left and right kidneys were equally affected. Tumour stage distribution was stage I (6%), stage II (22%), stage III (43%), stage IV (22%) and stage V (3%). Stage IV patients included 17 with pulmonary metastasis (8 lung-only) and 12 with multiple organ metastases (bone, brain and liver). Primary surgery was the upfront treatment approach in 22/107 patients (21%), by which 19 patients reached a complete remission (CR). Median difference in tumour volume before and after preoperative chemotherapy was 69 ml (interquartile range: 4.5-158.0, P < 0.0001), indicating marked chemosensitivity. The 5-year event-free survival (EFS) of the total group was 22% (95% CI: 15-33) and overall survival 26% (95% CI: 18-37). Most events (86%) occurred within the first 2 years after diagnosis. Younger age at diagnosis was an important adverse prognostic factors for survival. In contrast, tumour volume at diagnosis, nor volume reduction was associated with outcome. CONCLUSION: MRTK has a poor outcome especially in young and advanced-stage disease patients. Neither tumour volume at diagnosis, nor pre-operative chemosensitivity are prognostic factors for survival.

From amino acid to glucosinolate biosynthesis: protein sequence changes in the evolution of methylthioalkylmalate synthase in Arabidopsis.

Methylthioalkylmalate synthase (MAM) catalyzes the committed step in the side chain elongation of Met, yielding important precursors for glucosinolate biosynthesis in Arabidopsis thaliana and other Brassicaceae species. MAM is believed to have evolved from isopropylmalate synthase (IPMS), an enzyme involved in Leu biosynthesis, based on phylogenetic analyses and an overlap of catalytic abilities. Here, we investigated the changes in protein structure that have occurred during the recruitment of IPMS from amino acid to glucosinolate metabolism. The major sequence difference between IPMS and MAM is the absence of 120 amino acids at the C-terminal end of MAM that constitute a regulatory domain for Leu-mediated feedback inhibition. Truncation of this domain in Arabidopsis IPMS2 results in loss of Leu feedback inhibition and quaternary structure, two features common to MAM enzymes, plus an 8.4-fold increase in the k(cat)/K(m) for a MAM substrate. Additional exchange of two amino acids in the active site resulted in a MAM-like enzyme that had little residual IPMS activity. Hence, combination of the loss of the regulatory domain and a few additional amino acid exchanges can explain the evolution of MAM from IPMS during its recruitment from primary to secondary metabolism.

Fanconi anemia gene mutations are not involved in sporadic Wilms tumor.

Bi-allelic germline mutations of the Fanconi anemia (FA) genes, PALB2/FANCN and BRCA2/FANCD1, have been reported in a few Wilms tumor (WT) patients with an atypical FA phenotype. Therefore, we screened a random cohort of 47 Dutch WT cases for germline mutations in these two FA-genes by DNA sequencing and Multiplex Ligation-dependent Probe Amplification (MLPA). Although several cases appeared to carry missense variants, no bi-allelic pathogenic mutations were identified, indicating that bi-allelic mutations in these FA-genes do not contribute significantly to the occurrence of WT.

Stromal and epithelial predominant Wilms tumours have an excellent outcome: the SIOP 93 01 experience.

BACKGROUND: Wilms tumour (WT) has various subtypes that are correlated with prognosis and require distinct therapy. Stromal predominant (SpWT) and epithelial WT (EpWT) have previously been associated with a good outcome. The current analysis describes the outcome and (tumour) characteristics of all patients with SpWT, EpWT, including highly differentiated epithelial type (HDET), treated according to the International Society of Pediatric Oncology (SIOP) 93-01 study. PROCEDURE: All children older than 6 months and below 18 years of age with localized or metastatic WT and intermediate risk (IR) histology or HDET treated with pre-operative chemotherapy were included in the present analysis. RESULTS: A total of 1,389 eligible patients had IR or HDET histology: 1% HDET, 4% EpWT, 10% SpWT, and 85% other IR. For EpWT/HDET, 93% had stage I/IIN-, 5-year EFS was 90.2% and overall survival of (OS) 98.4%, as compared to 84.0% and 92.5% in other IR histology (NS). Stage I EpWT/HDET had a significant better outcome than stage I of other IR. In SpWT 82% of cases had stage I/IIN-; 5-year EFS was 94.3% and OS 99.2%, significantly better compared to other IR histology. All patients with stage I are alive (2/149 relapses); 3/52 stage IIN-, 2/21 stage IIN+/III, and 6/12 stage IV patients relapsed (1 deceased per stage group). CONCLUSIONS: The good outcome for EpWT and SpWT generally is very good which may be related to low age and low stage in most cases. A reduction of treatment intensity and/or duration may be justified especially for low stage SpWT that has an EFS close to 100%.

Malignant tumours of the kidney: imaging strategy.

Primitive malignant renal tumours comprise 6% of all childhood cancers. Wilms tumour (WT) or nephroblastoma is the most frequent type accounting for more than 90%. Imaging alone cannot differentiate between these tumours with certainty but it plays an important role in screening, diagnostic workup, assessment of therapy response, preoperative evaluation and follow-up. The outcome of WT after therapy is excellent with an overall survival around 90%. In tumours such as those where the outcome is extremely good, focus can be shifted to a risk-based stratification to maintain excellent outcome in children with low risk tumours while improving quality of life and decreasing toxicity and costs. This review will discuss the imaging issues for WT from the European perspective and briefly discuss the characteristics of other malignant renal tumours occurring in children and new imaging techniques with potential in this matter.

Evaluation of late adverse events in long-term wilms' tumor survivors.

PURPOSE: To evaluate the prevalence and severity of adverse events (AEs) and treatment-related risk factors in long-term Wilms' tumor (WT) survivors, with special attention to radiotherapy. METHODS AND MATERIALS: The single-center study cohort consisted of 185 WT survivors treated between 1966 and 1996, who survived at least 5 years after diagnosis. All survivors were invited to a late-effects clinic for medical assessment of AEs. AEs were graded for severity in a standardized manner. Detailed radiotherapy data enabled us to calculate the equivalent dose in 2 Gy fractions (EQD(2)) to compare radiation doses in a uniform way. Risk factors were evaluated with multivariate logistic regression analysis. RESULTS: Medical follow-up was complete for 98% of survivors (median follow-up, 18.9 years; median attained age, 22.9 years); 123 survivors had 462 AEs, of which 392 had Grade 1 or 2 events. Radiotherapy to flank/abdomen increased the risk of any AE (OR, 1.08 Gy(-1) [CI, 1.04-1.13]). Furthermore, radiotherapy to flank/abdomen was associated with orthopedic events (OR, 1.09 Gy(-1) [CI, 1.05-1.13]) and second tumors (OR, 1.11 Gy(-1) [CI, 1.03-1.19]). Chest irradiation increased the risk of pulmonary events (OR, 1.14 Gy(-1) [CI, 1.06-1.21]). Both flank/abdominal and chest irradiation were associated with cardiovascular events (OR, 1.05 Gy(-1) [CI, 1.00-1.10], OR, 1.06 Gy(-1) [CI, 1.01-1.12]) and tissue hypoplasia (OR, 1.17 Gy(-1) [CI, 1.10-1.24], OR 1.10 Gy(-1) [CI, 1.03-1.18]). CONCLUSION: The majority of AEs, overall as well as in irradiated survivors, were mild to moderate. Nevertheless, the large amount of AEs emphasizes the importance of follow-up programs for WT survivors.

Treatment of relapsed Wilms tumors: lessons learned.

Treatment regimens for recurrent Wilms tumor (WT) are currently designed to include drugs that are not used during primary chemotherapy, using a risk-stratified approach. Therapy of recurrent disease depends on the nature of initial treatment, and of recognized prognostic indicators inherent in the primary tumor. Several highly effective chemotherapy regimens, including ifosfamide-carboplatin-etoposide, cyclophosphamide-etoposide and carboplatin-etoposide, are considered first treatment choice for recurrent disease. While intense-dose chemotherapy is uniformly accepted to treat high-risk recurrent WTs, the optimal therapy for standard-risk children has yet to be defined, owing to the small number of such patients and their relatively better prognosis compared with high-risk recurrences. Recurrent tumors among those defined as very-high risk are likely to develop chemoresistant disease, and novel therapeutic strategies will be necessary to cure these patients. Evidence on how to properly administer surgery and radiotherapy at relapse is more fragmentary. The authors have reviewed the available experiences concerning the treatment of recurrent WT, and have attempted to provide the most up-to-date recommendations regarding the optimal risk-based treatment for these patients.