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.

Impact of cyclophosphamide and etoposide on outcome of clear cell sarcoma of the kidney treated on the National Wilms Tumor Study-5 (NWTS-5).

PURPOSE: To improve the event-free survival (EFS) and overall survival (OS) for patients with clear cell sarcoma of the kidney (CCSK) by incorporating cyclophosphamide and etoposide into treatment on National Wilms Tumor Study (NWTS)-5. PATIENTS AND METHODS: Patients less than 16 years of age with a centrally confirmed pathological diagnosis of CCSK were eligible for treatment on this prospective single-arm study conducted between August 1995 and June 2002. Staging consisted of CT scans of chest, abdomen, pelvis, bone scan, skeletal survey, and CT or MRI of the head. Treatment consisted of vincristine/doxorubicin/cyclophosphamide alternating with cyclophosphamide/etoposide for 24 weeks and radiation to sites of disease. RESULTS: One hundred eight eligible patients were enrolled on study (69% males, 63% Caucasian), with a median age of 22 months. Stage distribution was as follows: stage I, 12; II, 44; III, 45; IV, 7. Median follow-up was 9.7 years. Five-year EFS and OS were 79% (95% CI: 71%-88%) and 90% (95% CI: 84%-96%). Five-year EFS for stage I-IV was 100%, 88%, 73%, and 29%, respectively. Twenty of the 23 disease-related events occurred within three years of initial treatment. The most common site of recurrence was brain (12/23). CONCLUSION: The outcome for patients with CCSK treated on NWTS-5 was similar to NWTS-4 and accomplished over a shorter treatment duration. Stage was highly predictive of outcome. Brain metastases occurred more frequently than on NWTS-4. Regimen I showed more benefit for patients with stage I and II disease as compared with higher stages of disease where new therapies are needed.

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.

Patterns of Performance of Oncologic Surgery by North American Pediatric Urologists: A Report from the Pediatric Urologic Oncology Working Group of the Society for Pediatric Urology.

PURPOSE: Objective data on patterns of oncology practice among pediatric urologists are lacking. We reviewed surgical case logs submitted to the American Board of Urology by those self-reporting as pediatric urologists. We hypothesized that logs would reveal a low oncology volume (fewer than 5 cases) and identify orchiectomy as the most common oncology cases, and that less than 25% of logs would show nephrectomy for renal tumor. MATERIALS AND METHODS: Case logs submitted for American Board of Urology certification, recertification or pediatric subspecialty certification were reviewed and standardized to represent 12-month practice. Data were collected on pediatric oncologic surgeries as noted by procedure codes linked with oncologic diagnosis codes for patients up to age 30 years. RESULTS: We identified 281 case logs meeting study criteria. A total of 364 oncology cases were logged and 131 logs (46.6%) listed at least 1 oncology case, while 150 (53.4%) contained no oncology cases. The 75th, 90th and 95th percentiles of oncology volume were represented by reporting 2, 3 and 4 cases, respectively. A total of 13 logs (4.6%) accounted for more than a third of all oncology cases (35.9%). The most frequent oncology case logged was orchiectomy, which was documented in 83 logs (29.5%). On Poisson regression surgeon variables associated with higher oncology volume included male gender (IRR 2.8, 95% CI 2.1-3.9), 2010 log year (IRR 2.4, 95% CI 1.3-4.4), 2015 log year (IRR 3.7, 95% CI 2.1-6.4) and nonpediatric subspecialty certification log (IRR 1.6, 95% CI 1.2-2.3). CONCLUSIONS: Few pediatric urologists perform a high volume of oncologic surgeries based on surgical case logs submitted to the American Board of Urology. A small cohort of pediatric urologists logged the majority of such cases.

A Society for Pediatric Urology Workforce Survey on the Current Perceptions of Oncology Care by Pediatric Urologists: A Report from the Pediatric Urologic Oncology Working Group of the Society for Pediatric Urology.

PURPOSE: Data are lacking on the current perception of oncology care among pediatric urologists. Thus, we developed, pilot tested and administered a survey on this topic to SPU (Society for Pediatric Urology) members. MATERIALS AND METHODS: Approval for this proposal was granted by SPU leadership prior to developing or distributing the survey instrument. The survey was developed and pilot tested by the PUOWG (Pediatric Urologic Oncology Working Group). Response data were collected and descriptive statistics were used for analysis. Logistic regression analysis was performed to correlate surgeon reported factors with higher volumes of reported oncology surgery. RESULTS: A total of 426 surveys were distributed via email to SPU members and 212 individual surveys (49.8%) were returned with the background/introduction section completed. Of these surveys 200 (94.3%) were completed by practicing pediatric urologists. Overall, 155 respondents (77.5%) reported performing 5 or fewer oncology related surgeries per year and 74.9% reported that less than 25% of renal tumor surgery at their institution was performed through the pediatric urology service. On multivariate analysis the self-reported factors significantly associated with increased oncology surgical volume (more than 5 cases per year) were greater than 50% attendance at institutional tumor board meetings (OR 4.8, 95% CI 1.4-16.9) and practicing at a hospital with a higher volume of renal tumor surgery (OR 2.6, 95% CI 1.2-5.8). CONCLUSIONS: Few surveyed pediatric urologists reported performing a high volume of oncology surgery. Respondents expressed interest in ways to increase pediatric urology involvement in oncology care, including opportunities for increased education. Self-reported factors that correlated with higher volume were regular attendance at the institutional pediatric tumor board and practice at a higher volume institution.

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.

Is adrenalectomy necessary during unilateral nephrectomy for Wilms Tumor? A report from the Children's Oncology Group.

PURPOSE: To determine whether performing adrenalectomy at the time of nephrectomy for unilateral Wilms tumor impacts clinical outcome. METHODS: We reviewed information on all patients enrolled on National Wilms Tumor Study-4 and -5. Data were abstracted on patient demographics, tumor characteristics, surgical and pathologic status of the adrenal gland, and patient outcomes. The primary endpoints were intraoperative spill and five-year event-free survival (EFS) in patients who did or did not undergo adrenalectomy. RESULTS: Of 3825 patients with complete evaluable data, the adrenal was left in situ in 2264 (57.9%) patients, and was removed completely in 1367 patients (36.7%) or partially in 194 patients (5.2%). Of the adrenal glands removed, 68 (4.4%) contained tumor. Adrenal involvement was more common in patients with stage 3 (9.8%) than stage 2 disease (1.9%; p < 0.0001). After controlling for stage and histopathology, five-year EFS was similar whether or not the adrenal gland was removed (p = 0.48), or involved with tumor (p = 0.81); however, intraoperative spill rates were higher in patients undergoing adrenalectomy (26.1% vs 15.5%, p < 0.0001), likely due to larger tumor size or technical factors. No patient had clinical evidence of adrenal insufficiency or tumor recurrence in the adrenal gland during follow-up (median 9.9 years). CONCLUSIONS: Sparing the adrenal gland during nephrectomy for unilateral Wilms tumor was not associated with a higher incidence of intraoperative spill and was associated with a similar oncologic outcome, on a per-stage basis, with cases where the adrenal was removed. Thus, adrenalectomy should not be considered mandatory during radical nephrectomy for Wilms tumor.

Clinicopathologic findings predictive of relapse in children with stage III favorable-histology Wilms tumor.

PURPOSE: Stage III designation in NWTS-5 (National Wilms Tumor Study-5) was determined by four pathologic criteria: positive lymph nodes (LNs), peritoneal implants, residual disease, and tumor rupture. The objective of this study was to determine the prognostic significance of each of the stage III criteria. PATIENTS AND METHODS: Children with stage III Wilms tumor (WT) treated in NWTS-5 were assessed for event-free (EFS) and overall survival (OS). Sites of relapse and molecular status of tumors are reported. EFS and OS are reported 8 years after diagnosis. RESULTS: There were 569 patients with local stage III favorable-histology (FH) WT in this analysis, of whom 109 had overall stage IV disease. LN involvement alone was the most frequent criterion for stage III designation (38%), followed by microscopic residual disease alone (20%), microscopic residual disease and LN involvement (14%), and spill or soilage alone (9%). The 8-year EFS and OS estimates for all patients with local stage III FHWT were 82% and 91%, respectively. Multivariate analysis demonstrated that both LN involvement (relative risk, 1.89; P = .005) and microscopic residual disease (relative risk, 1.87; P = .007) were predictive of EFS, and OS results were similar. There was no apparent difference in pattern of relapse according to stage III subtype. The rate of loss of heterozygosity was higher (6%) for those with positive LNs than for those without (2%; P = .05). CONCLUSION: LN involvement and microscopic residual are the stage III criteria highly predictive of EFS and OS for patients with stage III FHWT. It is possible that in future studies, patients with different stage III criteria may receive different therapies.

Primary nephrectomy and intraoperative tumor spill: report from the Children's Oncology Group (COG) renal tumors committee.

PURPOSE: Initial Children's Oncology Group (COG) management for Wilms' tumor (WT) consists of primary nephroureterectomy with lymph node sampling. While this provides accurate staging to define further treatment, it may result in intraoperative spill (IOS), which is associated with higher recurrence rates and therefore requires more intensive therapy. The purpose of this study is to determine current rates and identify factors which may predispose a patient to IOS. METHODS: The study population was drawn from the AREN03B2 renal tumor banking and classification study of the Children's Oncology Group. All children with a first time occurrence of a renal mass were eligible for the study. At the time of enrollment and prior to risk stratification, the institution is required to submit operative notes, pathology specimens, a chest computed tomography scan (CT), and a contrast-enhanced CT or magnetic resonance imaging (MRI) of the abdomen and pelvis for central imaging review. These data are then used to determine an initial risk classification and therapeutic protocol eligibility. Patients who had a unilateral nephroureterectomy for favorable histology WT underwent further review to assure data accuracy and to clarify details regarding the spill. Analyses were performed using chi square and logistic regression. Odd ratios (OR) are shown with 95% confidence intervals. RESULTS: There were 1,131 primary nephrectomies for unilateral WT with an IOS rate of 9.7% with an additional 1.8% having possible tumor spill during renal vein or IVC tumor thrombectomy. IOS correlated with diameter (>12 cm, p<0.0001) and laterality (right, p=0.0414). Simple logistic regression indicated that IOS increased 2.7% [p=0.0240, OR 1.027 (1.004, 1.052)] with each 1 cm increase in diameter (3 - 21 cm) and 4.7% [p=0.0147 OR 1.047 (1.009, 1.086)] with each 100 g increase in weight (80 - 1800 g). Multiple logistic regression indicated that laterality [right p=0.048, OR 1.46 (1.004, 2.110)] and weight (p=0.03, OR 1.039 (1.003, 1.075) were predictive of IOS when diameter was included as a continuous variable. Diameter as a binary variable was highly prognostic of IOS (p=0.0002), while laterality and weight were not significant. CONCLUSIONS: Intraoperative tumor spill occurs in about one out of every ten cases of primary nephroureterectomies for WT. Right-sided and larger tumors are at higher risk of IOS.

Paediatric genitourinary cancers and late effects of treatment.

The most common childhood genitourinary cancers are Wilms tumour, rhabdomyosarcoma and germ cell tumour (GCT). Long-term survival rates for patients with these tumours are generally excellent, ranging from 80% to 100%. However, the high cure rates have highlighted the need to minimize the long-term complications of treatments (referred to as 'late effects'), which can be caused by the three treatment modalities used to treat genitourinary tumours: surgery, chemotherapy and radiation therapy. Serious late effects, such as death, second cancers and tumour recurrence, are uncommon but do occur occasionally. Chronic health conditions--such as cardiac, pulmonary and fertility disorders--are more prevalent. Given the high prevalence of late effects, survivors of childhood genitourinary malignancies require regular surveillance and health promotion delivered by health-care providers with specialist knowledge of the long-term complications of treatment.

Pediatric urologic oncology.

This article reviews common pediatric urologic cancers involving the genitourinary system. Rhabdomyosarcoma may occur in the bladder, prostate, paratesticular regions, vagina, or uterus. Some of these locations, such as the paratesticular region, have a more favorable outcome. Benign neoplasms account for the majority of pediatric testicular tumors and most are managed with testis-sparing surgery. Most genitourinary malignancies are expected to have a good outcome. One focus of treatment is organ preservation but not at the expense of a good oncologic outcome. Late sequelae of anticancer therapy are a concern and every attempt is made to decrease the intensity of tumor treatment.

Lymph node involvement in Wilms tumor: results from National Wilms Tumor Studies 4 and 5.

PURPOSE: The aim of the study was to determine the prognostic impact of lymph node (LN) involvement and sampling in patients with Wilms tumor (WT) and the minimum number of LNs needed for accurate staging. METHODS: We reviewed all patients with unilateral, nonmetastatic WT enrolled in the National Wilms Tumor Study 4 or 5. Data were abstracted on patient demographics, tumor histology, staging, number of LNs sampled, and disease-specific and overall patient outcomes. RESULTS: A total of 3409 patients had complete information on LN sampling. Five-year event-free survival (EFS) was lower in patients with nodal disease (P < .001); the effect of LN positivity was greater for patients with anaplastic (P = .047) than with favorable histology (P = .02). The likelihood of obtaining a positive LN was higher when sampling at least 7 LNs. However, after controlling for tumor histology and stage, the number of LNs sampled did not predict EFS variations (P = .75). Among patients with stage II disease, patients with LN sampling (P = .055) had improved EFS, largely reflecting poorer EFS in patients with anaplastic tumors (P = .03). CONCLUSIONS: Lymph node sampling is particularly important for patients with stage II anaplastic WT. Although the likelihood of finding a positive LN was greater when more than 7 LNs were sampled, EFS was not impacted by the number of LNs sampled.

Treatments and outcomes for end-stage renal disease following Wilms tumor.

BACKGROUND: Little is known about treatment outcomes for children who have end-stage renal disease (ESRD) after treatment for Wilms tumor (WT). METHODS: Time-to-transplant, graft failure, and survival outcomes were examined for 173 children enrolled on the National Wilms Tumor Study who developed ESRD. RESULTS: Fifty-five patients whose ESRD resulted from progressive bilateral WT (PBWT) experienced high early mortality from WT that limited their opportunity for transplant (47% at 5 years) and survival (44% at 10 years) in comparison to population controls. The 118 patients whose ESRD was due to other causes (termed "chronic kidney disease"), many of whom had WT-associated congenital anomalies, had transplant (77% at 5 years) and survival (73% at 10 years) outcomes no worse than those for population controls. Graft failure following transplant was comparable for the two groups. Minority children had twice the median time to transplant as non-Hispanic whites and twice the mortality rates, also reflecting population trends. CONCLUSIONS: In view of the continuing high mortality in patients with ESRD, and the dramatic improvement in outlook following kidney transplantation, re-evaluation of current guidelines for a 2-year delay in transplant following WT treatment may be warranted.

Risk factors for end stage renal disease in non-WT1-syndromic Wilms tumor.

PURPOSE: We assessed risk factors for end stage renal disease in patients with Wilms tumor without known WT1 related syndromes. We hypothesized that patients with characteristics suggestive of a WT1 etiology (early onset, stromal predominant histology, intralobar nephrogenic rests) would have a higher risk of end stage renal disease due to chronic renal failure. We predicted a high risk of end stage renal disease due to progressive bilateral Wilms tumor in patients with metachronous bilateral disease. MATERIALS AND METHODS: End stage renal disease was ascertained in 100 of 7,950 nonsyndromic patients enrolled in a National Wilms Tumor Study during 1969 to 2002. Risk factors were evaluated with cumulative incidence curves and proportional hazard regressions. RESULTS: The cumulative incidence of end stage renal disease due to chronic renal failure 20 years after Wilms tumor diagnosis was 0.7%. For end stage renal disease due to progressive bilateral Wilms tumor the incidence was 4.0% at 3 years after diagnosis in patients with synchronous bilateral Wilms tumor and 19.3% in those with metachronous bilateral Wilms tumor. For end stage renal disease due to chronic renal failure stromal predominant histology had a HR of 6.4 relative to mixed (95% CI 3.4, 11.9; p<0.001), intralobar rests had a HR of 5.9 relative to no rests (95% CI 2.0, 17.3; p=0.001), and Wilms tumor diagnosis at less than 24 months had a HR of 1.7 relative to 24 to 48 months and 2.8 relative to greater than 48 months (p=0.003 for trend). CONCLUSIONS: Metachronous bilateral Wilms tumor is associated with high rates of end stage renal disease due to surgery for progressive Wilms tumor. Characteristics associated with a WT1 etiology markedly increased the risk of end stage renal disease due to chronic renal failure despite the low risk in non-WT1 syndromic cases overall.

Do chief resident scores on the in-service examination predict their performance on the American Board of Urology Qualifying Examination?

PURPOSE: The American Urological Association In-Service Examination and the American Board of Urology Qualifying Examination are written multiple choice tests that cover all domains in urology. We investigated whether In-Service Examination performance could identify chief residents who scored in the lowest quartile on the Qualifying Examination. MATERIALS AND METHODS: All urology chief residents in the United States and Canada in 2008 and 2009 were eligible to participate in this study. In-Service Examination 2008 and Qualifying Examination 2009 performance data were obtained from the American Urological Association and American Board of Urology, respectively. Data were analyzed with the Pearson correlation and descriptive statistics. RESULTS: Of the 257 American and Canadian chief residents who completed the Qualifying Examination 2009, 194 (75%) enrolled in this study and were included in analysis. Overall In-Service Examination 2008 scores correlated significantly with Qualifying Examination 2009 scores (r=0.55, p<0.001), accounting for 30% of score variance. Substantial variability in In-Service Examination-Qualifying Examination rankings was notable among individual residents. An In-Service Examination 2008 cutoff percentile rank of 40% identified chief residents in the lowest quartile on the Qualifying Examination 2009 with 71% sensitivity, 77% specificity, and a likelihood ratio of 3.1 and 0.4 (positive and negative likelihood ratios, respectively). CONCLUSIONS: The substantial variability of In-Service Examination-Qualifying Examination performance among individual chief residents limits In-Service Examination predictive utility. A single In-Service Examination score should not be used to make a high stakes judgment about an individual resident. In-Service Examination scores should be used as 1 part of an overall evaluation program to prospectively identify residents who could benefit from additional educational support.