The treatment of Wilms' tumor: results of the Second National Wilms' Tumor Study

Relevance of historical therapeutic approaches to the contemporary treatment of pediatric solid tumors

Children with solid tumors, most of which are malignant, have an excellent prognosis when treated on contemporary regimens. These regimens, which incorporate chemotherapeutic agents and treatment modalities used for many decades, have evolved to improve relapse-free survival and reduce long-term toxicity. This review discusses the evolution of the treatment regimens employed for management of the most common solid tumors, emphasizing the similarities between contemporary and historical regimens. These similarities allow the use of historical patient cohorts to identify the late effects of successful therapy and to evaluate remedial interventions for these adverse effects.

The evolution of treatment for Wilms tumor

The prognosis for children with Wilms tumor (WT) has improved dramatically as the result of advances in surgical techniques, anesthesia, and supportive care. During the last three decades, the National Wilms Tumor Study Group (NWTSG), the International Society of Pediatric Oncology (SIOP), and the United Kingdom Children's Cancer Study Group (UKCCSG) conducted sequential studies of treatments for children with WT. The National Wilms Study Group demonstrated that radiation therapy is not necessary for those with Stage I and II, favorable histology Wilms tumor, and that the dose necessary for local control for those with local Stage III disease is 1050 to 1080 cGy. Administration of actinomycin D and doxorubicin using a single dose rather than divided dose schedule produced less myelosuppression and equivalent outcomes. Loss of heterozygosity for chromosomes 1p and 16q was associated with an inferior outcome. Areas for future investigation include the role of whole lung irradiation in the treatment of those with pulmonary metastases, the use of parenchymal sparing surgical techniques for removal of Wilms tumors, and identification of minimal necessary therapy.

Cooperative group trials in pediatric oncology: the surgeon's role

The early history of the pediatric cooperative group trials is reviewed, and the surgeons who played a critical role in their formation are discussed. The vital information provided from the tumor specimens submitted as part of the protocols is presented, as well as how this information advanced our management of infants and children treated on current protocols of the Children's Oncology Group. Finally, a survey of the surgeons currently active in the clinical trials defined the "critical lessons" learned from the sequence of protocols by the cooperative groups which have advanced our surgical treatment of patients today.

Clinical significance of pulmonary nodules detected by CT and Not CXR in patients treated for favorable histology Wilms tumor on national Wilms tumor studies-4 and -5: a report from the Children's Oncology Group

BACKGROUND

Metastatic lung disease in Wilms tumor (WT) patients was traditionally identified by chest radiograph (CXR). It is unclear whether patients with small lesions, detectable only by computed tomography ("CT-only" lesions), require the more intensive therapy, including doxorubicin and lung irradiation, given to patients with metastases detectable by CXR.

PROCEDURES

This study involved 417 patients with favorable histology WT and isolated lung metastases (detected by CXR or CT) who were registered on National Wilms tumor Study (NWTS)-4 or -5. Outcomes by method of detection (CXR vs. CT-only), use of lung radiation, and 2- or 3-drug chemotherapy (dactinomycin and vincristine ± doxorubicin) were determined and compared using the log-rank test.

RESULTS

There were 231 patients with lung lesions detected by CXR and 186 by CT-only. Of the patients with CT-only nodules, 37 received only 2 drugs and 101 did not receive lung radiation. Five-year event-free survival (EFS) was greater for patients receiving three drugs (including doxorubicin) with or without lung radiation than for those receiving two drugs (80% vs. 56%; P = 0.004). There was no difference seen in 5-year overall survival (OS) between the 3- and 2-drug subsets (87% vs. 86%; P = 0.91). There were no significant differences in EFS (82% vs. 72%; P = 0.13) or OS (91% vs. 83%; P = 0.46) for patients with CT-only nodules whether they received lung radiation or not.

CONCLUSIONS

Our results suggest that patients with CT-only lung lesions may have improved EFS but not OS from the addition of doxorubicin but do not appear to benefit from pulmonary radiation.

Outcomes of patients with revised stage I clear cell sarcoma of kidney treated in National Wilms Tumor Studies 1-5

PURPOSE

To report the clinical outcomes of children with revised stage I clear cell sarcoma of the kidney (CCSK) using the National Wilms Tumor Study Group (NWTS)-5 staging criteria after multimodality treatment on NWTS 1-5 protocols.

METHODS AND MATERIALS

All CCSK patients enrolled in the National Wilms Tumor Study Group protocols had their pathology slides reviewed, and only those determined to have revised stage I tumors according to the NWTS-5 staging criteria were included in the present analysis. All patients were treated with multimodality therapy according to the NWTS 1-5 protocols.

RESULTS

A total of 53 children were identified as having stage I CCSK. All patients underwent primary surgery with radical nephrectomy. The chemotherapy regimens used were as follows: regimen A, C, F, or EE in 4 children (8%); regimen DD or DD4A in 33 children (62%); regimen J in 4 children (8%); and regimen I in 12 children (22%). Forty-six patients (87%) received flank radiation therapy (RT). Seven children (13%) did not receive flank RT. The median delay between surgery and the initiation of RT was 9 days (range, 3-61). The median RT dose was 10.8 Gy (range, 10-36). The flank RT doses were as follows: 10.5 or 10.8 Gy in 25 patients (47%), 11-19.9 Gy in 2 patients (4%), 20-29.9 Gy in 9 patients (17%), and 30-40 Gy in 10 patients (19%). The median follow-up for the entire group was 17 years (range, 2-36). The relapse-free and cancer-specific survival rate was 100% at the last follow-up examination.

CONCLUSIONS

The present results have demonstrated that children with revised stage I CCSK using the NWTS-5 staging criteria have excellent survival rates despite the use of varying RT doses and chemotherapy regimens in the NWTS 1-5 protocols.

Wilms tumor

Significant improvement has been made in the treatment of children with Wilms tumor. New protocols are in place designed to maintain a high rate of cure for these patients while minimizing toxicity, based on refinement of the risk-stratification system.

A Surveillance, Epidemiology and End Results (SEER) program comparison of adult and pediatric Wilms' tumor

PURPOSE

To compare the characteristics and outcome of adults and children diagnosed with Wilms' tumor.

METHODS

The Surveillance, Epidemiology and End Results (SEER) database was analyzed for patients diagnosed with Wilms' tumor between 1973 and 2007. Patients were stratified into pediatric (<16 years) or adult (≥16 years) groups. Overall survival was the primary endpoint.

RESULTS

A total of 2342 patients (2190 pediatric and 152 adult) with Wilms' tumor were identified. Adult patients were statistically more likely to be staged as localized than pediatric patients (62.5% vs 44.7%), to not receive any lymph node sampling (57.9% vs 16.2%), and to not receive any radiation treatment (74.3% vs 53.9%). Adults had a statistically worse overall survival (OS) than pediatric patients (5-year OS, 69% vs 88%, P<.001) despite the earlier tumor stage. When stratified by treatment era, the OS of all patients treated after 1981 was statistically higher than those treated before (5-year OS, 75% vs 89%, P<.001). Significant predictors of OS on univariate analysis for adults included treatment era, SEER stage, surgery, and radiation treatment. Significant predictors of OS on multivariate analysis of all patients included adult status (hazard ratio, 4.14; P<.001), treatment era, SEER stage, and surgery.

CONCLUSION

Adults in the SEER database had statistically worse OS than pediatric patients despite previous studies showing comparable outcome when treated on protocol. The worse outcome of SEER adults likely stems from incorrect diagnosis, inadequate staging and undertreatment. We recommend lymph node samplings for all adult Wilms' tumor patients and collaboration with pediatric oncologists.

Management of Wilms' tumor: NWTS vs SIOP

With the availability of several protocols in the management of Wilms' tumor, there is dilemma in the minds of the treating oncologists or pediatric onco-surgeons as to whether the child should receive upfront chemotherapy or should be operated upon primarily. It is necessary for us to understand why do we follow either of the protocols, NWTS which follows the upfront surgery principle or the SIOP which follows the upfront chemotherapy principle in all stages of the disease. While deciding which protocol to follow, it is imperative to know the pros and cons of the treatment strategies and also to study the outcome patterns in both the treatment regimes which is what this article highlights. In an attempt to compare all the differences in both the major protocols, it was realized that most of our patients in the Indian scenario present with advanced disease and thus poorer outcomes if intensive and appropriate treatment strategies are not utilized. Hence, it is imperative that we should study our own patients through the Indian Wilms' tumor study group and adopt the policies which improve the overall event free survival on a nationwide basis.

Wilms' tumor: An update

Wilms' tumor (WT) is the commonest pediatric renal tumor, predominantly seen in children less than five years of age. The majority of patients present with an abdominal lump and CT scan is the usual imaging modality for determining the extent of disease. With multimodality management, the results of treatment of WT have improved dramatically over the last 50 years. The treatment protocols have been devised and modified repeatedly depending on evidence from randomized trials by several cooperative groups - mainly National Wilms' Tumor Study Group (NWTSG) and the International Society of Pediatric Oncology (SIOP). The NWTSG recommends primary surgery followed by chemotherapy while SIOP advocates four weeks of chemotherapy prior to surgery. The regimen, dose and duration of chemotherapy have been repeatedly modified to reduce toxicity while maintaining efficacy. The role of radiation therapy has also been customized. Most centers have reported excellent survival rates with the modern day treatment protocols, except in patients with an unfavorable histology. The results of treatment of relapsed WT have also improved with newer drugs and combinations being used for the same.

The management of synchronous bilateral Wilms tumor: a report from the National Wilms Tumor Study Group

OBJECTIVE

To provide guidelines for future trials, we reviewed the outcomes of children with synchronous bilateral Wilms tumors (BWT) treated on National Wilms Tumor Study-4 (NWTS-4).

METHODS

NWTS-4 enrolled 3335 patients including 188 patients with BWT (5.6%). Treatment and outcome data were collected.

RESULTS

Among 188 BWT patients registered with NWTS-4, 195 kidneys in 123 patients had initial open biopsy, 44 kidneys in 31 patients had needle biopsies. Although pre-resection chemotherapy was recommended, 87 kidneys in 83 patients were managed with primary resection: Complete nephrectomy 48 in 48 patients, 31 partial/wedge nephrectomies in 27 patients, enucleations 8 in 8 patients. No initial surgery was performed in 45 kidneys in 43 patients, 5 kidneys in 3 patients not coded. Anaplasia was diagnosed after completion of the initial course of chemotherapy in 14 patients (initial surgical procedure: 9 open biopsies, 4 needle biopsies, 1 partial nephrectomy). The average number of days from the start of chemotherapy to diagnosis of anaplasia was 390 (range 44-1925 days). Relapse or progression of disease occurred in 54 children. End stage renal failure occurred in 23 children, 6 of whom had bilateral nephrectomies. The 8 year event free survival for BWT with favorable histology was 74%, and overall survival was 89%; whereas the event free survival for BWT with unfavorable histology was 40%, overall survival was 45%.

CONCLUSION

The current analysis of patients with BWT treated on NWTS-4 shows that preservation of renal parenchyma is possible in many patients after initial preoperative chemotherapy. The incidence of end-stage renal disease remains significantly higher in children with BWT. Future studies are warranted to address the need for earlier biopsy in nonresponsive tumors and earlier definitive surgery to recognize unfavorable histology in these high-risk patients.

P-glycoprotein expression, tumor weight, age, and relapse in patients with stage I and II favorable-histology Wilms' tumor

Fifteen percent of patients with Wilms' tumor (WT) experience relapse. It has been suggested that weight and age may affect the chances of relapse. Few studies have investigated the role, if any, between P-glycoprotein (P-gp) and relapse. The authors assessed the prognostic value of tumor weight and age at diagnosis and asked whether some other potential biological markers, specifically P-gp protein expression, had a prognostic value in favorable-histology WT. No association between age and relapse could be found. Patients with tumor weight ≥550 g were 6 times more likely to relapse, whereas P-gp expression was positive in 18/40 (45%) of the patients, of which 10/12 (83.3%) relapsed and 8/28 (28.6%) did not. Further studies are necessary to elucidate whether or not P-gp is related to relapse in patients with histologically favorable Wilms' tumor. If confirmed, the protein may be used in the future as a target for new drugs and treatments for this group of patients.

Treatment including anthracyclines versus treatment not including anthracyclines for childhood cancer

BACKGROUND

One of the most important adverse effects of anthracyclines is cardiotoxicity. A well-informed decision on the use of anthracyclines in the treatment of childhood cancers should be based on evidence regarding both antitumour efficacy and cardiotoxicity.

OBJECTIVES

To compare antitumour efficacy of treatment including or not including anthracyclines in children with childhood cancer.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2010, Issue 2), MEDLINE (1966 to March 2010) and EMBASE (1980 to March 2010). In addition, we searched reference lists of relevant articles, conference proceedings and ongoing trials databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing treatment of any type of childhood cancer with and without anthracyclines and reporting outcomes concerning antitumour efficacy.

DATA COLLECTION AND ANALYSIS

Two reviewers independently performed the study selection, risk of bias assessment and data extraction.

MAIN RESULTS

We identified RCTs for six types of tumour: acute lymphoblastic leukaemia (ALL) (three trials; 912 children), Wilms' tumour (one trial; 316 children), rhabdomyosarcoma/undifferentiated sarcoma (one trial; 413 children), Ewing's sarcoma (one trial; 94 children), non-Hodgkin lymphoma (one trial; 284 children) and hepatoblastoma (one trial; 255 children). All studies had methodological limitations. For ALL no evidence of a significant difference in antitumour efficacy was identified in the meta-analyses, but in most individual studies there was a suggestion of better antitumour efficacy in patients treated with anthracyclines. For both Wilms' tumour and Ewing's sarcoma a significant difference in event-free and overall survival in favour of treatment with anthracyclines was identified, although for Wilms' tumour the significant difference in overall survival disappears with long-term follow-up. For rhabdomyosarcoma/undifferentiated sarcoma, non-Hodgkin lymphoma and hepatoblastoma no difference in antitumour efficacy between the treatment groups was identified. Clinical cardiotoxicity was evaluated in three RCTs: no significant difference between both treatment groups was identified, but in all individual studies there was a suggestion of a lower rate of clinical cardiotoxicity in patients who did not receive anthracyclines. None of the studies evaluated asymptomatic cardiac dysfunction. For other childhood cancers no RCTs were identified.

AUTHORS' CONCLUSIONS

At the moment no evidence from RCTs is available which underscores the use of anthracyclines in ALL. However, "no evidence of effect", as identified in this review, is not the same as "evidence of no effect". For Wilms' tumour, rhabdomyosarcoma/undifferentiated sarcoma, Ewing's sarcoma, non-Hodgkin lymphoma and hepatoblastoma only one RCT was available and, therefore, no definitive conclusions can be made about the antitumour efficacy of treatment with or without anthracyclines in these tumours. For other childhood cancers no RCTs were identified and therefore, no conclusions can be made about the antitumour efficacy of treatment with or without anthracyclines in these tumours.

Secondary malignant neoplasms after Wilms tumor: an international collaborative study

A combined cohort of 8,884 North American, 2,893 British and 1,574 Nordic subjects with Wilms tumor (WT) diagnosed before 15 years of age during 1960-2004 was established to determine the risk of secondary malignant neoplasms (SMN). After 169,641 person-years (PY) of observation through 2005, 174 solid tumors (exclusive of basal cell carcinomas) and 28 leukemias were ascertained in 195 subjects. Median survival time after a solid SMN diagnosis 5 years or more from WT was 11 years; it was 10 months for all leukemia. Age-specific incidence of secondary solid tumors increased from approximately 1 case per 1,000 PY at age 15 to 5 cases per 1,000 PY at age 40. The cumulative incidence of solid tumors at age 40 for subjects who survived free of SMNs to age 15 was 6.7%. Leukemia risk, by contrast, was highest during the first 5 years after WT diagnosis. Standardized incidence ratios (SIRs) for solid tumors and leukemias were 5.1 and 5.0, respectively. Results for solid tumors for the 3 geographic areas were remarkably consistent; statistical tests for differences in incidence rates and SIRs were all negative. Age-specific incidence rates and SIRs for solid tumors were lower for patients whose WT was diagnosed after 1980, although the trends with decade of diagnosis were not statistically significant. Incidence rates and SIRs for leukemia were highest among those diagnosed after 1990 (p-trend = 0.003). These trends may reflect the decreasing use of radiation therapy and increasing intensity of chemotherapy in modern protocols for treatment of WT.

Decision analysis to compare treatment strategies for Stage I/favorable histology Wilms tumor

BACKGROUND

Decision analysis was used to clarify differences in survival and complication rates comparing surgery alone versus surgery plus chemotherapy for Stage I, favorable histology Wilms tumor patients.

PROCEDURE

A state transition model was used to simulate treatment with nephrectomy-only, nephrectomy with adjuvant vincristine (VCR) or with vincristine plus dactinomcyin (NWTS Regimen EE4A). Rates of relapse and complications of therapy were obtained from the literature. In sensitivity analysis, the model was probed for the value(s) at which the treatment of choice changes.

RESULTS

The overall survival (OS) is essentially the same for patients treated with any of the three strategies (OS(Nephrectomy) = 98.8%; OS(EE4A) = 98.8%; OS(VCR) = 98.6%). Rates of serious long-term complications in the surviving population are also similar across treatment strategies (nephrectomy = 1.4%; VCR = 1.2%; EE4A = 0.3%). Both the progression and salvage rates after nephrectomy-only would have to be much worse than expected for nephrectomy-only to be an unacceptable strategy.

CONCLUSIONS

The differences in overall survival and rates of long-term complications between the three different initial strategies were negligible in the model. Based on this analysis, it was decided by the Children's Oncology Group that it was acceptable to continue to include nephrectomy without adjuvant chemotherapy as an experimental arm of the low risk Wilms tumor protocol with stringent eligibility criteria and close follow-up. Decision analysis can have a role in clinical trial design by making the tradeoffs between strategies more explicit. The robustness of these conclusions can be tested by widely varying the underlying assumptions.

Pregnancy outcome after treatment for Wilms tumor: a report from the national Wilms tumor long-term follow-up study

PURPOSE

This study was undertaken to evaluate the effect of prior treatment with radiation therapy or chemotherapy for unilateral Wilms tumor (WT) diagnosed during childhood on pregnancy complications, birth weight, and the frequency of congenital malformations in live-born offspring.

PATIENTS AND METHODS

We reviewed pregnancy outcomes among female survivors and partners of male survivors of WT treated on National Wilms Tumor Studies 1, 2, 3, and 4 by using a maternal questionnaire and a review of both maternal and offspring medical records.

RESULTS

We received reports of 1,021 pregnancies with duration of 20 weeks or longer, including 955 live-born singletons, for whom 700 sets of maternal and offspring medical records were reviewed. Rates of hypertension complicating pregnancy (International Classification of Diseases [ICD] code 642), early or threatened labor (ICD-644) and malposition of the fetus (ICD-652) increased with increasing radiation dose in female patients. The percentages of offspring weighing less than 2,500 g at birth and of those having less than 37 weeks of gestation also increased with dose. There was no significant trend with radiation dose in the number of congenital anomalies recorded in offspring of female patients.

CONCLUSION

Women who receive flank radiation therapy as part of the treatment for unilateral WT are at increased risk of hypertension complicating pregnancy, fetal malposition, and premature labor. The offspring of these women are at risk for low birth weight and premature (ie, < 37 weeks gestation) birth. These risks must be considered in the obstetrical management of female survivors of WT.

Outcomes of children with favorable histology wilms tumor and peritoneal implants treated in National Wilms Tumor Studies-4 and -5

PURPOSE

There are no published reports on the optimal management and survival rates of children with Wilms tumor (WT) and peritoneal implants (PIs).

METHODS AND MATERIALS

Among favorable histology WT patients enrolled in the National Wilms Tumor Study (NWTS)-4 and NWTS-5, 57 children had PIs at the time of nephrectomy. The median age was 3 years 5 months (range, 3 months to 14 years). The majority of children (42 of 57 [74%)] had Stage III tumors; 15 had Stage IV disease. All patients received multimodality therapy. Of 56 children who underwent primary surgery, 48 (84%) had gross total resection of all tumors. All patients received 3-drug chemotherapy with vincristine, dactinomycin, and doxorubicin. Whole-abdomen radiotherapy (RT) was used in 47 patients (82%), and in 50 patients (88%) the RT dose was 10.5 Gy.

RESULTS

After a median follow-up of 7.5 years, the overall abdominal and systemic tumor control rates were 97% and 93%, respectively. A comparative analysis between children with PIs and those without PIs showed no significant differences in the clinical characteristics between the two groups. The 5-year event-free survival rates with and without PIs were 90% (95% confidence interval, 78-96%) and 83% (95% confidence interval, 81-85%) respectively (p = 0.20).

CONCLUSIONS

Multimodality therapy with surgery, whole-abdomen RT, and three-drug chemotherapy delivered according to the NWTS-4 and -5 protocols resulted in excellent abdominal and systemic tumor control rates. All children should be monitored in long-term surveillance programs for the early detection and management of therapy-related toxicities.

Outcomes for children and adolescents with cancer: challenges for the twenty-first century

PURPOSE

This report provides an overview of current childhood cancer statistics to facilitate analysis of the impact of past research discoveries on outcome and provide essential information for prioritizing future research directions.

METHODS

Incidence and survival data for childhood cancers came from the Surveillance, Epidemiology, and End Results 9 (SEER 9) registries, and mortality data were based on deaths in the United States that were reported by states to the Centers for Disease Control and Prevention by underlying cause.

RESULTS

Childhood cancer incidence rates increased significantly from 1975 through 2006, with increasing rates for acute lymphoblastic leukemia being most notable. Childhood cancer mortality rates declined by more than 50% between 1975 and 2006. For leukemias and lymphomas, significantly decreasing mortality rates were observed throughout the 32-year period, though the rate of decline slowed somewhat after 1998. For remaining childhood cancers, significantly decreasing mortality rates were observed from 1975 to 1996, with stable rates from 1996 through 2006. Increased survival rates were observed for all categories of childhood cancers studied, with the extent and temporal pace of the increases varying by diagnosis.

CONCLUSION

When 1975 age-specific death rates for children are used as a baseline, approximately 38,000 childhood malignant cancer deaths were averted in the United States from 1975 through 2006 as a result of more effective treatments identified and applied during this period. Continued success in reducing childhood cancer mortality will require new treatment paradigms building on an increased understanding of the molecular processes that promote growth and survival of specific childhood cancers.

Nodal evaluation in Wilms' tumors: analysis of the national cancer data base

OBJECTIVE

We used a large US clinical cancer registry to assess nodal evaluation performance in children with Wilms' Tumors (WT), to determined factors associated with nodal evaluation, and to define the prognostic importance of nodal status.

SUMMARY BACKGROUND DATA

Lymph node assessment remains a part of accurate staging and helps determine therapy for patients with WT. Lack of nodal assessment has been noted but not well studied.

METHODS

Patients (0-18 years) with WT from the National Cancer Data Base (1985-2001) were assessed for nodal evaluation. Logistic regression was used to identify factors associated with the likelihood of lymph node evaluation. Survival was estimated using the Kaplan-Meier method. Cox regression was used to estimate the risk of mortality.

RESULTS

Of 3593 patients, 1510 (42%) had no lymph nodes evaluated by pathology and reported to the National Cancer Data Base. Of 2083 patients who had lymph nodes assessed, 535 (25.7%) had positive nodes. Patients age 2 years or younger, with larger tumor size, and treated at a higher volume center were more likely to have nodes assessed (P < 0.01). Patients who had nodes evaluated had a better 5-year survival compared with those who did not have nodes evaluated (92.2% vs. 88.1%, P < 0.001). In Cox regression, nodal metastases (P < 0.001; HR: 2.2, CI: 1.6-3.0) were associated with increased risk of death after adjusting for patient, tumor, and hospital characteristics.

CONCLUSIONS

Many patients do not have lymph nodes evaluated during WT resection. Opportunities exist for improved staging and possibly survival in patients with WT through better nodal assessment.

Intraoperative spillage of favorable histology wilms tumor cells: influence of irradiation and chemotherapy regimens on abdominal recurrence. A report from the National Wilms Tumor Study Group

PURPOSE

We undertook this study to determine (1) the frequency with which spilled tumor cells of favorable histology produced intra-abdominal disease in patients treated with differing chemotherapy regimens and abdominal radiation therapy (RT) and (2) the patterns of relapse and outcomes in such patients.

METHODS AND MATERIALS

The influence of RT dose (0, 10, and 20 Gy), RT fields (flank, whole abdomen), and chemotherapy with dactinomycin and vincristine (2 drugs) vs. added doxorubicin (three drugs) on intra-abdominal tumor recurrence rates was analyzed by logistic regression in 450 patients. Each patient was considered at risk for two types of failure: flank and subdiaphragmatic beyond-flank recurrence, with the correlation between the two outcomes accounted for in the analyses.

RESULTS

The crude odds ratio for the risk of recurrence relative to no RT was 0.35 (0.15-0.78) for 10Gy and 0.08 (0.01-0.58) for 20Gy. The odds ratio for the risk of recurrence for doxorubicin to two drugs after adjusting for RT was not significant. For Stage II patients (NWTS-4), the 8-year event rates with and without spillage, respectively, were 79% and 87% for relapse-free survival (p = 0.07) and 90% and 95% for overall survival (p = 0.04).

CONCLUSIONS

Irradiation (10 Gy or 20 Gy) reduced abdominal tumor recurrence rates after tumor spillage. Tumor spillage in Stage II patients reduced relapse-free survival and overall survival, but only the latter was of statistical significance. These data provide a basis for assessing the risks vs. benefits when considering treatment for children with favorable histology Wilms tumor and surgical spillage.

Portal hypertension in children with Wilms' tumor: a report from the National Wilms' Tumor Study Group

PURPOSE

This analysis was undertaken to determine the cumulative risk of and risk factors for portal hypertension (PHTN) in patients with Wilms' tumor (WT).

METHODS AND MATERIALS

Medical records were reviewed to identify cases of PHTN identified with late liver/spleen/gastric toxicities in a cohort of 5,195 patients treated with National Wilms' Tumor Studies (NWTS) protocols 1 to 4. A nested case control study (5 controls/case) was conducted to determine relationships among doxorubicin, radiation therapy (RT) dose to the liver, patient gender, and PHTN. Conditional logistic regression was used to estimate adjusted hazard ratios (HR) of PHTN associated with these factors.

RESULTS

Cumulative risk of PHTN at 6 years from WT diagnosis was 0.7% for patients with right-sided tumors vs. 0.1% for those with left-sided tumors (p = 0.002). Seventeen of 19 cases were evaluable for RT. The majority of cases (16/17 [94%]) received right-flank RT either alone or as part of whole-abdomen RT and received >15 Gy to the liver. Fifteen of 17 (88%) patients received a higher dose to the liver than they would have with modern WT protocols. Controlling for RT dose, the HR was 3.0 for patients who received doxorubicin (p = 0.32) and 2.8 for females (p = 0.15). Controlling for doxorubicin, the 95% lower confidence bound on the HR associating PHTN with a minimum liver RT dose of >15 Gy vs. <or=15 Gy was 2.5 (p = 0.001); it was 2.4 for a maximum liver dose of >15 Gy vs. <or=15 Gy (p = 0.001).

CONCLUSIONS

There was a strong association between higher doses of liver RT (>15 Gy) and the development of PHTN among WT patients.

Wilms' tumor

PURPOSE OF REVIEW

Wilms' tumor accounts for nearly 6% of all pediatric cancers and more than 95% of all kidney tumors in children. Fortunately, survival for patients with Wilms' tumor is generally excellent. This review will outline the results of prior clinical trials that have led to this excellent outcome and how information gleaned from these trials has led to the development of the current series of clinical trials for the management of children with Wilms' tumor.

RECENT FINDINGS

Tumor stage and histologic subtype have long been recognized as important prognostic factors in Wilms' tumor. More recent evidence suggests that, in certain instances, patient age, tumor size, response to therapy, and genetic abnormalities, specifically the loss of genetic material on chromosomes 1p and 16q, provide additional prognostic information. These factors have, therefore, been incorporated into a new risk stratification system that is currently being used to assign patients with Wilms' tumor to specific protocol-based therapies.

SUMMARY

Survival for patients with Wilms' tumor when considered as a whole, once less than 30%, is currently greater than 90%, with this dramatic improvement being due, in part, to the systematic manner in which the approach to therapy has evolved. Further refinement in therapy is being undertaken, with the current trials aiming to maintain the excellent survival for children being treated for Wilms' tumor, while minimizing therapy-related toxicity.

Early and late mortality after diagnosis of wilms tumor

PURPOSE

To assess rates and causes of mortality in patients with Wilms tumor (WT).

METHODS

Through 2002, 6,185 patients enrolled onto the National Wilms Tumor Study between 1969 and 1995 were actively observed. Deaths were classified on the basis of medical records as the result of original disease, late effects (including second malignant neoplasms [SMNs], cardiac causes, pulmonary disease, and renal failure), or other causes. Standardized mortality ratios (SMRs) and Cox regression were used to assess the effects of sex, age, and calendar period of diagnosis on mortality.

RESULTS

Within 5 years of WT diagnosis, 819 deaths occurred, and 159 deaths occurred among 4,972 known 5-year survivors. The SMR was 24.3 (95% CI, 22.6 to 26.0) for the first 5 years, was 12.6 (95% CI, 10.0 to 15.7) for the next 5 years, and remained greater than 3.0 thereafter. For deaths in the first 5 years, the mortality risk decreased by 5-year calendar period of diagnosis (rate ratio [RR] = 0.78 per period). No such trend occurred for later deaths. Among 5-year survivors, 62 deaths were attributed to late effects of treatment or disease, including 27 to SMNs. A trend of decreased risk with calendar period of diagnosis was observed for late-effects mortality (RR = 0.86; 95% CI, 0.67 to 1.10) and for SMN mortality (RR = 0.82; 95% CI, 0.55 to 1.21).

CONCLUSION

Although the survival outlook for WT patients has improved greatly over time, survivors remain at elevated risk for death many years after their original diagnosis.

Current management of Wilms' tumor in children

PURPOSE

Wilms' tumor is the most common renal tumor in children. Outcomes have improved dramatically over the past few decades, but important treatment questions remain. These include the role of molecular biologic markers in stratifying patients for therapy or targeting tumors for treatment. We present a summary of these advances and outline the current treatment of Wilm's tumor.

MATERIALS AND METHODS

The medical literature and results of all cooperative group studies reporting treatment of children with Wilms' tumor were reviewed.

RESULTS

Overall survival exceeds 90% for most patients with nephroblastoma. However, outcomes for patients with rhabdoid tumors and diffuse anaplasia remain poor. The role of renal sparing surgery in patients with bilateral tumors is clear, but for children with unilateral tumors it continues to be defined.

CONCLUSIONS

Current protocols conducted by pediatric oncology groups are beginning to incorporate biologic features to stratify patients for therapy. Treatment strategies continue to focus on limiting late effects of treatment while maintaining an excellent survival. New therapies are needed to treat the high-risk patients who continue to have high relapse and mortality rates.

Treatment including anthracyclines versus treatment not including anthracyclines for childhood cancer

BACKGROUND

One of the most important adverse effects of anthracyclines is cardiotoxicity. A well-informed decision on the use of anthracyclines in the treatment of different types of childhood cancer should be based on the available evidence on both antitumour efficacy and cardiotoxicity.

OBJECTIVES

To compare antitumour efficacy of treatment including or not including anthracyclines in children with childhood cancer.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2006, issue 4), MEDLINE (1966 to January 2007) and EMBASE (1980 to January 2007). In addition, we searched reference lists of relevant articles, conference proceedings and ongoing trials databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing treatment of any type of childhood cancer with and without anthracyclines and reporting outcomes concerning antitumour efficacy.

DATA COLLECTION AND ANALYSIS

Two reviewers independently performed the study selection, quality assessment and data-extraction.

MAIN RESULTS

We identified RCTs for 5 types of tumour: acute lymphoblastic leukaemia (ALL) (n=3; 912 children), Wilms' tumour (n=1; 316 children), rhabdomyosarcoma/undifferentiated sarcoma (n=1; 413 children), Ewing's sarcoma (n=1; 94 children), and non-Hodgkin lymphoma (n=1; 284 children). All studies had methodological limitations. For ALL no evidence of a significant difference in antitumour efficacy was identified in the meta-analyses, but in most individual studies there was a suggestion of better antitumour efficacy in patients treated with anthracyclines. For both Wilms' tumour and Ewing's sarcoma a significant difference in survival in favour of treatment with anthracyclines was identified. The hazard ratios for overall and event-free survival in Wilms' tumour were 1.85 (95% CI 1.09 to 3.15) and 2.21 (95% CI 1.44 to 3.40), respectively. For patients with Ewing's sarcoma only descriptive results were available (P = 0.02 for overall survival and P = 0.01 for event-free survival). For both rhabdomyosarcoma/undifferentiated sarcoma and non-Hodgkin lymphoma no difference in antitumour efficacy between the treatment groups was identified. Clinical cardiotoxicity was evaluated in 3 RCTs. No significant difference between both treatment groups was identified, but in all individual studies there was a suggestion of a lower rate of clinical cardiotoxicity in patients who did not receive anthracyclines. None of the studies evaluated asymptomatic cardiac dysfunction. For other childhood cancers no RCTs were identified.

AUTHORS' CONCLUSIONS

At the moment no evidence from RCTs is available which underscores the use of anthracyclines in ALL. However, it should be noted that "no evidence of effect", as identified in this review, is not the same as "evidence of no effect". For Wilms' tumour, rhabdomyosarcoma/undifferentiated sarcoma, Ewing's sarcoma, and non-Hodgkin lymphoma only 1 RCT was available and therefore, no definitive conclusions can be made about the antitumour efficacy of treatment with or without anthracyclines in these tumours. For other childhood cancers no RCTs were identified and therefore, no conclusions can be made about the antitumour efficacy of treatment with or without anthracyclines in these tumours. More high quality research is needed.

The prognostic relevance of preoperative transcatheter arterial chemoembolization (TACE) and PCNA/VEGF expression in patients with Wilms' tumour

BACKGROUND

Wilms' tumour is the most frequent renal tumour in children. Based on the SIOP strategy, children with Wilms' tumour may benefit from preoperative chemotherapy, but few publications address the effect of preoperative transcatheter arterial chemoembolization (TACE) on patients with Wilms' tumours. The aims of this study were to investigate the prognostic relevance of preoperative TACE followed by tumour resection, proliferating cell nuclear antigen (PCNA) and vascular endothelial growth factor (VEGF) expression in patients with Wilms' tumours.

MATERIALS AND METHODS

Two therapeutic strategies including tumour resection only and TACE, followed by tumour resection were conducted in a cohort of 44 patients with Wilms' tumours. Clinical and follow-up data was analysed. Immunohistochemistry staining was used to explore PCNA and VEGF expression in the Wilms' tumour.

RESULTS

Two years tumour-free survival of the patients in the TACE group was significantly higher than that of the patients in the control group (P < 0.001) and recurrence and cases of death within one year in the TACE group was markedly lower than that in the control group (P < 0.001). Fifty-five percent of patients in the control group were PCNA-positive vs. 4.17% of patients in the TACE group (P < 0.001). Fifty percent of patients in the control group were VEGF-positive vs. 29.17% of patients in the TACE group (P > 0.05).

CONCLUSIONS

Patients with Wilms' tumours benefited from preoperative TACE treatment. PCNA expression was significantly lower in patients in the TACE group than those in the control group. There was no significant difference on VEGF expression between the patients in TACE and control groups.

Progress in childhood cancer: 50 years of research collaboration, a report from the Children's Oncology Group

The Children's Oncology Group (COG) recently celebrated the milestone of 50 years of pediatric clinical trials and collaborative research in oncology. Our group had its origins in the four legacy pediatric clinical trials groups: the Children's Cancer Group (CCG), the Pediatric Oncology Group (POG), the National Wilms' Tumor Study Group (NWTS), and the Intergroup Rhabdomyosarcoma Study Group (IRSG), which merged in 2000 to form the COG. Over the last 50 years, the survival rates for childhood cancer have risen from 10% to almost 80%. Outcome in acute lymphoblastic leukemia (ALL) has gone from a 6-month median survival to an 80% overall cure rate. We have modified therapies in most major diseases to induce remission with the fewest long-term sequelae. Here we look back on our advances but also look forward to the next 50 years, which will produce even more successful treatments that will be tailored to the specific patient, translating the tools of molecular genetics. Experience has clearly proven that everything we know about the diagnosis and management of childhood cancer is a result of research and the dramatic historical decrease in mortality from childhood cancer is directly related to cooperative group clinical research.

Current and emerging chemotherapy treatment strategies for Wilms tumor in North America

Wilms tumor is the most common primary renal malignancy occurring in childhood. Approximately 500 children are diagnosed with Wilms tumor annually in the US alone, most of whom are aged <5 years. Several prognostic factors have been identified, including stage of disease, tumor histology, patient age, tumor weight, and tumor-specific loss of heterozygosity for chromosomes 1p and 16q. During the period from 1969 to 2002, the National Wilms Tumor Study Group coordinated five multicenter Wilms tumor studies. The overall survival rate for Wilms tumor has risen to >90% for patients with tumors of favorable histology. However, the treatment of patients with Wilms tumor with anaplastic histology remains challenging. The optimal treatment strategies for Wilms tumor in relapse will be studied via international collaboration in the near future. Goals of emerging studies include minimizing toxicity while maintaining the outstanding cure rates for patients with a good prognosis and, through advancing biologic understanding and developing novel therapeutic approaches, improving the prognosis for those patients in whom effective cure of their disease continues to elude physicians.

Treatment of Wilms tumor relapsing after initial treatment with vincristine, actinomycin D, and doxorubicin. A report from the National Wilms Tumor Study Group

OBJECTIVE

We evaluated the use of alternating cycles of cyclophosphamide/etoposide and carboplatin/etoposide in children entered on National Wilms Tumor Study (NWTS)-5 who were diagnosed between August 1, 1995 and May 31, 2002 and who relapsed after chemotherapy with vincristine, actinomycin D, and doxorubicin (VAD) and radiation therapy (DD-4A).

PATIENTS AND METHODS

One hundred three patients who relapsed or had progressive disease after initial VAD chemotherapy and radiation therapy were registered on stratum C of the NWTS-5 Relapse protocol. Twelve patients were not evaluable: five due to insufficient data, six due to major protocol violations, and one for refusal of therapy. Among the 91 remaining patients, 14 with stage V Wilms tumor (WT), 1 with contralateral relapse, and 16 who did not achieve a complete response (CR) to the initial three-drug chemotherapy were not included in this analysis. Relapse treatment included alternating courses of the drug pairs cyclophosphamide/etoposide and carboplatin/etoposide, surgery, and radiation therapy.

RESULTS

The outcomes of 60 patients were analyzed. The lung was the only site of relapse for 33 patients; other sites of relapse included the operative bed, the abdomen, and liver. Four-year event-free survival (EFS) and overall survival (OS) were 42.3 and 48.0% respectively for all patients and were 48.9 and 52.8% for those who relapsed in the lungs only. Thrombocytopenia was the most frequent toxicity.

CONCLUSION

These results demonstrate that approximately one-half of children with unilateral WT who relapse after initial treatment with VAD and radiation therapy can be successfully retreated.

Wilms tumour: prognostic factors, staging, therapy and late effects

Wilms tumour is the most common malignant renal tumour in children. Dramatic improvements in survival have occurred as the result of advances in anaesthetic and surgical management, irradiation and chemotherapy. Current therapies are based on trials and studies primarily conducted by large multi-institutional cooperatives including the Société Internationale d'Oncologie Pédiatrique (SIOP) and the Children's Oncology Group (COG). The primary goals are to treat patients according to well-defined risk groups in order to achieve the highest cure rates, to decrease the frequency and intensity of acute and late toxicity and to minimize the cost of therapy. The SIOP trials and studies largely focus on the issue of preoperative therapy, whereas the COG trials and studies start with primary surgery. This paper reviews prognostic factors and staging systems for Wilms tumour and its current treatment with surgery and chemotherapy. Surgery remains a crucial part of treatment for nephroblastoma, providing local primary tumour control and adequate staging and possibly controlling the metastatic spread and central vascular extension of the disease. Partial nephrectomy, when technically feasible, seems reasonable not only in those with bilateral disease but also in those with unilateral disease where the patient has urological disorders or syndromes predisposing to malignancy. Partial nephrectomy, however, is frequently not sufficient for an anaplastic variant of tumour. The late effects for Wilms tumour and its treatment are also reviewed. The treatment of Wilms tumour has been a success story, and currently in excess of 80% of children diagnosed with Wilms tumour can look forward to long-term survival, with less than 20% experiencing serious morbidity at 20 years from diagnosis. The late complications are a consequence of the type and intensity of treatment required, which in turn reflects the nature and extent of the original tumour. Continual international trial development and participation will improve matching of treatment needs with prognosis, reducing long-term complications in the majority. The advent of molecular markers of disease severity and improved functional imaging might help.

The National Wilms Tumor Study: a 40 year perspective

The National Wilms Tumor Study (NWTS) was the first pediatric intergroup clinical research unit in North America. It was thus able to collect data concerning children with malignant kidney tumors from each of the then-extant childhood cancer cooperative study groups. Enough patients-about 350 per year-could thus be gathered to study the nature and clinical characteristics of the various kidney malignant tumors of childhood. It also enabled randomized trials of comparative treatment regimens, patients stratified following stipulated risk criteria. The result has been a steadily increasing two-year survival rate to the 90% level while at the same time modulating the intensity of therapy according to well-defined needs. For example, routine post-operative radiation therapy, damaging to normal as well as neoplastic tissues, has been largely eliminated. The proportion of patients given doxorubicin, a cardiotoxic drug, also has been curtailed. These two therapies are now restricted to the 30% of patients who have more advanced or more aggressive disease. All this has been driven to meet the challenge inherent in the motto of pediatric oncology: "Cure is not enough"; that is, the cured child of to-day must not become the chronically ill adult of tomorrow, suffering from the delayed complications secondary to unnecessary, toxic therapies.

Controversies in the management of Wilms tumour - immediate nephrectomy or delayed nephrectomy?

Wilms tumour is the paradigm for the treatment of a malignant solid tumour of children and adolescents. Dramatic improvements in survival have occurred as the result of advances in anaesthetic and surgical management, radiation therapy technique and the availability of several very effective chemotherapeutic agents. Despite these successes, controversy exists regarding the initial management of children with unilateral, favourable histology Wilms tumour. Two different approaches have been recommended by different investigators - immediate nephrectomy or pre-nephrectomy chemotherapy followed by delayed nephrectomy. The results of randomised trials will be reviewed and the benefits and risks of each approach discussed.

Mortality ascertainment of participants in the National Wilms Tumor Study using the National Death Index: comparison of active and passive follow-up results

Long term studies of childhood cancer survivors are hampered by difficulties in tracking young adult participants. After performing a National Death Index (NDI) search we sought to identify which factors best predicted a match among known decedents from the National Wilms Tumor Study (NWTS) and to determine if record linkage could substitute for missing follow-up in a cohort of NWTS survivors. To our knowledge, this is the first study to compare passive mortality follow-up using the NDI to active follow-up of a childhood and young adult population. Records for 984 known decedents and 3,406 subjects whose January 1, 2002 vital status was unknown were sent to the NDI in June 2003. In April 2005 NWTS follow-up records were used to reassess January 1, 2002 vital status. Matches were established for 709 of 789 known decedents (sensitivity 89.9%) with a date of death between 1979 and 2001, the calendar period covered by the NDI at the time of the search. No matches were identified among 1,052 subjects known to be alive in 2002 (specificity 100%). Factors associated with decreased sensitivity were an unknown social security number (sensitivity 87.8%), Hispanic ethnicity (76.4%) and foreign birth (56.5%). For 2,351 subjects with 2002 vital status unknown who had 13,166 pre 2002 person-years of missing observation, only 18 deaths were ascertained by the NDI whereas 79.3 were expected based on NWTS mortality data. Mortality analyses based strictly on NDI search results and those based on NWTS follow-up augmented with NDI search results yielded inflated estimates of the 15 year survival rate when compared with estimates based on NWTS active follow-up. Match rates were comparable to those observed in adult populations. Since the same selection factors were likely associated with NDI failure to match and NWTS loss to follow-up, use of the NDI to fill in missing follow-up data appears unwarranted.

An update on the management of Wilms' tumour

AIMS

To review the management of Wilms' tumour.

METHODS

A search of the literature was performed using the PubMed database (1966 to May 2006) with the search terms 'Wilms' and either 'tumour/tumor' or 'cancer' or 'carcinoma'. This was augmented by manual searches of publications.

FINDINGS

The success of clinical trials in Wilms' tumour patients over the past 30 years has led to an overall survival of 85% and the introduction of less aggressive chemotherapeutic regimes for patients. Large randomised controlled trials have been published on the management of Wilms' tumour by various collaborative groups, including the National Wilms' Tumour Study Group (NWTSG) in North America and the Société Internationale d'Oncologie Pédiatrique (SIOP) plus the United Kingdom Children's Cancer Study Group (UKCCSG) in Europe.

CONCLUSIONS

Controversy exists as to the best approach to the management of these children with regard to neoadjuvant chemotherapy. Challenges remain in the identification of histological and molecular risk factors for the stratification of treatment intensity.

[Risk factors for intra- and postoperative complications in Wilms' tumor surgery]

BACKGROUND

Wilms' tumor is the most common renal tumor in childhood. Preoperative treatment is still under discussion. The aim of this study was to determine, using our own patient collective, the risk factors for and type of intraoperative complications which can occur. In addition, the influence of the surgical procedure and tumor size on the complications and survival rate was analyzed.

METHODS AND MATERIALS

A total of 66 patients with Wilms' tumor were retrospectively analyzed. Evaluation included histology, size of the primary tumor as well as neoadjuvant and adjuvant chemotherapy. The total survival rate over periods of 5 and 10 years postoperatively were analysed using Kaplan-Meier survival probabilities.

RESULTS

All patients underwent radical nephrectomy: 63 using the transperitoneal and three the lumbar approach. The tumors had a mean size of 9.8 cm (range 2.5-20.0). Twenty patients (30.3%) received neoadjuvant chemotherapy for tumor reduction, while 46 patients underwent surgery without preoperative chemotherapy. Complications occurred in eight patients (15.2%). In two, a the tumor ruptured under surgery, four patients developed an ileus and two suffered cardiac arrest. One patient had postoperative hypertonia and another an incisional hernia. All complications occurred with a tumor size >5 cm or in the patient group without neoadjuvant chemotherapy. The 10 year survival rate was 89.4%.

CONCLUSIONS

The risk of complications is associated with the local size of the primary tumor. Through tumor reduction, neoadjuvant chemotherapy influences the expression of the such complications. Transperitoneal tumor nephrectomy is the method of choice in surgery for Wilms' tumors.

Malignant renal tumours incidence and survival in European children (1978-1997): report from the Automated Childhood Cancer Information System project

More than 5000 cases of malignant renal tumour diagnosed in children under the age of 15 years during the period 1978-1997 in Europe, were extracted from the database of the Automated Childhood Cancer Information System (ACCIS). In 1988-1997 the age-standardised incidence rate of childhood renal tumours in Europe was 8.8 per million, with significant differences between regions. Wilms' tumour (WT, M-8960) accounted for 93% of renal tumours and about 7% were bilateral. The incidence rates of WT increased over the 20 years, by 0.7% per year. European 5-year survival for children diagnosed with WT in 1988-1997 was 85%, ranging from 73% in the East to 91% in the North. Patients in the age group 0-3 years at diagnosis had a more favourable prognosis (5-year survival 87%) than those diagnosed later (81%), P<0.0001. Patients with unilateral WT (n=2085) had better 5-year survival (85%) than 154 patients with bilateral tumours (76%), P=0.003. Five-year survival for 64 patients with clear cell sarcoma of kidney was 68%, for 43 patients with rhabdoid tumour of kidney it was 23%, and for 56 patients with renal cell carcinoma it was 87%. For combined European data, 5-year survival for WT increased from 73% in 1978-1982 to 87% in 1993-1997 and the increase was significant in three out of five regions (East, North and West). Further development and exploitation of the ACCIS database will benefit clinical management and aetiological studies.

The prognostic significance of angiogenesis and the effect of vascular endothelial growth factor on angiogenic process in Wilms’ tumour

AIMS

There is a subgroup of patients with Wilms' tumour (WT) having favourable clinicopathological features but adverse outcome. We aimed to investigate the prognostic significance of angiogenesis and whether it can be used for predicting which patients will fall into this category, and the possible role of vascular endothelial growth factor (VEGF) on angiogenesis in WT.

METHODS

Tumours in nephrectomy specimens from 63 WT patients were investigated for neovascularisation and VEGF expression by immunohistochemistry. The endothelial cells were highlighted by anti-CD34 and anti-CD31, and the microvessels in the hot-spots were counted. Correlations between the microvessel density (MVD), VEGF expression, clinicopathological features and prognosis were studied.

RESULTS

Among 21 patients with follow-up data, favourable histology was detected in 17, seven of which died of disease. Patients with highly vascular tumours showed significantly poorer prognosis than those with low vascular tumours. There was no significant relationship between angiogenesis and VEGF expression. VEGF immunostaining revealed various patterns in different components of WT.

CONCLUSIONS

We suggest that high MVD can be used as an indicator of poor prognosis with WT patients displaying favourable histology and there might be some additional growth factors other than VEGF which may also be responsible for angiogenesis in WTs.

Immediate nephrectomy versus preoperative chemotherapy in the management of non-metastatic Wilms' tumour: results of a randomised trial (UKW3) by the UK Children's Cancer Study Group

PURPOSE

To determine if patients receiving preoperative chemotherapy with vincristine and actinomycin D for non-metastatic Wilms' tumour have a more advantageous stage distribution and so need less treatment compared to patients who have immediate nephrectomy, without adversely affecting outcome.

METHODS

Between 1991 and 2001, a total of 205 patients with newly diagnosed non-metastatic renal tumours, of which 186 had Wilms' histologies, were randomly assigned either to immediate surgery or to 6 weeks preoperative chemotherapy and then delayed surgery. Both groups of children received postoperative chemotherapy according to tumour stage and histology determined at the time of nephrectomy.

RESULTS

There was a significant improvement in the stage distribution for patients with Wilms' histologies receiving delayed surgery compared to those having immediate nephrectomy (stage I: 65.2% versus 54.3%; stage II: 23.9% versus 14.9%; stage III: 9.8% versus 29.8%, chi2 test for trend=7.02, p=0.008). This improvement resulted in 20% fewer children receiving radiotherapy or doxorubicin yet event-free and overall survivals at 5 years of 79.6% and 89.0%, respectively, were similar in the two groups.

CONCLUSION

Six weeks of preoperative chemotherapy with vincristine and actinomycin D results in a significant shift towards a more advantageous stage distribution and hence reduction in therapy, while maintaining excellent event free and overall survival in children with non-metastatic Wilms' tumour. Around 20% of survivors were therefore spared the late-effects of doxorubicin or radiotherapy. Our results suggest that all children with non-metastatic Wilms' tumour should receive chemotherapy prior to tumour resection.

Radiation therapy for favorable histology Wilms tumor: prevention of flank recurrence did not improve survival on National Wilms Tumor Studies 3 and 4

PURPOSE

To determine whether radiation therapy (RT) of patients with Wilms tumor of favorable histology prevented flank recurrence and thereby improved the survival outcomes.

METHODS AND MATERIALS

Recurrence and mortality risks were compared among groups of patients with Stage I-IV/favorable histology Wilms tumor enrolled in the third (n = 1,640) and fourth (n = 2,066) National Wilms Tumor Study Group studies.

RESULTS

Proportions of patients with flank recurrence were 0 of 513 = 0.0% for 20 Gy, 12 of 805 = 1.5% for 10 Gy, and 44 of 2,388 = 1.8% for no flank RT (p trend = 0.001 adjusted for stage and doxorubicin); for intra-abdominal (including flank) recurrence they were 5 of 513 = 1.0%, 30 of 805 = 3.7%, and 58 of 2,388 = 2.4%, respectively (p trend = 0.02 adjusted). Survival percentages at 8 years after intra-abdominal recurrence were 0 of 5 = 0% for 20 Gy, 10 of 30 = 33% for 10 Gy, and 34 of 58 = 56% for no RT (p trend = 0.0001). NWTS-4 discontinued use of 20 Gy RT, and the 8-year flank recurrence risk increased to 2.1% from 1.0% on NWTS-3 (p = 0.013). However, event-free survival was unaltered (88% vs. 86%, p = 0.39), and overall survival was better (93.8% vs. 90.8%, p = 0.036) on NWTS-4.

CONCLUSIONS

Partly because of lower postrecurrence mortality among nonirradiated patients, prevention of flank recurrence by RT did not improve survival. It is important to evaluate entire treatment policies with regard to long-term outcomes.

Wilms' tumor: past, present and (possibly) future

Wilms' tumor is one of the successes of pediatric oncology, with an overall cure rate of over 85%, using relatively simple therapies. This excellent outcome has been the result of collaborative efforts among surgeons, pediatricians, pathologists and radiation oncologists. The results that have been achieved in children with Wilms' tumors support the strong value of the multidisciplinary team approach to cancer. The two largest cooperative groups that have studied the optimum treatment for Wilms' tumor are the National Wilms' Tumor Study group in North America and the International Society of Pediatric Oncology, involving European and other countries. The National Wilms' Tumor Study group recommends primary surgery before any adjuvant treatment, whereas the International Society of Pediatric Oncology trials are based on the use of preoperative chemotherapy. The debate on primary chemotherapy versus primary nephrectomy appears to have been overcome, in the sense that the advantages and disadvantages of these two diverse methods have emerged from large and well-performed clinical trials, and comparably low doses of anthracyclines and radiotherapy are now used. Challenges remain in identifying novel molecular, histological and clinical risk factors for stratification of treatment intensity. This could allow a safe reduction in therapy for patients known to have an excellent chance of cure with the current therapy, while identifying, at diagnosis, the minority of children at risk of relapse, who will necessitate more aggressive treatments. Another positive factor is the substantial progress that has been made in the cure for recurrent patients, with long-term survivals shifting from 30 to almost 60% in more recently treated patients with intensive-dose chemotherapy regimens. The combination of lower relapses and higher salvage rates translated into significantly improved overall survival for Wilms' tumor patients as a whole. This review covers current concepts on treatment strategies for Wilms' tumor, with an overview of the results and achievements of the important clinical trials.

Current therapy for Wilms' tumor

Wilms' tumor was the first solid malignancy in which the value of adjuvant chemotherapy was established. Multimodality treatment has resulted in a significant improvement in outcome from approximately 30% in the 1930s to more than 85% in the modern era. Although the National Wilms' Tumor Study Group and the International Society of Pediatric Oncology differ philosophically regarding the merits of preoperative chemotherapy, outcomes of patients treated with either up-front nephrectomy or preoperative chemotherapy have been excellent. The goal of current clinical trials is to reduce therapy for children with low-risk tumors, thereby avoiding acute and long-term toxicities. At the same time, current clinical trials seek to augment therapy for patients with high-risk Wilms' tumor, including those with bilateral, anaplastic, and recurrent favorable histology tumors.

Rhabdoid tumor of the kidney in the National Wilms' Tumor Study: age at diagnosis as a prognostic factor

PURPOSE

The objective of this study is to determine prognostic factors in rhabdoid tumor of the kidney (RTK), including both demographic and treatment variables.

PATIENTS AND METHODS

A total of 142 patients studied on National Wilms' Tumor Studies 1, 2, 3, 4, and 5 were analyzed. Patients were enrolled between the years 1969 and 2002. Variables examined included sex, age of diagnosis, tumor stage, presence of CNS lesions, as well as treatment variables, including the use of doxorubicin and/or radiotherapy (RT).

RESULTS

No survival differences were observed between males and females, between those treated with or without doxorubicin, or with or without RT. Patients with tumors of lower stage had an overall survival rate of 41.8%, whereas, tumors of higher stage were associated with a 15.9% survival (P < .001). A highly significant difference in survival was noted when patients were stratified according to age of diagnosis. Survival at 4 years in infants under 6 months of age at diagnosis was 8.8%, whereas, survival in patients 2 years of age or older was 41.1% (P < .0001). Stratification into intermediate age brackets demonstrated a strong correlation of increasing survival with increasing age at diagnosis. All patients with a CNS lesion, except one, died.

CONCLUSION

Age at diagnosis is a highly significant prognostic factor for survival of children with RTK. Infants have a dismal prognosis, whereas, older children have a more favorable outcome. Higher tumor stage and presence of a CNS lesion were both factors predictive of a poor survival rate.

Loss of heterozygosity for chromosomes 1p and 16q is an adverse prognostic factor in favorable-histology Wilms tumor: a report from the National Wilms Tumor Study Group

PURPOSE

To determine if tumor-specific loss of heterozygosity (LOH) for chromosomes 1p or 16q is associated with a poorer prognosis for children with favorable-histology (FH) Wilms tumor entered on the fifth National Wilms Tumor Study (NWTS-5).

PATIENTS AND METHODS

Between August 1995 and June 2002, 2,021 previously untreated children with FH or anaplastic Wilms tumor, clear-cell sarcoma of the kidney (CCSK) or malignant rhabdoid tumor of the kidney (RTK), were treated with stage- and histology-specific therapy. Their tumors were assayed for LOH for polymorphic DNA markers on chromosomes 1p and 16q. ResultsLOH for 1p or 16q was rarely observed in CCSK (n = 90) or RTK (n = 22). The relative risk (RR) of relapse for patients with FH stage I to IV tumors with LOH, stratified by stage, was 1.56 for LOH 1p (P = .01) and 1.49 for LOH 16q (P = .01), whereas the RR of death was 1.84 (P = .03) and 1.44 (P = .15), respectively. When the effects of LOH for both regions were considered jointly among patients with stage I to II FH disease, the risks of relapse and death were increased for LOH 1p only (RR = 2.2, P = .02 for relapse; RR = 4.0, P = .02 for death), for LOH 16q only (RR = 1.9, P = .01 and RR = 1.4, P = .60) and for LOH for both regions (RR = 2.9, P = .001 and RR = 4.3, P = .01) in comparison with patients with LOH at neither locus. The risks of relapse and death for patients with stage III to IV FH tumors were increased only with LOH for both regions (RR = 2.4, P = .01 and RR = 2.7, P = .04).

CONCLUSION

Tumor-specific LOH for both chromosomes 1p and 16q identifies a subset of FH Wilms tumor patients who have a significantly increased risk of relapse and death. LOH for these chromosomal regions can now be used as an independent prognostic factor together with disease stage to target intensity of treatment to risk of treatment failure.