[Treatment of childhood cancer in Africa. Action of the Franco-African childhood cancer group]

The childhood cancer survival rate is currently 75% in industrialized countries. Rates in developing countries are much lower. The Franco-African Childhood Cancer Group (French acronym, GFAOP) was founded in 2000 with aim of reducing this unfavorable situation in Africa. The GFAOP has developed two forms of action. The main form consists of organizing two- to twelve-month training sessions for physicians and nurses in France and Morocco. The other form involves assessing the feasibility of modern treatment protocols for various cancers in Africa. The first feasibility trials were carried out on nephroblastoma and Burkitt's lymphoma in 12 pilot units in North Africa, West Africa, and Madagascar. In the first study from 2001 to 2005 we treated 306 cases of Burkitt's lymphoma using French LMB protocols adapted to the African setting and achieved a survival rate of 61%. A second study started in 2005 using Endoxan alone achieved a highly satisfactory survival rate of 73% for neuroblastoma in all stages except bilateral. Altogether from 2001 to 2007 more than 1000 cases of nephroblastoma and Burkitt's lymphoma were treated in African hospitals by African doctors and nurses. No patients were transferred to Europe. The GFAOP supplied drugs when necessary and took care of most travel expenses. African and French doctors worked together on protocol design, trial management, and data analysis. These promising results show that the latest therapeutic techniques can be used to treat childhood cancer in Africa by adapting the protocol to conditions in developing countries. Sanofi-Aventis Laboratories in association with the International Union against Cancer has launched a major campaign to improve Pediatric Oncology in developing countries. Projects in four GFAOP units are being financed through this campaign. In 2006 the GFAOP began assessment of two new treatment protocols, i.e., one for acute lymphoblastic leukemia and the other for Hodgkin's disease. Two other projects are being planned, i.e., one for treatment of retinoblastoma and the other for treatment of some types of brain tumors.

Reduction of postoperative chemotherapy in children with stage I intermediate-risk and anaplastic Wilms' tumour (SIOP 93-01 trial): a randomised controlled trial

BACKGROUND

Present treatment for Wilms' tumour is very successful. Now, efforts are aimed at reducing toxicity and burden of treatment by shortening schedules without loss of effectiveness. The objective of this randomised trial was to assess whether postoperative chemotherapy for patients with stage I intermediate-risk and anaplastic Wilms' tumour could be shortened to only 4 weeks from the standard 18 weeks, while maintaining equivalent event-free survival.

METHODS

Between June, 1993, and June, 2000, 410 patients were randomly assigned after four doses of vincristine plus one course of dactinomycin postoperatively either to stop further adjuvant chemotherapy (no further chemotherapy group, n=200), or to receive a further two courses of the same chemotherapy (standard group, n=210). Previous treatment consisted of chemotherapy before nephrectomy of four doses of vincristine and two courses of dactinomycin followed by surgical resection of the tumour. Eligible patients were at least 6 months old and had stage I tumours with either intermediate-risk histology or anaplasia. The primary endpoint of this equivalence trial was 2-year event-free survival. Both per-protocol and intention-to-treat analyses were done.

FINDINGS

By 2 years, 18 recurrences were reported in the standard group, and 22 in the no further chemotherapy group. Event-free survival was 91.4% (95% CI 87.5-95.2) for the no further chemotherapy group and 88.8% (84.3-93.2) for the standard group (difference=2.6%, upper 97.5% confidence limit 8.4%). The null hypothesis, that experimental treatment is less effective than standard treatment, could be rejected (p=0.008).

CONCLUSIONS

Shortening duration of chemotherapy could reduce acute and late side-effects and inconvenience for patient and parents while maintaining effectiveness, and could be beneficial in terms of health costs.

Primary nephrectomy for emergency: a rare event in the International Society of Paediatric Oncology Nephroblastoma Trial and Study no. 9

Experience of the International Society of Paediatric Oncology (SIOP) Trials and Studies indicates that the preoperative chemotherapy in Wilms' tumour improves stage distribution, decreases complication rate and reduces postoperative treatment. However, some situations may lead to prompt primary surgery. The aim of the study is to assess reasons leading to primary emergency nephrectomy. Records of 720 patients with non-metastatic unilateral nephroblastoma who were registered in the SIOP Trial and Study 9 were reviewed. Twenty-four (3%) cases of primary emergency nephrectomy were identified. Reasons leading to emergency nephrectomy were massive bleedings from ruptured tumours in 13 patients, suspicion of an "acute abdomen" in 7, bowel occlusion in 2 and other in 2. Postoperative treatment included radiotherapy in 71% of cases and anthracyclines in 92%. Complications were frequent and happened in 25% of patients, the outcome however, was favourable and 22 of 24 patients are alive (from 9 to 79 months). The 7 patients with a suspicion of an "acute abdomen" probably constitute the group which could have been markedly reduced if adequately diagnosed and observed prior to surgery.

Optimal duration of preoperative therapy in unilateral and nonmetastatic Wilms' tumor in children older than 6 months: results of the Ninth International Society of Pediatric Oncology Wilms' Tumor Trial and Study

PURPOSE

To determine the optimal duration of preoperative chemotherapy to further increase the proportion of stage I tumors by comparison of two regimens in the treatment of patients older than 6 months who have unilateral Wilms' tumor.

PATIENTS AND METHODS

Eligible patients (n = 382) initially received four weekly doses of vincristine (VCR) and two courses of actinomycin D (AMD) and were randomized either to be operated on (4-week group [n = 193]) or to receive 4 more weeks of the same chemotherapy regimen (8-week group [n = 189]). The assessment criterion was the observed percentage of stage I tumors. After surgery, patients were assigned according to tumor stage and histology to four different treatment groups: stage I and favorable histology (n = 5) were to have no further treatment (NFT); stage I and standard histology or anaplasia (n = 244), VCR and AMD for 17 weeks (AV); stages II and III and favorable or standard histology, VCR, AMD, and an anthracycline for 27 weeks (AVE) with no abdominal radiotherapy for stage II N0 disease (n = 75) or with a 15-Gy dose of abdominal irradiation (RTH) in case of stages IIN1 and III (n = 56). Anaplastic tumors staged higher than I or clear-cell sarcoma of the kidney (14), AMD, VCR, an anthracycline, and ifosfamide for 36 weeks (DEVI).

RESULTS

No advantage was found in favor of prolonged preoperative treatment. The percentages obtained for the 4-week and the 8-week groups, respectively, were as follows: stage I, 64% versus 62%; intraoperative tumor rupture rate, 1% versus 3%; 2-year EFS, 84% versus 83%; and 5-year OS, 92% versus 87%. Two-year EFS and 5-year OS rates, respectively, of the different treatment groups were as follows: NFT, 100% for both EFS and OS; AV, 88% and 93%; AVE, 84% and 88%; AVE RTH, 71% and 85%; and DEVI, 71% and 71%. The rate of abdominal recurrences in stage II N0 nonirradiated patients was 6.6%.

CONCLUSION

The 4-week schedule pre-nephrectomy chemotherapy regimen should be considered the standard treatment. Clinical trials should continue to improve the cure rate of high-risk patients and the quality of life of children with a more favorable prognosis.

WT1 splicing alterations in Wilms' tumors

Hereditary and sporadic forms of tumors are generally related to germ-line and somatic mutations of the same tumor suppressor gene. Unexpectedly, in Wilms' tumor, somatic mutations of the WT1 gene were found only occasionally in sporadic cases, although constitutional mutations of this gene are clearly associated with predisposition. It has been suggested that abnormal splicing may be another mode of somatic WT1 alteration. However, this idea was based on the analysis of a small series of tumors, precluding accurate evaluation of the frequency of such changes. To investigate WT1 changes at the somatic level in more detail, we analyzed the levels of the four isoform transcripts produced by alternative splicing events in a large series of 50 tumors, normal mature kidneys, and fetal kidneys. We characterized splicing alterations in 63% of sporadic Wilms' tumors. Moreover, taking into account the decreased and increased overall levels of WT1 mRNA, the percentage of sporadic tumors with changes in WT1 expression reached 90%. Whether and how these alterations of expression play a role in the tumorigenic process remain to be evaluated.

The role of preoperative chemotherapy in the management of Wilms' tumor. The SIOP studies. International Society of Pediatric Oncology

More than 25 years after introducing preoperative chemotherapy for Wilms' tumor, the benefits of this approach are well known. The preoperative protocol results in easier operations with significantly fewer tumor ruptures during surgery and a favorable stage distribution. Acute toxicity and late effects are minimized without jeopardizing disease-free and overall survival. Future clinical trials of Wilms' tumor should seek additional risk factors to stratify and individualize treatment. These prognostic factors will improve the cure rates for high-risk patients by intensifying therapy and the quality of life for children with more favorable prognosis by lowering therapy to a minimum. As is true for radical surgery, partial nephrectomy in unilateral disease must be evaluated in carefully selected patients according to clear and well-defined indications. Molecular genetic studies should increase understanding of Wilms' tumor, influencing treatment and outcome.

Complete necrosis induced by preoperative chemotherapy in Wilms tumor as an indicator of low risk: report of the international society of paediatric oncology (SIOP) nephroblastoma trial and study 9

BACKGROUND

The SIOP Nephroblastoma therapeutic protocols include a period of preoperative chemotherapy followed by nephrectomy and a period of postoperative chemotherapy. From the outset, identification of low-risk groups has been an aim of the SIOP Nephroblastoma Trials and Studies. Now that 90% of children with Wilms tumor can be cured, attention is even more focused on the identification of patients who could benefit from less aggressive postoperative therapy, thus minimizing the morbidity and late effects associated with treatment. The prognostic implications of total necrosis in nephroblastoma after chemotherapy have not been investigated hitherto.

PROCEDURE

Between November 1, 1987 and June 30, 1993, 599 patients referred to the SIOP-9 Nephroblastoma Trial and Study were preoperatively treated and classified as stages I-IV nonanaplastic Wilms tumor.

RESULTS

Of these 599 patients, pathologic examination of the nephrectomy specimen revealed a completely necrotic Wilms tumor (CNWT) with no viable tumor remaining in 59 (10%): these comprised 37 stages I-III and 22 stage IV. Of these patients, 58 (98%) had no evidence of disease at 5 years vs. 90% for the rest of the cohort (P < 0.05). Stages I-III patients represented 63% of CNWT and had a 97% overall survival rate. The only death was related to veno-occlusive disease and occurred in a stage I patient in the month following nephrectomy. Stage IV patients represented 37% of CNWT (vs. only 10% of all other cases of unilateral nonanaplastic Wilms tumor) and had a 100% rate of survival. Children with CNWT were older (mean 59 months vs. 43 months); their tumor at diagnosis was larger and had regressed more significantly at subsequent ultrasound examination. The data also uphold the hypothesis that Wilms tumors of blastemic pattern are most aggressive, but also are extremely responsive to chemotherapy.

CONCLUSIONS

Patients with unilateral nonanaplastic WT that showed total necrosis following preoperative chemotherapy had excellent outcome and should benefit from less aggressive postoperative treatment in further trials. Other very responsive tumors, such as Wilms with <10% viable tumor, should also be assessed.

Hepatotoxicity in patients treated according to the nephroblastoma trial and study SIOP-9/GPOH

BACKGROUND

A major problem for children receiving Wilms tumor (WT) chemotherapy is hepatotoxicity, which may even be life-threatening. Dactinomycin (AMD) has been shown to be an important factor, as has abdominal irradiation.

PROCEDURE

In the nephroblastoma trial and study SIOP-9 (SIOP-9) two different regimens for the application of AMD were used (standard dose over 3-5 days vs. double dose on a single day). In children at increased risk for local relapse, postoperative abdominal irradiation was given. We analyzed the influence of AMD and radiotherapy on the development of hepatotoxicity in 481 children treated in centers of the German Paediatric Oncology and Haematology Society (GPOH). A special questionaire was sent out for all patients with reduced treatment or delay of more than 1 week because of hepatotoxicity. Because SIOP and the National Wilms Tumor Study (NWTS) used different criteria to asses hepatotoxicity,we applied both definitions.

RESULTS

All 72 cases of mild or severe hepatotoxicity occurred during treatment with AMD over 3-5 days with the standard dose (9.4-22.5 microgram/kg/week) compared to none in the group receiving a double dose on 1 day (3.75-8 microgram/kg/week; P < 0.001). Irradiation of the right abdomen, including parts of the liver, enhanced liver toxicity significantly, with a relative risk (RR) of 2.6 (P < 0.003). Preoperative liver toxicity was more frequent in smaller children (P = 0.02) and especially if no dose reduction was done in children with body weight of less than 12 kg (RR 5.3, P = 0.01). If severe liver toxicity was defined according to NWTS criteria, 10% of all treated patients were affected compared to 4.8% if McDonald's criteria for hepatic veno-occlusive disease (VOD) were applied.

CONCLUSIONS

To diminish the hepatotoxicity of WT treatment, AMD dose intensity should be reduced (below 10 microgram/kg per week), especially in smaller children or when the liver is irradiated.

Misstaging in nephroblastoma. Causes and consequences. A report of the Sixth Nephroblastoma Trial and Study of the International Society of Paediatric Oncology

In the Wilms tumour trials and studies of the International Society of Paediatric Oncology (SIOP), the postoperative treatment is based on the extension (stage) and the histological type. Incorrect staging results in under- or overtreatment. The authors studied the causes and consequences of misstaging in SIOP 6. In this study, the final stage was defined by a central panel of pathologists after review of the surgical and histopathological forms and study of representative microscopical sections. In 46 out of 509 trial patients there was a discrepancy between the final stage and the stage determined at the participating centres: 33 patients were understaged of whom 27 survived more than 5 years (18% died) and 13 patients were overstaged of whom 11 survived more than 5 years (15.3% died). All children with tumour extension into the renal pelvis and treated as stage I instead of stage II survived without evidence of disease. Therefore, it was decided to treat these children in the next study as a stage I. In 17 cases the treatment was based on the surgical stage before the pathological stage was known or the treatment was given according to the stage determined by the local pathologist without waiting for the panel review. The numbers are too small to conclude on the consequences of overtreatment on late effects. For all clinicians the main and most important conclusion of this study is: wait for the final pathology report before initiating postoperative therapy.

The role of preoperative chemotherapy in the treatment of nephroblastoma: the SIOP experience. Societe Internationale d'Oncologie Pediatrique

Treatment of Wilms' tumor is an example of success of modern oncology. A combination of surgery, radiotherapy, and chemotherapy is widely accepted as the efficacious treatment of nephroblastoma. However, timing of each part of the treatment differs, in various protocols: the Societe Internationale d'Oncologie Pediatrique (SIOP) recommends the diagnosis based on imaging and metabolic exclusion of neuroblastoma to reduce the biopsy-related risk of spillage. In patients more than 6 months old, the treatment starts with the preoperative chemotherapy to improve the stage distribution at surgery and decrease the complications rate. Patients with advanced nephroblastoma, as those with vena cava thrombus and lung metastases, can benefit the most from the pretreatment. Results from the SIOP studies 6 and 9 confirm these statements: the stage distribution after the pretreatment reveals more than 50% of cases staged I, the 4-year disease-free survival in pulmonary stages IV was 83%, and of 42 patients with vena cava thrombus still present at surgery, 38 are alive from 27 to 109 months.

[Nephroblastoma, model of childhood cancer responding to chemotherapy]

Cancer incidence is low in children. Childhood tumors are different from cancers seen in adults: their growth is rapid, but they respond well to radiotherapy and chemotherapy. In the case of Wilms Tumor, Actinomycin D, Vincristine and Doxorubicin were first used with success. Ifosfamide, Etoposide and Carboplatin are now also used in selected cases. But efficient treatments have important drawbacks: growth defects in the case of radiotherapy, late cardiac toxicity due to Doxorubicin, leukemias as second tumors following Etoposide. Treatment strategy is based on prognostic factors in Wilms' tumor, and the risk/benefit ratio assessment for each group of patients, considering survival probability and the risk of late effects. Large randomised studies in the USA and in Europe resulted in cure rates over 90%, with very few expected sequelae. Preoperative chemotherapy is now successfully applied to other tumors in children.

High-dose melphalan, etoposide, and carboplatin followed by autologous stem-cell rescue in pediatric high-risk recurrent Wilms' tumor: a French Society of Pediatric Oncology study

PURPOSE

The three-drug combination of melphalan (M), etoposide (E), and carboplatin (C) followed by autologous stem-cell (ASC) rescue has been evaluated prospectively by the French Society of Pediatric Oncology (SFOP) in pediatric high-risk recurrent (HRR) Wilms' tumor (WT) patients with chemotherapy-responsive disease.

PATIENTS AND METHODS

From October 1988 to October 1994, 29 patients with HRR WT were treated in nine SFOP centers. Two additional patients with stage IV anaplastic WT were consolidated in first complete response (CR) with the same regimen and have been studied separately. The regimen consisted of M 180 mg/m2 for 1 day, E 200 mg/m2/d for 5 days, and C at a daily targeted area under the concentration-time curve (AUC) of 4 mg x min/mL for 5 days. ASCs were reinfused 48 hours after M.

RESULTS

Twelve of 28 assessable patients with HRR WT are still in continuous CR at a median of 48.5 months (range, 36 to 96) after consolidation. Disease-free survival (DFS) and overall survival (OS) estimated by the Kaplan-Meier method at 3 years were 50%+/-17% and 60%+/-18%, respectively. Sixteen patients relapsed at a median of 8.5 months (range, 3 to 53) after consolidation. Toxicity data are available in 31 grafted patients. Grade III and IV toxicities included hematologic side effects (n=31), hemorrhage (n=8), mucositis (n=24), diarrhea (n=12), renal disorders (n=8), and pneumonitis (n=3).

CONCLUSION

The adverse prognostic factors (APF) used to select patients for this dose-intensive chemotherapy define children with very-poor-risk recurrent WT. Despite high treatment-related toxicity, about half of these patients remain disease-free at 3 years. Patient outcome is statistically better when high-dose chemotherapy (HDCT) is performed as early as the second CR or partial response (PR). Novel therapeutic approaches with innovative preparative regimens are warranted for the remaining high-risk patients.

Rarity of surgical complications after postchemotherapy nephrectomy for nephroblastoma. Experience of the International Society of Paediatric Oncology-Trial and Study "SIOP-9". International Society of Paediatric Oncology Nephroblastoma Trial and Study Committee

The aim of the study was to assess rates and types of nephrectomy-related complications in children nephrectomized for nephroblastoma after preoperative chemotherapy. Records of 598 Wilms' tumour patients registered in the International Society of Paediatric Oncology Trial & Study No. 9 (SIOP-9), and pretreated correctly according to the protocol with vincristine + actinomycin D +/- epirubicine or adriamycin prior to nephrectomy, were retrospectively reviewed. Forty-nine patients (8%), who suffered from 54 complications, were identified. Most frequent events were small-bowel occlusions (3.7%) and tumour ruptures (2.8%). Other complications were registered in 2.0% of cases. The low rate of nephrectomy complications and no deaths related to registered ones, are another argument for preoperative chemotherapy in Wilms' tumour patients.

Veno-occlusive disease of the liver in children treated for Wilms tumor

INTRODUCTION

Hepatotoxicity consistent with the clinical diagnosis of veno-occlusive disease (VOD) of the liver has been suspected after conventional anti-cancer chemotherapy in children.

METHODS

To establish the incidence of hepatotoxicity and its relationship with VOD, we analyzed toxicity data obtained on 511 children affected by Wilms tumor and treated according to the SIOP-9 protocol. They all received pre- and postnephrectomy chemotherapy using dactinomycin (AD) and vincristine (VCR) +/- other drugs +/- radiotherapy according to surgical stage and histology.

RESULTS

Sixty-four patients suffered at least one episode of hepatotoxicity and 41 satisfied the criteria for a clinical diagnosis of VOD. In this latter group, toxicity occurred during preoperative treatment in 15 patients and was confirmed histopathologically in 9 of the 16 liver biopsies obtained. There was a higher percentage of children aged less than 1 year at diagnosis in the VOD group than in the other patients (24% vs. 11.4%). The degree of liver damage in the younger patients seems important, as suggested by a higher increase in transaminases. VOD developed in 12% of the 68 irradiated children vs. 7% in the non-irradiated group. Statistical analysis showed an increased risk of VOD in younger patients (p < 0.001) and in those receiving radiotherapy (p < 0.001). All patients recovered after 6-180 days using supportive therapy only.

CONCLUSIONS

(1) 8% of children treated according to the SIOP-9 protocol, developed hepatotoxicity consistent with VOD. Excluding patients who received radiotherapy, the incidence was 6%. These figures are much higher than in earlier reports, though different diagnostic criteria were used. (2) Chemotherapy with AD and VCR seems to be a major cause of VOD. (3) Risk factors are young age and concomitant radiotherapy. (4) VOD does not prejudice positive outcome for these patients.

Second malignant neoplasms in patients treated on SIOP Wilms tumour studies and trials 1, 2, 5, and 6

The incidence of second malignant neoplasms (SMNs) was investigated among 1,988 patients with complete data, enrolled in the SIOP Wilms tumor trials and studies 1, 2, 5, and 6, treated between September 1971 and October 1987. By the end of 1992, eight SMNs were documented, whereas only 1.3 were expected (standardized incidence ratio [SIR] = 4.15; 95% CI = 1.79, 8.17). The risk increases in the first 10 years from diagnosis, while no apparent excess of risk is observed in the subsequent periods. This finding however is difficult to interpretdue to the low statistical power. The cumulative incidence of a second cancer observed at 15 years after Wilms tumor diagnosis was 0.65%. Six SMNs were registered in the cohort of patients treated in the SIOP studies 1, 2 and 5 (999 cases) compared to the two cases observed in the SIOP6 cohort (989 cases). If the suggested reduced incidence of second cancers between SIOP1-5 and SIOP6 patient cohorts is confirmed by longer follow-up, it might reflect changes in the treatment protocols.

Characterization of regions of chromosomes 12 and 16 involved in nephroblastoma tumorigenesis

There are at least three loci involved in Wilms' tumor (WT) tumorigenesis: WT1 in 11p13, WT2 in 11p15.5, and WT3, as yet unmapped. A compilation of cytogenetic data published for 107 WT revealed that deletion of chromosome 16 and duplication of chromosome 12 occur as frequently as the well-documented 11p deletions. Allelic imbalance for chromosomes 16 and 12 was investigated in a series of 28 WT. By use of a large panel of restriction fragment length polymorphisms and (CA)n probes, we demonstrated loss of heterozygosity (LOH) for 16q in seven (25%) of the tumors. The whole length of 16q was involved in six of the tumors. Moreover, consistent with a previous report of 16q13 LOH in a sporadic WT and a constitutional breakpoint with a Beckwith-Wiedemann patient, we map a region of particular interest to between D16S308 and D16S320. The assumption that 16q LOH may be an early event was based on: 1) the detection of 16q LOH in one case of nephroblastomatosis; 2) the presence of a complete (clonal) 16q LOH in a tumor with partial (mosaic) 11p LOH; and 3) 16q LOH as the sole abnormality in one WT. By quantification of chromosome 12 allelic imbalance, we detected duplication in 18% of the total series and in 25% of the sporadic unilateral cases. The common region extended from the centromere to D12S7 in 12q21.1-q23. We also suggest that the various pathogenetically important loci are not equally involved in the different forms of WT and that their sequential involvement may differ.

The management of relapsed Wilms tumor

Relapsed Wilms tumor is often very responsive to re-treatment, and cures are possible in many cases. Recurrent Wilms tumor forms a heterogeneous group because initial therapies vary widely. Given the complexity of the problem, there is a great need for an organized clinical investigative approach. Ideally, the treatment of initial relapse should be specified by the primary treatment protocol in order to better evaluate overall survival as an end-point for new primary therapy strategies. This is especially appropriate for Wilms tumor, because the investigations of this tumor over the last 20 years have attempted to determine the minimal therapy necessary for cure. Thus, survival rather than relapse-free survival is the most appropriate criterion for the success of a primary retreatment regimen. This investigative approach would also allow evaluation of treatment strategies tailored to a specific patient population. Important questions remain for those who treat recurrent Wilms tumor. Defining the role of high-dose therapy, defining the role of total body irradiation in high-dose therapy regimens, and defining the benefit and toxicity of cyclophosphamide compared with ifosfamide are three current questions under investigation. Developing new agents and regimens effective against Wilms tumor, especially against anaplastic tumors, RTK, and CCSK, is extremely important if progress is to be made in treating these tumors after relapse. Finally, there is a strong need to develop biologic information about tumors that recur, so not only will we better understand why patients relapse but also we can develop therapy tailored specifically to the biology of the recurrent tumor.

[Pediatric aspects of anthracycline cardiotoxicity and practical implications for prevention]

Discovered during the sixties, anthracycline antibiotics are today widely used anti-cancer drugs. Their potentially fatal cardiac toxicity, which is related in part to the total cumulative dose, has been described since 1967. The aim of this paper is to describe their biological and clinical toxic effects on the heart, especially of children, and to propose prevention guidelines. The mechanisms of cardiac toxicity, with their destructive consequences on functional myocytes reserve, are shortly recalled. Acute, sub-acute and chronic clinical aspects of anthracycline's cardiomyopathy are the subject of a literature review. In Pediatric Oncology, the prolonged survival usually observed allows delayed congestive heart failure to occur by myocardial reserve insufficiency, as hemodynamic needs are quickly increasing, especially at the end of the somatic growth. Furthermore, the frequency of cardiac abnormalities is increasing with time after therapy, reaching about half of the explored patients after 15 years. The main known methods to prevent such a toxicity are reviewed. The parcimonious use of anthracyclines is already seen in children. Every method to decrease the maximal plasma concentration of the drug (weekly schedule or prolonged infusion) has to be considered. The active cardioprotectant agent such as ICRF-187, is in clinical development. Detection, prevention, and therapy of cardiac abnormalities, which are likely to precede delayed heart failure, still remains a difficult problem in these more and more numerous children to be cured of cancer.

Paediatric surgical oncology. 5--Nephroblastoma. International Society of Paediatric Oncology (SIOP) Nephroblastoma Trial & Study Committee

The favourable results from the treatment of Wilms' tumour are an example of the success of multimodal therapy in paediatric oncology. The epidemiology, methods of diagnosis, benefits of pre-operative chemotherapy, basic principles of surgery and post-operative treatment modalities are presented. The approach to the management of Wilms' tumour considered in this paper is mainly that of the International Society of Paediatric Oncology.

[Multilocular cyst of the kidney in a child. Value of MRI?]

We report one case of multilocular cyst of the kidney in one year and three months female infant who underwent echography, computed tomography and MRI before surgery. MR image accurately reflect the morphology of the tumor: the capsule is hypointense on T1-weighted images, the septa show moderate enhancement with intravenous contrast. Varied intensities from fluid in the visualised locules presumably represent different concentration of proteins. MR imaging features are highly suggestive but non pathognomonic of the disease. Positive diagnosis always require histology.

[The immigration of Italian patients to foreign countries. Analysis of the Gustave Roussy Institute series]

Most Italian patients who migrate to foreign countries to receive health care, choose France. The Gustave Roussy Institute (IGR) located in Villejuif, a town in the suburbs of Paris, is one of the most important center for cancer diagnosis and treatment in France. The aim of this issue has been to evaluate the admissions of Italian patients in terms of cause of admission, treatment and area of residence of the patients. We analysed the series of Italian patients admitted to IGR from 1988 to 1991; during that period 8159 Italian patients were hospitalized (2.8% younger than 15 years, 84.3% between 15 and 64 years and 12.9% older than 64 years). Most of those patients were resident in the South of Italy (more than 63%) and in particular they came from the region Sicily (27.4%) and Campania (18.8%). A different pattern seems to distinguish patients coming from the Center and the North of Italy from those from the South. In fact the aim of this migration was, for the former, a consultation on the therapy that they had, in large part, already undergone in Italy while the latter wanted to start their treatment there. The admissions related to the three most frequent cancers (breast, lung, lympho-hemopoietic system) have been analysed. The majority of patients were from the South of Italy. Breast cancer patients have migrated to the IGR looking for a post-surgical treatment while lung patients have been in large part treated for the first time at the IGR.

The French Wilms' tumour study: no clear evidence for cancer prone families

Wilms' tumour of the kidney is known to occur in Beckwith-Wiedemann syndrome. It has also been described in four cancer prone families displaying Li-Fraumeni syndrome but it is not usually considered to be part of this syndrome. In order to detect particular familial cancer aggregations associated with this tumour, we studied the cancer incidence and mortality among relatives of the 501 Wilms' tumour patients in the French Wilms' Tumour Study. We found no familial association with breast cancer or soft tissue sarcomas which are the most common cancers in the Li-Fraumeni syndrome. However, we found two significant familial associations of Wilms' tumour with bone cancers on the one hand and with brain tumours on the other hand. These associations could reflect a small proportion of families segregating for some susceptibility gene. This should then be confirmed at the molecular level.

Etoposide and carboplatin: a highly effective combination in relapsed or refractory Wilms' tumor--a phase II study by the French Society of Pediatric Oncology

PURPOSE

Since we had previously demonstrated encouraging efficacy of etoposide in patients with relapsed or refractory Wilms' tumor (WT), the likely synergism between etoposide and platinum compounds prompted us to conduct a phase II study of a combination with carboplatin.

PATIENTS AND METHODS

Twenty-six relapsed or refractory WT patients were included in a phase II study of two courses of combination etoposide 100 mg/m2/d for 5 days and carboplatin 160 mg/m2/d for 5 days, with a 21-day interval between the two courses. Initial stages were I (n = 2), II (n = 8), III (n = 6), IV (n = 6), V (n = 3), and unknown (n = 1). Sites of diseases were lung(s) (11 patients), abdomen-pelvis or liver or primary tumor (six patients), and multiple (eight patients). Histology was unfavorable in three of 26 patients.

RESULTS

Complete response (CR) was documented in eight patients and partial remission (PR) in 11 (overall response rate, 73%). Stable disease (SD) was observed in five patients and progressive disease (PD) in two. Thrombocytopenia (grade IV) was the major toxicity, and platelet transfusions were required in all but two patients. Grade III anemia and grade III to IV neutropenia were seen in 19 and 23, respectively, of 25 assessable first courses. Venoocclusive disease of the liver was fatal in one child who had undergone irradiation to the whole abdomen, 8 weeks before study.

CONCLUSION

Combination etoposide and carboplatin has impressive activity in refractory or relapsed WT at the cost of high-grade hematologic toxicity, especially thrombocytopenia. It is of great interest in second-line therapy, since eight of 26 patients are still alive in continuous CR (median follow-up duration, 40 months; range, 24 to 56). This combination deserves further investigation as first-line or consolidation treatment.

Adult Wilms' tumour: review of 22 cases

The Institut Gustave Roussy experience with nephroblastoma in 22 patients older than 16 years during a 19-year period (1973-1992) was retrospectively reviewed. All patients underwent a nephrectomy. There were 4 stage I, 8 stage II, 3 stage III and 7 stage IV patients. Initial postnephrectomy therapy included single modality approach in 7 patients (radiotherapy in 1 and chemotherapy in 6) and combined modality approach (radiotherapy and chemotherapy) in 15 patients. The agents used most often were actinomycin, vincristine and doxorubicin. 2 of 7 (29%) and 7/15 (47%) patients are disease-free survivors after first-line treatment. Salvage chemotherapy was given in 13 patients. Only 1 patient experienced a subsequent sustained complete remission. After a mean follow-up of 100 months (range 10-240), 12/22 patients (55%) are alive, including 10 who are disease-free (45%). We confirm that adult patients are likely to have more advanced disease and poorer prognosis than children. The combined modality approach is more active than one-modality therapy. Aggressive treatment, including the three-drug regimen actinomycin+vincristine+doxorubicin, regardless of stage, associated to irradiation starting from stage II, is recommended.

Radiotherapy in the SIOP (International Society of Pediatric Oncology) nephroblastoma studies: a review

For decades radiation has generally been accepted as a valuable supplement to surgery in the treatment of Wilms' tumor; unfortunately, it may produce undesirable late effects. It turned out, however, that when treatment is adjusted to known variables, the risk for late sequelae can be diminished in some groups of children. SIOP clinical trials have been based on children with unilateral tumors of standard histology and free of metastasis at diagnosis. The first two clinical trials, SIOP-1 (started in 1971) and SIOP-2 (started in 1974), established the beneficial effect (such as less ruptures, lower stage) of preoperative radiation and actinomycin D (AMD) in SIOP-2, with all children having radiation therapy either preoperatively, postoperatively, or both. In the SIOP-5 trial (started in 1977), preoperative radiation therapy and AMD were compared with preoperative chemotherapy resulting in only 50% of children having radiation. The result permitted disuse of preoperative radiation in the SIOP-6 trial (started in 1980), where only one-third of the patients received postoperative radiation therapy. At present, in the SIOP-9 trial (started in 1987), fewer than 20% of children are having radiotherapy. The survival rates meanwhile have been increasing steadily from 64% in SIOP-1 to 84% in SIOP-6 for stages I, II, and III combined.

[Nephroblastoma (Wilms' tumor)]

Nephroblastoma is one of the frequent tumours in children. It is the tumour that has most benefited from advances in chemotherapy made during the last twenty years, a period in which its cure rate has increased from 50 to 90%. This tumour is easy to diagnose by radiology and ultrasonography. Its histological features are now well known, and diagnostic problems have become rare. What predominates at present is research on the link which exists between the development of these tumours and certain congenital malformations on the one hand, and certain chromosomal anomalies on the other hand. Deletion of chromosome 11 short-arm is the most common of these anomalies. Nephroblastoma might be one of those tumours which develop due to derepression of cell proliferation. Treatment rests on nephrectomy and chemotherapy which nowadays consists of numerous and effective drugs. Radiotherapy is still used but as little as possible because of the sequelae it creates. Treatment has much benefited from preoperative chemotherapy which improves the results of the latter.

Etoposide in relapsed or refractory Wilms' tumor: a phase II study by the French Society of Pediatric Oncology and the United Kingdom Children's Cancer Study Group

PURPOSE

Despite a high cure rate of approximately 85% in Wilms' tumor by multimodality therapy, to date only four drugs are known to be active against such tumors. There is a clear need for new active drugs.

PATIENTS AND METHODS

Thirty-one patients with relapsed or refractory Wilms' tumor from three British and 14 French centers were treated with intravenous (IV) etoposide 200 mg/m2 daily for 5 days. Original stage was I (n = 3), II (n = 7), III (n = 9), IV (n = 10), and V (n = 2). Prior chemotherapy, administered initially or at relapse, included vincristine and dactinomycin in all cases, doxorubicin or epirubicin in 30, and ifosfamide in 20. Sites of relapse or resistant disease were lung in 13, abdomen or pelvis in six, liver in one, and multiple in 11. When entered onto the study, 12 patients were in first relapse, 10 in second relapse, and four in third or more relapse. Five had never obtained a complete remission. All but two (progressing) patients received two courses of etoposide, the second course being administered at day 21.

RESULTS

A complete response (CR) was documented in two patients, partial response (PR) in 11, stable disease in 10, and progressive disease (PD) in eight. The duration of response could not be evaluated, because all responding patients were subsequently treated with multimodality therapy. The major toxicities observed were neutropenia and thrombocytopenia, but most patients had been heavily pretreated. No toxic death clearly associated with etoposide was noted.

CONCLUSION

It is concluded that etoposide in this schedule is an active agent in Wilms' tumor and should be considered for inclusion in regimens for high-risk patients, such as those with metastatic disease at diagnosis and those who relapse after multiagent chemotherapy.

Results of the Sixth International Society of Pediatric Oncology Wilms' Tumor Trial and Study: a risk-adapted therapeutic approach in Wilms' tumor

PURPOSE

The Sixth International Society of Pediatric Oncology study (SIOP6) concerned Wilms' tumor with favorable histology, preoperatively treated to obtain a high rate of stage I patients, and sought to reduce treatment for patients with stage I and stage II negative nodes (IIN0) tumors and to find better therapy to prevent relapses in stage II positive nodes (IIN1) and stage III patients.

PATIENTS AND METHODS

Eligible patients (N = 509) had received four weekly doses of vincristine (VCR) and two courses of dactinomycin (AMD) preoperatively and were assigned after surgery, according to stage and lymph node involvement, to three different prognostic groups, which were to be randomized. Stage I patients (n = 303) received VCR and AMD either for 17 weeks (S) or 38 weeks (L). Stage IIN0 patients (n = 123) received either 20 Gy irradiation (R+) or no irradiation (R-) and received VCR and AMD for 38 weeks. Stage IIN1 and III patients (n = 83) received intensified VCR and AMD (INTVCR) versus VCR, AMD, and Adriamycin (ADRIA; Doxorubicin Farmitalia Carbo Erba, Rueil, Malmaison, France; doxorubicin). Assessment criteria were 2-year disease-free survival (DFS) and 5-year survival (SURV) percentages. A stopping rule was added that took into account abdominal recurrences for the stage IIN0 trial.

RESULT

A 52% rate of stage I tumors was obtained, with a low rate of ruptures (7%). The 2-year DFS and 5-year SURV rates according to the different therapeutic groups were stage I, 92% versus 88% (equivalent) and 95% versus 92% for S and L, respectively; stage IIN0, 72% versus 78% (stage equivalent) and 88% versus 85% for R+ and R-, respectively; and stage IIN1 and stage III, 49% versus 74% (P < .029) and 77% versus 80% for INTVCR and ADRIA, respectively, which results in an 82% DFS and 89% SURV rate for the entire trial population. However, six abdominal metastases observed during the first year of follow-up (FU) in the R- group versus none in the R+ group resulted in discontinuation of the stage IIN0 trial.

CONCLUSION

Risk-adapted therapy to limit risk of sequelae is possible. More intensive chemotherapy is necessary to prevent abdominal recurrences in nonirradiated stage IIN0 patients treated preoperatively. A three-drug protocol is necessary in stage IIN1 and stage III patients.

Excess of multifocal tumors in nephroblastoma: implications for mechanisms of tumor development and genetic counseling

Referring to the mutational theory of carcinogenesis in embryonal tumors, it is commonly accepted that patients with multifocal tumors are hereditary cases. This is based on the implicit assumption that each tumor results from a single mutational event occurring in a cell that has already inherited a mutation, and that these tumors are independent. We studied the distribution of tumors in 1,868 cases where the focality was known (SIOP 1, 2, 5 and 6). Using all the supposed gene carriers (bilateral and unilateral multifocal cases), and assuming a Poisson distribution of tumors, we estimated the mean number m of tumors in each kidney to be 0.37. Comparing the observed distribution of cases to the expected one, we found a very bad fit to this hypothesis (P < 10(-9)). This is due to an excess of multifocal tumors, particularly in unilateral cases. These findings have important implications in genetic counseling, since the usual practice of considering multifocal tumor patients as hereditary cases may result in a large overestimate of the recurrence risk in such cases. The implications for the mechanisms of tumor development are also discussed.

Somatic mosaicism for partial paternal isodisomy in Wiedemann-Beckwith syndrome: a post-fertilization event

Genomic imprinting has been implicated in the aetiology of an overgrowth cancer-prone syndrome, the Wiedemann-Beck-with syndrome (WBS). We have demonstrated uniparental disomy (UPD) for paternal chromosome 11p markers in 5 out of 25 sporadic cases (20%). Delineation of the extent of the disomy region may help in understanding the mechanism and the stage, meiotic or mitotic, of disomy formation in this disease and in associated tumours. Our current studies in WBS patients with seventeen 11p and one 11q markers reveal paternal isodisomy, not heterodisomy, in the five cases. For one case we demonstrate unambiguously that partial isodisomy for 11p and somatic mosaicism for UPD resulted from a post-fertilization event. The restriction of isodisomy to part of 11p in another case, and somatic mosaicism for UPD in three other cases, suggest a mitotic recombinational event that must have occurred after fertilization. Mosaic phenotypes reflect the timing of their origin and the fate of the cells involved, as well as the cell-specific pattern of imprinting. Somatic mosaicism for UPD in four cases may thus explain the incomplete forms of WBS. The association of hemihypertrophy in sporadic WBS and even some cases of isolated hemihypertrophy. This is in agreement with a recent report of paternal isodisomy for 11p markers in a patient with hemihypertrophy, Wilms' tumour and adrenocortical carcinoma. Moreover, the risk of developing a tumour seems higher (50%) for patients with paternal 11p UPD than for WBS patients in general (7.5%).

Testing genomic imprinting in Wilm's tumor

Data from 511 cases of Wilms' tumor in France (including 12 familial cases) and 8 pedigrees from the literature were analyzed to test three modifications of Knudson's classical bimutational theory, based on genomic imprinting in Wilms' tumor carcinogenesis. Analysis of data of age at diagnosis and segregation analysis were performed to determine the number of independent events for Wilms' tumor development and to search for a differential role of paternal and maternal alleles. Unexpectedly, we show that only one rare event is required for tumor development in isolated unilateral cases which are considered to be mainly nonhereditary. In familial cases, we observe no effect of the sex of the transmitting parent on either hge at diagnosis or segregation ratio. We show that this could be explained by models of genomic imprinting which assume two nonindependent events, or only one rare genetic event. In bilateral cases we show a bimodality for age at diagnosis which could be due to a mixture of hereditary and nonhereditary cases. This result completely questions the classical assumption according to which all bilateral cases would be hereditary. These findings support the hypothesis that this childhood cancer arises from a variety of etiological pathways and might be useful to find strategies for further molecular investigations.

Preoperative care of infants with nephroblastoma. The International Society of Pediatric Oncology 6 experience

The International Society of Pediatric Oncology (SIOP) recommends preoperative treatment in the management of eligible patients with Wilms' tumor. Until 1980, children younger than 12 months of age (infants) at diagnosis had been excluded from the SIOP trials. SIOP 6, conducted from 1980 to 1987, was the first SIOP study to include infants older than 6 months of age. This retrospective analysis of 145 infants registered to SIOP 6 demonstrates that in infants older than 6 months and having favorable histology (FH), a two-drug preoperative chemotherapy (CT) regimen of 4 weeks significantly ameliorated stage distribution as determined at delayed surgery but did not affect a good outcome. However, the CT dose utilized in SIOP 6 resulted in an unacceptable toxicity in this age group, and SIOP 9, the new SIOP study of Wilms' tumor, recommends a reduced dose of CT in infants. Preoperative CT is not recommended in infants younger than 6 months of age. Specifically, the high incidence (29%) of mesoblastic nephroma in this age group does not justify such an approach. Histopathologic diagnosis should be obtained in these patients before any treatment.

Genetics and epidemiology of Wilms' tumor: the French Wilms' tumor study

A complete family history was obtained for 501 patients with Wilms' tumor, treated in departments of pediatric oncology in whole France. The information was collected by self-questionnaire and/or by interview of parents. The proportion of bilateral cases is 4.6% and there are 12 patients (2.4%) with a positive family history of Wilms' tumor. The affected relatives are most often distant and no first degree relative was affected. Apart from the well-known associations with aniridia, hemihypertrophy, genitourinary anomalies, Beckwith-Wiedeemann, and Drash syndromes, there is also a significant excess of congenital heart defects (P = .008) which remains to be explained. Several findings support the bimutational hypothesis such as earlier diagnosis and increased parental age in bilateral cases. No particular anomalies and no increased frequency of childhood cancer were found in patients' relatives. The frequency of Wilms' tumor in relatives was estimated to be less than 0.4% in sibs, 0.06% in uncles and aunts, and 0.04% in first cousins. These figures are very different from those found in retinoblastoma and suggest that the mechanism may be more complex in Wilms' tumor. This conclusion is in agreement with molecular biology studies in tumors and linkage analysis in multiple case families which suggest that more than one locus is involved.

Wilm's tumor with pulmonary metastases at diagnosis: the significance of primary chemotherapy. International Society of Pediatric Oncology Nephroblastoma Trial and Study Committee

Data from patients with pulmonary metastases (PM) from Wilms' tumor at diagnosis (stage IV) were collected from six European centers. All patients were pretreated with a chemotherapy (CT) regimen consisting of vincristine (VCR), dactinomycin (AD), and Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH). After nephrectomy, local therapy for residual pulmonary disease was considered to avoid whole-lung irradiation. Only four of 36 patients still had multiple inoperable metastases after preoperative CT. Thirty patients survived. Four of them were irradiated. Of the six patients who died, four died of PM, one died of abdominal recurrence, and one of therapy-related disease. Disease-free survival and actuarial survival rates are 83% with a mean follow-up of 4 years postnephrectomy.

A phase II study of ifosfamide in the treatment of relapses in Wilms' tumor

The purpose of this study was to evaluate the antitumor activity and tolerability of ifosfamide (IFO) at a dose of 3 g/m2, given on 2 consecutive days every 2 weeks, in advanced Wilms' tumor patients in whom conventional therapy had failed. Mesna and hyperhydration were concomitantly given to minimize bladder toxicity. A total of 21 patients with advanced Wilms' tumor were entered in the study. The response observed after two courses was complete in 6 patients and partial in 5; 10 did not respond; the median duration of response was 2 months (range, 1-7 months). Leucopenia caused a delay in therapy for 1 or 2 weeks in only three cases. Neither fever nor infection were observed. Of 7 patients who developed hematuria, 3 were among the 17 who concurrently received mesna. The urotoxicity did not interfere with subsequent therapy in these three cases.

How to establish equivalence between treatments: a one-sided clinical trial in paediatric oncology

The design of clinical trial to establish the equivalence of two treatments differs from that of an efficacy trial. The conventional null hypothesis of equivalent treatment efficacy is replaced by a null hypothesis of inequivalence which must be tested by appropriate statistics. In addition, the maximum allowable value of the true difference between the efficacy of two equivalent treatments must be specified. In oncology, such a trial is necessary when a standard treatment is replaced by a new less toxic one of equivalent efficacy. The statistical formulation is one-sided. A trial comparing two pre-operative treatments in childhood nephroblastoma is presented here and analysed according to this methodology.

Bilateral Wilms' tumor: long-term survival and some epidemiological features

Sixty-seven children with a bilateral Wilms' tumor (BWT) who were registered to the International Society of Pediatric Oncology (SIOP) nephroblastoma trial and studies 1, 2, and 5, conducted between 1971 and 1980, were analyzed. The overall 10-year survival was 64%. While most deaths due to tumor occurred within 3 years after diagnosis of bilateral disease, five patients died after 3 years (20%), three with synchronous and two with metachronous BWT. The survival rates for the 42 children with synchronous BWT (follow-up time, 6 1/2 to 14 years) and the 25 children with metachronous BWT (follow-up time, 5 to 13 years) were 69% and 56%, respectively. Due to an improvement in the synchronous group, overall survival improved over the years: 47%, 72%, and 70%, in SIOP 1, 2, and 5, respectively. Age at diagnosis and most advanced tumor stage affected prognosis. Children presenting a tumor manifestation before the age of 2 years had better prognosis than older children. This difference is significant in synchronous BWT. Prognosis for children with local stage 1 or 2 was better than for those with local stage 3. Median age at initial presentation in BWT was lower than in unilateral nephroblastoma and lower in metachronous BWT than in synchronous BWT. Young children presenting with unilateral nephroblastoma should have a careful follow-up of the contralateral kidney for at least the next 3 1/2 years, as most contralateral tumors will develop during this period.

Ifosfamide is an active drug in Wilms' tumor: a phase II study conducted by the French Society of Pediatric Oncology

Twenty-one patients with advanced Wilms' tumor entered a phase II study with high-dose ifosfamide (3 g/m2 over two days every 15 days). Mesna and hyperhydration were associated with minimal bladder toxicity. After two courses, five partial responses and six complete responses were observed. Ten patients did not respond. The median duration of response was 2 months (range, 1 to 7). Therapy was delayed because of leukopenia for 1 or 2 weeks in only three cases. Fever and infection were not observed. Seven patients presented with hematuria, three of whom were among the 17 patients coadministered mesna, which did not interfere with subsequent therapy.

Epidemiological features of Wilms' tumor: results of studies by the International Society of Paediatric Oncology (SIOP)

This descriptive epidemiology study of 1,040 children with Wilms' tumor (WT) registered in the International Society of Paediatric Oncology (SIOP) clinical trials confirms the findings reported by the National Wilms' Tumor Study. The male:female rate was 0.89:1. The mean age at diagnosis of the 43 bilateral cases was significantly younger than children with unilateral renal involvement (32.4 vs 45 months). However, the mean ages of diagnosis for unilateral multicentric and for unicentric WT were very similar. On the other hand, the mean age at diagnosis of children with sporadic aniridia and hypospadias was younger than the mean age of patients with or without other congenital malformations. Thus aniridia as well as hypospadias could be indices of the first mutation, according to the Knudson and Stron hypothesis. WT was reported in two members of each of five families. However, these familial cases were comparable in terms of demographic and clinical features to the nonfamilial ones. These data suggest that the heritable fraction of WT is relatively small and that genetic and environmental factors interact in the development of WT.

Sarcomatous Wilms' tumour with clear cells and hyalinization. A study of 38 tumours in children from the SIOP nephroblastoma file

The International Society of Paediatric Oncology (SIOP) nephroblastoma trial and studies 1, 2 and 5 include 33 sarcomatous Wilms' tumours with a clear cell pattern and five with a hyalinizing pattern among 909 renal tumours. Bone metastases developed in 22 (67%) and one patient (20%) respectively compared with 14 patients (1.6%) in the rest of the series. Both subgroups had clear cells and hyalinization. A constant and characteristic feature of the clear cell tumours was an alveolar vascular pattern which aids in the recognition of this tumour even in fibrous and sclerotic forms. Sarcomatous Wilms' tumour with a hyalinizing pattern had homogeneous areas of sclerosis with clustering of tumour cells but lacked the vascular pattern. Two tumours showed atypia similar to that in malignant rhabdoid tumour of the kidney but had no cytoplasmic inclusions. Five year recurrence-free survival for the entire series was 68%, for sarcomatous clear cell tumours, 42% and for sarcomatous tumours with hyalinizing pattern, 20%.

Abdominal recurrences in Wilms' tumours: a report from the SIOP Wilms' tumour trials and studies

The Wilms' tumour trials and studies conducted from 1971 to 1980 registered 1042 patients. Of these, 82 patients developed an abdominal recurrence. Particulars of these were studied. Half of the recurrences occurred in stage III patients. Often several untoward prognostic factors could be identified, such as large tumour size, difficult operation, incomplete excision, peritoneal adhesions or metastases, tumour extending to renal vein or vena cava. A tumour rupture increases the chance for an abdominal recurrence, especially if appropriate radiotherapy is not given. In many of these cases, postoperative radiotherapy seems to have been insufficiently tailored to the operative findings. For stage III cases, a careful discussion between surgeon, radiotherapist, and pathologist should lead to the optimal radiotherapy field size and dose for each individual patient, so that the risk of abdominal recurrence can be reduced.

Mesoblastic nephromas: a study of 29 tumours from the SIOP nephroblastoma file

In a series of 889 Wilms' tumours we found 29 pure mesoblastic nephromas. The age of the patients varied from newborn to 22 months, but only five were older than four months. Two histologic types were recognized--leiomyomatous (9) and cellular (20) with a fibrohistiocytic appearance. The leiomyomatous type was almost invariably in stage I, smaller and present in younger infants. At operation half of the cellular type has ruptured or infiltrated the renal pelvis or perirenal tissue. Two patients died of postoperative complications. All others are alive after four years and free from disease.