Long-term outcomes and patterns of relapse in patients with bilateral Wilms tumor or bilaterally predisposed unilateral Wilms tumor, a report from the COG AREN0534 study.

The objective of this study is to report the long-term timing and patterns of relapse for children enrolled in Children's Oncology Group AREN0534, a multicenter phase III clinical trial conducted from 2009 to 2015. Participants included children with bilateral Wilms tumor (BWT) or unilateral WT with genetic predisposition to develop BWT followed for up to 10 years. Smoothed hazard (risk) functions for event-free survival (EFS) were plotted so that the timing of events could be visualized, both overall and within pre-specified groups. Two hundred and twenty-two children (190 BWT and 32 unilateral WT with BWT predisposition) were followed for a median of 8.6 years. Fifty events were reported, of which 48 were relapse/progression. The overall 8-year EFS was 75% (95% confidence interval: 69%-83%). The highest risk for an EFS event was immediately after diagnosis with a declining rate over 2 years. A second peak of events was observed around 4 years after diagnosis, and a small number of events were reported until the end of the follow-up period. In subset analyses, later increases in risk were more commonly observed in patients with female sex, anaplastic histology, negative lymph nodes or margins, and favorable histology Wilms tumor patients with post-chemotherapy intermediate risk. Among relapses that occurred after 2 years, most were to the kidney. These patterns suggest that late events may be second primary tumors occurring more commonly in females, although more investigation is required. Clinicians may consider observation of patients with BWT beyond 4 years from diagnosis.

Wilms tumor characteristics, surgical management, outcomes, and chronic kidney disease in children with WAGR syndrome: A report from the International WAGR Syndrome Association survey.

INTRODUCTION: Children with WAGR (Wilms tumor, aniridia, genitourinary anomalies, and range of development delays) syndrome are predisposed to Wilms tumor (WT) and intrinsic kidney disease. Using the comprehensive International WAGR Syndrome Association (IWSA) survey of children with WAGR syndrome, we analyzed tumor characteristics, treatment and congenital risk factors, and kidney function in children with WAGR and WT. METHODS: Descriptive statistics were utilized including demographics, treatment strategies, and patient outcomes. Comparisons were made between patients with WAGR and WT to those with WAGR alone. A multivariable logistic regression was completed for risk of developing WT and to identify predictors of chronic kidney disease (CKD). RESULTS: Sixty-four of 145 children with WAGR developed WT (44.1%). Three relapsed and one died. CKD developed in five children with WAGR without WT (5/81, 6.2%), and in 34 with WAGR and WT (34/64, 28.3%). Children with WAGR and WT were younger (p = .017), and had a greater association with CKD than WAGR children without WT (p < .0001). Two children with WT required hemodialysis, and one underwent kidney transplantation. By univariate analysis, CKD at any stage was associated with complete nephrectomy for the WT surgery (p < .0001), chemotherapy duration greater than 12 months, and three-drug therapy. Upon multivariate analysis, prior nephrectomy was the only significant variable (p = .0002). CONCLUSIONS: Epidemiological analysis of children with WAGR demonstrated favorable oncologic outcomes, but high rate of early CKD in those who developed WT. Further study of the use of nephron-sparing surgery in children with WAGR and strategies to delay or treat early CKD are needed.

Bilateral Wilms tumor with anaplasia: A report from the Children's Oncology Group Study AREN0534.

INTRODUCTION: The purpose of this study is to examine the outcomes in children with anaplastic bilateral Wilms tumor (BWT) from study AREN0534 in order to define potential prognostic factors and areas to target in future clinical trials. METHODS: Demographic and clinical data from AREN0534 study patients with anaplasia (focal anaplasia [FA], or diffuse anaplasia [DA]) were compared. Event-free survival (EFS) and overall survival (OS) were reported using Kaplan-Meier estimation with 95% confidence bands, and differences in outcomes between FA and DA compared using log-rank tests. The impact of margin status was analyzed. RESULTS: Twenty-seven children who enrolled on AREN0534 had evidence of anaplasia (17 DA, 10 FA) in at least one kidney and were included in this analysis. Twenty-six (96%) had BWT. Nineteen percent had anaplastic histology in both kidneys (four of 17 DA, and one of 10 FA). Forty-six percent with BWT had bilateral nephron-sparing surgery (NSS); one child who went off protocol therapy, eventually required bilateral completion nephrectomies. Median follow-up for EFS and OS was 8.6 and 8.7 years from enrollment. Four- and 8-year EFS was 53% [95% confidence interval (CI): 34%-83%] for DA; 4-year EFS was 80% [95% CI: 59%-100%], and 8-year EFS 70% [95% CI: 47%-100%] for FA. Three out of 10 children with FA and eight out of 17 children with DA had events. EFS did not differ statistically by margin status (p = .79; HR = 0.88). Among the six children who died (five DA, one FA), all experienced prior relapse or progression within 18 months. CONCLUSION: Events in children with DA/FA in the setting of BWT occurred early. Caution should be taken about interpreting the impact of margin status outcomes in the context of contemporary multimodal therapy. Future targeted investigations in children with BWT and DA/FA are needed.

The varied spectrum of nephroblastomatosis, nephrogenic rests, and Wilms tumors: Review of current definitions and challenges of the field.

The diagnosis of multiple or diffuse renal lesions in a child is challenging by imaging and/or pathology. Optimal management requires distinguishing benign lesions such as nephrogenic rests from cancerous lesions such as Wilms tumor, but this is often difficult or impossible. This difficulty is compounded by the overlapping nature of our current radiologic and pathologic definitions of lesions along the spectrum of nephrogenic rests/nephroblastomatosis. We provide a review of these issues, as a collaborative effort between the Children's Oncology Group Renal Tumor Committee and International Society of Pediatric Oncology Renal Tumor Study Group. Our aim is to discuss current challenges in diagnosis and management of these renal lesions, encouraging future work toward consensus definitions for research and patient care.

Outcomes based on histopathologic response to preoperative chemotherapy in children with bilateral Wilms tumor: A prospective study (COG AREN0534).

BACKGROUND: An objective of the Children's Oncology Group AREN0534 Study was to improve the survival of patients with bilateral Wilms tumors (BWT) by using preoperative chemotherapy of limited duration and tailoring postoperative therapy based on histopathologic response. The authors report outcomes based on postoperative histopathologic responses. METHODS: Patients with BWT received treatment with vincristine, dactinomycin, and doxorubicin for 6 or 12 weeks followed by surgery. Postoperative therapy was prescribed based on the highest risk tumor according to the International Society of Pediatric Oncology classification and the Children's Oncology Group staging system. RESULTS: Analyses were performed on data from 180 evaluable children. The 4-year event-free survival (EFS) and overall survival (OS) rates were 81% (95% CI, 74%-87%) and 95% (95% CI, 91%-99%), respectively. Seven patients who had completely necrotic tumors had a 4-year EFS rate of 100%. Of 118 patients who had tumors with intermediate-risk histopathology, the 4-year EFS and OS rates were 82% (95% CI, 74%-90%) and 97% (95% CI, 94%-100%), respectively. Fourteen patients who had blastemal-type tumors had 4-year EFS and OS rates of 79% (95% CI, 56%-100%) and 93% (95% CI, 79%-100%), respectively. Eighteen patients who had diffuse anaplasia had 4-year EFS and OS rates of 61% (95% CI, 35%-88%) and 72% (95% CI, 47%-97%), respectively; and the 4-year EFS and OS rates of 7 patients who had focal anaplasia were 71% (95% CI, 38%-100%) and 100%, respectively. There was no difference in the outcomes of patients who had different histopathologic subtypes within the intermediate-risk group (P = .54). CONCLUSIONS: A risk-adapted treatment approach for BWT results in excellent outcomes. This approach was not successful in improving the outcome of patients who had diffuse anaplasia.

Kidney Preservation and Wilms Tumor Development in Children with Diffuse Hyperplastic Perilobar Nephroblastomatosis: A Report from the Children's Oncology Group Study AREN0534.

INTRODUCTION: Diffuse hyperplastic perilobar nephroblastomatosis (DHPLN) represents a unique category of nephroblastomatosis. Treatment has ranged from observation to multiple regimens of chemotherapy. Wilms tumors (WTs) develop in 100% of untreated patients and between 32 and 52% of treated patients. Renal preservation rates have not been previously reported. An aim of the Children's Oncology Group (COG) study AREN0534 was to prospectively evaluate the efficacy of chemotherapy in preserving renal units and preventing WT development in children with DHPLN. METHODS: Patients were enrolled through the COG protocol AREN03B2 with central radiological review. DHPLN was defined as the cortical surface of the kidney being composed of hyperplastic rests, with the entire nephrogenic zone involved, and with a thick rind capping all of one or both kidneys. Treatment was with vincristine and dactinomycin (regimen EE4A), with cross-sectional imaging at weeks 6 and 12. If the patient's disease was stable or decreasing, treatment was continued for 19 weeks. Renal preservation, WT development rates at 1 year, and overall survival (OS) are reported. RESULTS: Nine patients were enrolled (five females and four males), with a median age at enrollment of 10.22 months (range 2.92-29.11). One patient who was enrolled was deemed unevaluable because they did not meet the radiological criteria for DHPLN, resulting in eight evaluable patients. These eight patients had DHPLN confirmed via radiological criteria (all bilateral). Initial chemotherapy was EE4A for all eight patients, with seven of eight patients starting chemotherapy without tissue diagnosis.One patient who had an upfront partial nephrectomy was found to have DHPLN in the specimen and was subsequently treated with EE4A. All patients remained alive, with a median follow-up of 6.6 years (range 4.5-9.1). No patients were anephric; 14 of 16 kidneys were functioning (87.5%). Six of eight patients (75%) did not have WT on therapy, but two of these patients relapsed within 6 months of stopping therapy; both had favorable histology WT. One patient who was diagnosed with WT on therapy relapsed at 12 months (one of eight [12.5%]) and developed anaplastic histology. CONCLUSIONS: Chemotherapy for patients with DHPLN was effective in preserving kidney function. Five-year OS is excellent, however the ideal type and duration of chemotherapy to prevent WT development remains elusive.

Results of Treatment for Patients With Multicentric or Bilaterally Predisposed Unilateral Wilms Tumor (AREN0534): A report from the Children's Oncology Group.

BACKGROUND: A primary objective of Children's Oncology Group study AREN0534 (Treatment for Patients With Multicentric or Bilaterally Predisposed, Unilateral Wilms Tumor) was to facilitate partial nephrectomy in 25% of children with bilaterally predisposed unilateral tumors (Wilms tumor/aniridia/genitourinary anomalies/range of developmental delays [WAGR] syndrome; and multifocal and overgrowth syndromes). The purpose of this prospective study was to achieve excellent event-free survival (EFS) and overall survival (OS) while preserving renal tissue through preoperative chemotherapy, completing definitive surgery by 12 weeks from diagnosis, and modifying postoperative chemotherapy based on histologic response. METHODS: The treating institution identified whether a predisposition syndrome existed. Patients underwent a central review of imaging studies through the biology and classification study AREN03B2 and then were eligible to enroll on AREN0534. Patients were treated with induction chemotherapy determined by localized or metastatic disease on imaging (and histology if a biopsy had been undertaken). Surgery was based on radiographic response at 6 or 12 weeks. Further chemotherapy was determined by histology. Patients who had stage III or IV disease with favorable histology received radiotherapy as well as those who had stage I through IV anaplasia. RESULTS: In total, 34 patients were evaluable, including 13 males and 21 females with a mean age at diagnosis of 2.79 years (range, 0.49-8.78 years). The median follow-up was 4.49 years (range, 1.67-8.01 years). The underlying diagnosis included Beckwith-Wiedemann syndrome in 9 patients, hemihypertrophy in 9 patients, multicentric tumors in 10 patients, WAGR syndrome in 2 patients, a solitary kidney in 2 patients, Denys-Drash syndrome in 1 patient, and Simpson-Golabi-Behmel syndrome in 1 patient. The 4-year EFS and OS rates were 94% (95% CI, 85.2%-100%) and 100%, respectively. Two patients relapsed (1 tumor bed, 1 abdomen), and none had disease progression during induction. According to Response Evaluation Criteria in Solid Tumor 1.1 criteria, radiographic responses included a complete response in 2 patients, a partial response in 21 patients, stable disease in 11 patients, and progressive disease in 0 patients. Posttherapy histologic classification was low-risk in 13 patients (including the 2 complete responders), intermediate-risk in 15 patients, and high-risk in 6 patients (1 focal anaplasia and 5 blastemal subtype). Prenephrectomy chemotherapy facilitated renal preservation in 22 of 34 patients (65%). CONCLUSIONS: A standardized approach of preoperative chemotherapy, surgical resection within 12 weeks, and histology-based postoperative chemotherapy results in excellent EFS, OS, and preservation of renal parenchyma.

Clinical and laboratory outcomes following total or partial splenectomy in patients with hereditary spherocytosis.

This study compared outcomes following total (TS) or partial splenectomy (PS) among patients with hereditary spherocytosis. Seventy-nine patients (TS = 33, PS = 46) were identified. The follow-up period was longer after PS (59.6 vs. 24.9 months, p < .001). Long-term adverse events occurred more frequently following PS (50% vs. 29%, p = .001). Anemia, jaundice, and fatigue recurred in six patients with PS, leading to five completion splenectomies. Hemoglobin was not different between PS and TS by 5 years post-procedure (12.3 vs. 13.4 g/dL, p = .25). Both PS and TS ameliorate symptoms and improve hematologic parameters. The rate of secondary surgery following PS should be considered when planning the initial surgical procedure.

Results of the First Prospective Multi-institutional Treatment Study in Children With Bilateral Wilms Tumor (AREN0534): A Report From the Children's Oncology Group.

OBJECTIVE: The Children's Oncology Group study AREN0534 aimed to improve event-free survival (EFS) and overall survival (OS) while preserving renal tissue by intensifying preoperative chemotherapy, completing definitive surgery by 12 weeks from diagnosis, and modifying postoperative chemotherapy based on histologic response. BACKGROUND: No prospective therapeutic clinic trials in children with bilateral Wilms tumors (BWT) exist. Historical outcomes for this group were poor and often involved prolonged chemotherapy; on NWTS-5, 4-year EFS for all children with BWT was 56%. METHODS: Patients were enrolled and imaging studies were centrally reviewed to assess for bilateral renal lesions. They were treated with 3-drug induction chemotherapy (vincristine, dactinomycin, and doxorubicin) for 6 or 12 weeks based on radiographic response followed by surgery and further chemotherapy determined by histology. Radiation therapy was provided for postchemotherapy stage III and IV disease. RESULTS: One hundred eighty-nine of 208 patients were evaluable. Four-year EFS and OS were 82.1% (95% CI: 73.5%-90.8%) and 94.9% (95% CI: 90.1%-99.7%. Twenty-three patients relapsed and 7 had disease progression. After induction chemotherapy 163 of 189 (84.0%) underwent definitive surgical treatment in at least 1 kidney by 12 weeks and 39% retained parts of both kidneys. Surgical approaches included: unilateral total nephrectomy with contralateral partial nephrectomy (48%), bilateral partial nephrectomy (35%), unilateral total nephrectomy (10.5%), unilateral partial nephrectomy (4%), and bilateral total nephrectomies (2.5%). CONCLUSION: This treatment approach including standardized 3-drug preoperative chemotherapy, surgical resection within 12 weeks of diagnosis and response and histology-based postoperative therapy improved EFS and OS and preservation of renal parenchyma compared with historical outcomes for children with BWT.

Clinical Outcome and Biological Predictors of Relapse After Nephrectomy Only for Very Low-risk Wilms Tumor: A Report From Children's Oncology Group AREN0532.

OBJECTIVE: To determine if observation alone after nephrectomy in very low-risk Wilms tumor (defined as stage I favorable histology Wilms tumors with nephrectomy weight <550g and age at diagnosis <2 years) results in satisfactory event-free survival and overall survival, and to correlate relapse with biomarkers. PATIENTS AND METHODS: The AREN0532 study enrolled patients with very low-risk Wilms tumor confirmed by central review of pathology, diagnostic imaging, and surgical reports. After nephrectomy, patients were followed without adjuvant chemotherapy. Evaluable tumors were analyzed for WT1mutation, 1p and 16q copy loss, 1q copy gain, and 11p15 imprinting. The study was powered to detect a reduction in 4-year EFS from 87% to 75% and overall survival from 95% to 88%. RESULTS: A total of 116 eligible patients enrolled with a median follow up of 80 months (range: 5-97 months). Twelve patients relapsed. Estimated 4-year event-free survival was 89.7% (95% confidence interval 84.1-95.2%) and overall survival was 100%. First sites of relapse were lung (n = 5), tumor bed (n = 4), and abdomen (n = 2), with one metachronous tumor in the contralateral kidney (n = 1) at a median time of 4.3 months for those who relapsed (range 2.3-44 months). The presence of intralobar (P = 0.46) or perilobar rests (P = 1.0) were not associated with relapse (P = 0.16). 1q gain, 1p and 16q loss, and WT1 mutation status were not associated with relapse. 11p15 methylation status was associated relapse (20% relapse with loss of heterozygosity, 25% with loss of imprinting, and 3.3% relapse with retention of the normal imprinting (P = 0.011)). CONCLUSIONS: Most patients meeting very low-risk criteria can be safely managed by nephrectomy alone with resultant reduced exposure to chemotherapy. Expansion of an observation alone strategy for low-risk Wilms tumor incorporating both clinical features and biomarkers should be considered.

Postoperative Complications in Children With Crohn Disease Treated With Infliximab.

OBJECTIVES: Infliximab (IFX) has become a mainstay of therapy for children with Crohn disease (CD). Despite medical advances, many children with CD, however, still require operative interventions. The risk of complications following resection in children treated with IFX remains largely unknown. We compare surgical outcomes stratified by IFX therapy in a cohort of children with CD who require bowel resection. METHODS: We reviewed the postoperative complications in 123 children with CD who underwent bowel resection with primary anastomosis at our institution between 1977 and 2011. Demographics, medications, types of operations, and inpatient courses were analyzed. Complications and length of stay were compared based on medical therapy. RESULTS: Overall, the postoperative complication rate was 13%. Of the 123 surgical cases, 24 children had received IFX before their operation. In the children treated with IFX, we identified 3 major complications, including anastomotic leak, acute renal failure, and intraabdominal abscess. There were 9 major complications in the non-IFX group, including infections (2), intraabdominal abscesses (2), bowel obstruction, shock, supraventricular tachycardia, phlegmon, and anastomotic stricture. No significant differences in complication rates or postoperative lengths of stay were identified between those who did or did not receive IFX. CONCLUSIONS: In this cohort, surgical procedures in children and young adults treated with IFX were not associated with an increased number of complications or prolonged length of stay. Given that postoperative complications are infrequent in children, larger multicenter studies may be required to determine whether IFX therapy increases the risk of surgical complications in pediatric CD.

Comparative evaluation of local control strategies in localized Ewing sarcoma of bone: a report from the Children's Oncology Group.

BACKGROUND: Patients with Ewing sarcoma require local primary tumor control with surgery, radiation, or both. The optimal choice of local control for overall and local disease control remains unclear. METHODS: Patients with localized Ewing sarcoma of bone who were treated on 3 consecutive protocols with standard-dose, 5-drug chemotherapy every 3 weeks were included (n=465). Propensity scores were used to control for differences between local control groups by constructing multivariate models to assess the impact of local control type on clinical endpoints (event-free survival [EFS], overall survival, local failure, and distant failure) independent of differences in their propensity to receive each local control type. RESULTS: Patients who underwent surgery were younger (P=.02) and had more appendicular tumors (P<.001). Compared with surgery, radiation had higher unadjusted risks of any event (hazard ratio [HR], 1.70; 95% confidence interval [CI], 1.18-2.44), death (HR, 1.84; 95% CI, 1.18-2.85), and local failure (HR, 2.57; 95% CI, 1.37-4.83). On multivariate analysis, compared with surgery, radiation had a higher risk of local failure (HR, 2.41; 95% CI, 1.24-4.68), although there were no significant differences in EFS (HR, 1.42; 95% CI, 0.94-2.14), overall survival (HR, 1.37; 95% CI, 0.83-2.26), or distant failure (HR, 1.13; 95% CI, 0.70-1.84) between local control groups. CONCLUSIONS: In this large group of similarly treated patients, choice of the mode of local control was not related significantly to EFS, overall survival, or distant failure, although the risk of local failure was greater for radiation compared with surgery. These data support surgical resection when appropriate, whereas radiotherapy remains a reasonable alternative in selected patients.

How are childhood thyroid nodules discovered: opportunities for improving early detection.

In a retrospective analysis of childhood thyroid nodules, 18% were radiographic incidentalomas and 41% were discovered by a clinician's palpation; 40% were discovered by patients' families. The latter group had the largest nodules and highest rates of thyroid cancer metastasis, suggesting opportunities for earlier detection through annual well-child visits.

Outcome of patients with Stage II/favorable histology Wilms tumor with and without local tumor spill: a report from the National Wilms Tumor Study Group.

BACKGROUND: Intra-operative tumor spill increases the risk of local recurrence of Wilms tumor, and adversely impacts relapse-free (RFS) and overall survival (OS) rates. METHODS: Surgical checklists, operative notes, institutional pathology reports, central pathology review and flow sheets of 602 patients registered between August 1986 and September 1994 on National Wilms Tumor Study-4 as randomized, followed or switched and coded as Final Stage II, favorable histology (FH) were reviewed. RFS and OS were estimated using the Kaplan-Meier method. Hazard ratios (HRs) were estimated using the Cox model and tested for statistical significance by the log-rank test. RESULTS: Four hundred ninety-nine patients were found after review to have Stage II, FH Wilms tumor. The 8-year RFS percentages were 85.0% (95% confidence interval (CI): 81.1%, 88.1%) for those with no spill compared to 75.7% (65.8%, 83.2%) for those with spill. The 8-year OS percentages were 95.6% (93.1%, 97.3%) for those with no spill compared to 90.3% (82.2%, 94.9%) for those with spill. The HR for relapse among those with spill was 1.55 ((95%CI: 0.97,2.51), P = 0.067) and the HR for death was 1.94 ((0.92,4.09), P = 0.077). CONCLUSIONS: RFS and OS were lower for patients who had intra-operative tumor spill. The majority of NWTS Stage II, FH patients with intra-operative tumor spill have an overall excellent outcome when treated with two drug chemotherapy (vincristine and actinomycin D) and no abdominal irradiation.

Patterns of recurrence after radiotherapy for high-risk neuroblastoma: Implications for radiation dose and field.

BACKGROUND: Prognosis for patients with high-risk neuroblastoma (HR-NBL) is guarded despite aggressive therapy, and few studies have characterized outcomes after radiotherapy in relation to radiation treatment fields. METHODS: Multi-institutional retrospective cohort of 293 patients with HR-NBL who received autologous stem cell transplant (ASCT) and EBRT between 1997-2021. LRR was defined as recurrence at the primary site or within one nodal echelon beyond disease present at diagnosis. Follow-up was defined from the end of EBRT. Event-free survival (EFS) and OS were analyzed by Kaplan-Meier method. Cumulative incidence of locoregional progression (CILP) was analyzed using competing risks of distant-only relapse and death with Gray's test. RESULTS: Median follow-up was 7.0 years (range: 0.01-22.4). Five-year CILP, EFS, and OS were 11.9 %, 65.2 %, and 77.5 %, respectively. Of the 31 patients with LRR and imaging review, 15 (48.4 %) had in-field recurrences (>12 Gy), 6 (19.4 %) had marginal failures (≤12 Gy), and 10 (32.3 %) had both in-field and marginal recurrences. No patients receiving total body irradiation (12 Gy) experienced marginal-only failures (p = 0.069). On multivariable analyses, MYCN amplification had higher risk of LRR (HR: 2.42, 95 % CI: 1.06-5.50, p = 0.035) and post-consolidation isotretinoin and anti-GD2 antibody therapy (HR: 0.42, 95 % CI: 0.19-0.94, p = 0.035) had lower risk of LRR. CONCLUSIONS: Despite EBRT, LRR remains a contributor to treatment failure in HR-NBL with approximately half of LRRs including a component of marginal failure. Future prospective studies are needed to explore whether radiation fields and doses should be defined based on molecular features such as MYCN amplification, and/or response to chemotherapy.

Outcome after reduced chemotherapy for intermediate-risk neuroblastoma.

BACKGROUND: The survival rate among patients with intermediate-risk neuroblastoma who receive dose-intensive chemotherapy is excellent, but the survival rate among patients who receive reduced doses of chemotherapy for shorter periods of time is not known. METHODS: We conducted a prospective, phase 3, nonrandomized trial to determine whether a 3-year estimated overall survival of more than 90% could be maintained with reductions in the duration of therapy and drug doses, using a tumor biology-based therapy assignment. Eligible patients had newly diagnosed, intermediate-risk neuroblastoma without MYCN amplification; these patients included infants (<365 days of age) who had stage 3 or 4 disease, children (≥365 days of age) who had stage 3 tumors with favorable histopathological features, and infants who had stage 4S disease with a diploid DNA index or unfavorable histopathological features. Patients who had disease with favorable histopathological features and hyperdiploidy were assigned to four cycles of chemotherapy, and those with an incomplete response or either unfavorable feature were assigned to eight cycles. RESULTS: Between 1997 and 2005, a total of 479 eligible patients were enrolled in this trial (270 patients with stage 3 disease, 178 with stage 4 disease, and 31 with stage 4S disease). A total of 323 patients had tumors with favorable biologic features, and 141 had tumors with unfavorable biologic features. Ploidy, but not histopathological features, was significantly predictive of the outcome. Severe adverse events without disease progression occurred in 10 patients (2.1%), including secondary leukemia (in 3 patients), death from infection (in 3 patients), and death at surgery (in 4 patients). The 3-year estimate (±SE) of overall survival for the entire group was 96±1%, with an overall survival rate of 98±1% among patients who had tumors with favorable biologic features and 93±2% among patients who had tumors with unfavorable biologic features. CONCLUSIONS: A very high rate of survival among patients with intermediate-risk neuroblastoma was achieved with a biologically based treatment assignment involving a substantially reduced duration of chemotherapy and reduced doses of chemotherapeutic agents as compared with the regimens used in earlier trials. These data provide support for further reduction in chemotherapy with more refined risk stratification. (Funded by the National Cancer Institute; ClinicalTrials.gov number, NCT00003093.)

Critical elements of radical nephroureterectomy for pediatric unilateral renal tumor.

Children with renal masses require surgical management to provide accurate surgical staging and skilled resection of the tumor. This document includes evidence-based recommendations for pediatric surgeons regarding the resection, staging, and proper nodal basin evaluation.

Critical elements of pediatric neuroblastoma surgery.

Neuroblastoma (NB) is the most common solid extracranial malignancy of childhood with an incidence of 1 per 100,000 in the United States compromising approximately 10 % of childhood cancer. Unfortunately, patients with high-risk NG continue to have long-term survival less than 50 %. Both Children's Oncology Group and the International Society of Paediatric Oncology have demonstrated the important role of surgery in the treatment of high-risk NB. Herein, we compose the results of an extensive literature review as well as expert opinion from leaders in pediatric surgical oncology, to present the critical elements of effective surgery for high-risk neuroblastoma.