Marie-France Tournade

Preoperative versus postoperative radiotherapy, single versus multiple courses of actinomycin d, in the treatment of Wilms' tumor. Preliminary results of a controlled clinical trial conducted by the international society of paediatric oncology (S.I.O.P.)

The preliminary results of a controlled clinical trial organized by the S.I.O.P. of radiotherapy and chemotherapy in patients with nephroblastoma are presented. Forty‐two centers have participated. Between September 1971 and October 1974, 398 patients were registered; 195 were eligible for the trial and were randomized. The remaining 203 patients were excluded from the trial, but were followed in the same way as the patients in the trial. The results were evaluated in terms of recurrence‐free survival rate and survival rate. Results in patients who received preoperative and postoperative radiotherapy (group A, 73 patients) were compared with the results in patients who recieved only postoperative radiotherapy (group B, 64 patients). The tumor ruptured at surgery in three patients of group A, and in 20 patients of group B, a difference that is statistically significant. No significant difference in survival and recurrence‐free survival between groups A and B is observed at present. Results in patients treated with a single course of actinomycin D (group I, 80 patients) were compared with the results in patients treated with multiple courses (group II, 80 patients). At present, no significant difference is found between the two groups.

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.

Hypercalcemia preferentially occurs in unusual forms of childhood non-hodgkin's lymphoma, rhabdomyosarcoma, and Wilms' tumor. A study of 11 cases

Unusual clinical, radiologic, or histologic findings were found in 11 of 17 cases of hypercalcemia associated with childhood tumors. Four children had undifferentiated lymphoblastic lymphoma with extensive bone involvement, but no visceral or neurologic involvement. At diagnosis, four adolescents with rhabdomyosarcoma had numerous metastases, particularly in the breasts and bone marrow. Three infants had renal tumor without bone metastases. Histologically, their tumors differed from classical nephroblastoma and resembled the malignant rhabdoid tumors of the kidney. These findings allow individualization of three distinct groups of tumors with unusual features which may suggest the presence of hypercalcemia. These tumors appear to have a poor prognosis since all patients but one died of their malignancy.

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.

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 McDonalds 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.

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.