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

A spectrum of findings on computed tomography in paediatric abdominal and pelvic tumours in a Ghanaian teaching hospital

Objectives

To review the Computed Tomography( CT )features of pediatric oncological patients with abdominal and pelvic tumours and correlate these findings with their histopathological diagnosis.

Design

This was a retrospective cross-sectional facility-based study.

Setting

This study was conducted in the Pediatric Oncology Unit and Radiology Department of the Korle Bu Teaching Hospital.

Participants

Fifty-six pediatric oncology patients with contrast-enhanced abdominal and pelvic CT scans.

Data Collection

The abdominal and pelvic CT scans findings, patient biodata, and histopathology reports of oncology patients over four years were reviewed.

Statistical analysis

Simple descriptive statistics using frequency distribution, percentages, means, and standard deviation were used to describe the various variables and presented tables.

Results

The four commonest tumours were nephroblastoma, neuroblastoma, lymphoma, and hepatoblastoma. The mean age at diagnosis was 4.8 years, with a slightly higher male predominance. The majority of the tumours were extremely large at presentation. Overall, the CT - histopathology concordance was 79.2%.

Conclusion

Abdominal and pelvic CT scans play an important role in the diagnostic workup of pediatric malignancies by ensuring early and accurate diagnosis of these tumours.

Funding

None declared.

Wilms tumor

The objectives for the treatment of Wilms tumor in both the Children's Oncology Group (COG) and the International Society of Paediatric Oncology (SIOP) have focused on improving cure rates and minimizing toxicity by limiting the use of radiation and doxorubicin. Although the timing of surgery is different in COG (upfront surgery) and SIOP (upfront chemotherapy with delayed surgery), both are effective strategies and have the same survival. Fewer patients are treated with radiotherapy in the SIOP trials but with higher doses. The prognostic significance of biological markers such as 1q gain and clinical outcomes with novel radiation techniques such as intensity modulated radiation therapy will be determined in upcoming clinical trials. A closer collaboration between COG and SIOP could help promote research and improve the clinical outcomes of children with Wilms tumor.

Agreement between clinicoradiological signs at diagnosis and radiohistological analysis after neoadjuvant chemotherapy of suspected Wilms tumor rupture: Consequences on therapeutic choices

INTRODUCTION

According to SIOP criteria, every patient presenting with preoperative Wilms tumor (WT) rupture must receive abdominal radiotherapy. Neoadjuvant chemotherapy reduces tumor volume and is responsible for the development of peritumoral capsule formation, which can mask tumor rupture on histological analysis, while it was clinically or radiologically obvious at diagnosis. Yet, there are no protocol recommendations for this particular presentation.

OBJECTIVES

Study the agreement between clinicoradiological signs and histological confirmation after neoadjuvant chemotherapy of suspected WT rupture and describe the therapeutic choices arising in consequence.

METHODS

Descriptive retrospective study on a monocentric series of patients with WT between June 1991 and August 2017.

RESULTS

Out of 71 patients, 28 presented with suspected tumor rupture. We observed good agreement between clinical and radiological signs of suspected rupture (κ coefficient: 0.67). However, we assessed poor agreement between these signs and histological conclusions after neoadjuvant chemotherapy (κ coefficient: 0.27). Only five patients with clinicoradiological signs were overtreated with radiotherapy while tumor rupture had been refuted after histological review. The notion of abdominal trauma and the presence of intraperitoneal effusion seemed to guide collegial decision to overtreat these patients. No statistical difference in survival between patients with and without suspicion of tumor rupture at diagnosis was observed.

CONCLUSION

This study highlights the need for recommendations in case of discrepancy between radiological and histological signs of rupture at diagnosis and after neoadjuvant chemotherapy. A study with stronger statistical power is necessary to define criteria that would lead to optimization of treatment in this context.

Evaluation of boost irradiation in patients with intermediate-risk stage III Wilms tumour with positive lymph nodes only: Results from the SIOP-WT-2001 Registry

OBJECTIVE

To evaluate the value of radiotherapy boost omission in patients with intermediate-risk, stage III Wilms tumours (WT) with positive lymph nodes (LN).

METHODS AND MATERIALS

All patients with intermediate-risk, stage III (LN positive) WT consecutively registered in the SIOP-WT-2001 study were included in this analysis. Endpoints were 5-year event-free survival (EFS), loco-regional control (LRC) and overall survival (OS).

RESULTS

Between June 2001 and May 2015, 2,569 patients with stage I to III WT after preoperative chemotherapy were registered in the SIOP-WT-2001 study. Five hundred and twenty-three (20%) had stage III disease, of which 113 patients had stage III due to positive LN only. Of those, 101 (89%) received radiotherapy, 36 of which (36%) received, apart from flank irradiation, a boost dose to the LN positive area. Four patients (4%) did not receive any adjuvant radiotherapy. In eight patients information on radiotherapy was not available. With a median follow-up of 71 months, no difference in 5-year EFS (84% vs. 83%, P = 0.77) and LRC (96% vs. 97%, P = 0.91) was observed between patients receiving a radiotherapy boost and those without boost, respectively. Five-year OS, including salvage therapy, was excellent (boost vs. no boost: 97% vs. 95%, P = 0.58).

CONCLUSIONS

Outcome data demonstrate that omission of the radiotherapy boost to the loco-regional positive lymph nodes in patients with intermediate-risk, stage III WT who receive preoperative chemotherapy and postoperative flank irradiation (14.4 Gy) can be considered a safe approach for future SIOP protocols.

Position paper: Rationale for the treatment of Wilms tumour in the UMBRELLA SIOP-RTSG 2016 protocol

The Renal Tumour Study Group of the International Society of Paediatric Oncology (SIOP-RTSG) has developed a new protocol for the diagnosis and treatment of childhood renal tumours, the UMBRELLA SIOP-RTSG 2016 (the UMBRELLA protocol), to continue international collaboration in the treatment of childhood renal tumours. This protocol will support integrated biomarker and imaging research, focussing on assessing the independent prognostic value of genomic changes within the tumour and the volume of the blastemal component that survives preoperative chemotherapy. Treatment guidelines for Wilms tumours in the UMBRELLA protocol include recommendations for localized, metastatic, and bilateral disease, for all age groups, and for relapsed disease. These recommendations have been established by a multidisciplinary panel of leading experts on renal tumours within the SIOP-RTSG. The UMBRELLA protocol should promote international collaboration and research and serve as the SIOP-RTSG best available treatment standard.

Is Pre-operative Chemotherapy Desirable in all Patients of Wilms' Tumor?

The timing and role of chemotherapy in the management of Wilms' tumor has long been the matter of debate, with different groups showing equally comparable and encouraging results. Over the last decade, however, both the ideol-ogies seem to be converging and the attempt has been to identify groups benefitting with pre-operative chemotherapy, as well as those, where upfront resection should be attempted. In this article authors intend to discuss pros and cons of both the strategies and their applicability in a resource poor setting in developing countries like India.

Malignant rhabdoid tumor of the liver presented with initial tumor rupture

Malignant rhabdoid tumor (MRT) of the liver is a rare, highly aggressive tumor of early childhood. We report a 6-month-old boy who was diagnosed with MRT of the liver and presented with spontaneous tumor rupture. The patient underwent intensified chemotherapy and a radical surgical procedure. Twenty four months from the time of the diagnosis, he is alive without evidence of disease. This is the second report of prolonged survival after initial rupture of hepatic MRT.

Detection of preoperative wilms tumor rupture with CT: a report from the Children's Oncology Group

PURPOSE

To retrospectively determine the diagnostic performance of computed tomography (CT) in identifying the presence or absence of preoperative Wilms tumor rupture.

MATERIALS AND METHODS

The cohort was derived from the AREN03B2 study of the Children's Oncology Group. The study was approved by the institutional review board and was compliant with HIPAA. Written informed consent was obtained before enrollment. The diagnosis of Wilms tumor rupture was established by central review of notes from surgery and/or pathologic examination. Seventy Wilms tumor cases with rupture were matched to 70 Wilms tumor controls without rupture according to age and tumor weight (within 6 months and 50 g, respectively). CT scans were independently reviewed by two radiologists, and the following CT findings were assessed: poorly circumscribed mass, perinephric fat stranding, peritumoral fat planes obscured, retroperitoneal fluid (subcapsular vs extracapsular), ascites beyond the cul-de-sac, peritoneal implants, ipsilateral pleural effusion, and intratumoral hemorrhage. All fluids were classified as hemorrhagic or nonhemorrhagic by using a cutoff of 30 HU. The relationship between CT findings and rupture was assessed with logistic regression models.

RESULTS

The sensitivity and specificity for detecting Wilms tumor rupture were 54% (36 of 67 cases) and 88% (61 of 69 cases), respectively, for reviewer 1 and 70% (47 of 67 cases) and 88% (61 of 69 cases), respectively, for reviewer 2. Interobserver agreement was substantial (ĸ = 0.76). All imaging signs tested, except peritoneal implants, intratumoral hemorrhage, and subcapsular fluid, showed a significant association with rupture (P ≤ .02). The attenuation of ascitic fluid did not have a significant correlation with rupture (P = .9990). Ascites beyond the cul-de-sac was the single best indicator of rupture for both reviewers, followed by perinephric fat stranding and retroperitoneal fluid for reviewers 1 and 2, respectively (P < .01).

CONCLUSION

CT has moderate specificity but relatively low sensitivity in the detection of preoperative Wilms tumor rupture. Ascites beyond the cul-de-sac, irrespective of attenuation, is most predictive of rupture.

Imaging in unilateral Wilms tumour

Wilms tumour is one of the most common malignancies in children, with an excellent prognosis after therapy. There is a very diverse approach to treatment according to geographical location. This variation in therapeutic attitude toward Wilms tumour, particularly between the United States and Europe, has consequences for the choice of imaging modality at diagnosis. In Europe, the International Society of Paediatric Oncology (SIOP) treatment protocol is based on chemotherapy followed by surgery. Imaging (US, CT and MRI), clinical history and examination will help predict whether the findings are consistent with Wilms tumour. Furthermore, in the UK preoperative image-guided biopsy is advised to help identify the small group of patients who, despite typical imaging features of Wilms tumour, have other types of neoplasia that require alternative management. In the United States, the National Wilms Tumor Study (NWTS) advises surgery prior to chemo- and radiotherapy. Hence imaging must provide detailed anatomical information for surgical planning. This article discusses the role of imaging at diagnosis and the relative strengths and weaknesses of the available radiological techniques. We also focus on imaging the lung for metastatic disease and the consequences (to the patient's ultimate outcome) of CT-diagnosed small pulmonary nodules and discuss the radiological diagnosis and consequences of tumour rupture present at diagnosis.

Wilms' tumor: long-term results from a single institution

One-hundred-twelve children with pathological diagnosis of Wilms' tumor were treated during the period 1979-1989. They were postoperatively staged as follows: stage I, 25 patients; stage II, 27 patients; stage III, 48 patients; and stage IV, 9 patients. Three patients were preoperatively classified as stage V. The National Wilms' Tumor Study (NWTS) staging system was used. Except for Stage V patients, the treatment regimen consisted of nephrectomy followed by radiotherapy and/or chemotherapy according to stage of disease and pathology. Stage I, II, and III patients with favorable histology enjoyed 94 +/- 6%, 86 +/- 8%, and 71 +/- 8% 10-year actuarial survival, respectively. Stage IV patients and those in stages I, II, and III with unfavorable histology had a 10-year actuarial survival of 36 +/- 8%. Univariate analyses proved that NWTS stages affected the 10-year actuarial disease-free survival rates but not the overall survival rates. The histopathology significantly affected the disease-free survival and the overall survival rates both in the whole group of patients and in each stage when considered separately. The same histopathology also affected the incidence of development of distant relapse but not the local recurrence rate. On the other hand, massive tumor rupture at surgery increased the incidence of local relapse but not of distant metastasis and did not affect the overall survival rates. The presence of residuum after surgery had nearly the same effect as tumor rupture on the local recurrence. It also did not increase significantly the distant relapse incidence, but it affected significantly the overall survival. Retroperitoneal lymph node involvement had a similar effect. It increased the incidence of local relapse and decreased the 10-year overall survival rate but it had a borderline effect on development of distant metastasis (P = 0.06). The age at diagnosis had also a borderline effect on disease-free survival but it had not effect, of statistical significance, on the overall survival.

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.

Response rates in relapsed Wilms' tumor. A need for new effective agents

Three hundred eighty-one children with Wilms' tumor were treated in the United Kingdom Children's Cancer Study Group WT1 Study (1982 to 1986). Seventy-one patients had relapses during or after treatment with surgery and chemotherapy, and radiation therapy, depending on stage and histologic characteristics. Forty-nine patients were evaluable for disease response to second-line chemotherapy alone. Evaluation of response to chemotherapy was impossible in the remaining patients because either surgery or radiation therapy was used at the time of relapse. With second-line combination chemotherapy (which included ifosfamide, etoposide/VM26, cisplatin/carboplatin, bleomycin, melphalan, and Thiotepa [Lederle Laboratories, Pearl River, NY]), there were five complete responses and 12 partial responses. In patients with favorable histologic findings, six of nine with Stage I, five of ten with Stage II, none of 11 with Stage III, three of 16 with Stage IV, and one of five with Stage V disease survived. Two survivors were treated with chemotherapy alone; the others received combined treatment with chemotherapy, radiation therapy, and/or surgery. For those with unfavorable histologic findings of any stage, only two of 20 survived. The authors conclude that, even for patients with localized disease with favorable histologic findings, the "salvage" rate is little more than 50%, and for all other stages and histologic findings the likelihood of cure after relapse is remote. There is clearly a need for additional effective chemotherapeutic agents for these patients.

Wilms' tumor: reduced-dose radiotherapy in advanced-stage Wilms' tumor with favorable histology

Fifty-two children with favorable histology Wilms' tumor who had residual abdominal disease (Surgical Stages III and IV) were treated from 1979 to 1988 on a protocol designed to assess the effectiveness of reduced radiation doses. All patients received three-agent chemotherapy, beginning within 1 week after surgery. To permit assessment of disease response to initial chemotherapy, radiation therapy was delayed for a median of 28 days after surgery (range, 14-71 days). Total doses of abdominal radiation were limited to 12 Gy, given as 150 cGy daily fractions; 18 patients with Stage IV disease received 12 Gy bilateral pulmonary irradiation. Two year disease-free survival was 85% and 71% for Stage III and IV, respectively (p = .24). Abdominal relapses occurred in 3 cases (5.7%). The interval between surgery and initiation of irradiation was not related to disease-free survival. Of several patient and disease-related factors analyzed, only patient age was related to outcome. Disease-free survival was 100% at 3 years for children under the age of 3 versus 78% for children greater than age 3 (p = .05). Reduced-dose abdominal radiotherapy in conjunction with multi-agent chemotherapy and surgery provided excellent disease control with minimal toxicity in advanced-stage, favorable histology Wilms' tumor.

How curable is relapsed Wilms' tumour? The United Kingdom Children's Cancer Study Group

Three hundred and eighty one children with Wilms' tumour were treated on the United Kingdom Children's Cancer Study Group WT1 Study (1980/6). Seventy one patients relapsed during or after treatment, which included surgery and chemotherapy, with irradiation depending on stage and histology. Despite treatment with various combinations of chemotherapy, surgery, and radiotherapy there were only 17 survivors. For unfavourable histology, any stage, only two of 20 survive. We conclude that, after relapse, even for patients who have had localised disease and favourable histology, the 'salvage' rate is little more than 50% and for all others the likelihood of cure is very small. Three of 41 children who relapsed less than 12 months from diagnosis survive, compared with 14 of 30 who relapsed later. It is essential that even with this 'good prognosis' tumour initial treatment is optimal and given by centres experienced in management of children's cancer. Furthermore, there is a clear need for additional effective chemotherapeutic agents for relapsed patients.

[Recurrence of Wilm's tumor following a 9-year disease-free interval]

We report the case of a 25-year old female patient, who presented with intrapulmonary metastases of a Wilms' tumor nine and a half year after initial therapy of a stage I tumor with surgery, local radiation and combined chemotherapy. In general, relapses of Wilms' tumor occur within two year after nephrectomy. Recurrences after more than 7 years are very rare. A relapse of a Wilms' tumor in an adult patient after more than 9 years is not yet published. We treated our patient according to the therapeutic procedure, which is recommended by the National Wilms' Tumor Study as curative treatment of relapses in childhood: complete resection of pulmonary metastases, irradiation of the whole lunge and repeatingly combined chemotherapy with actinomycin D and vincristin. The patient is doing well without evidence of tumor 13 months after thoractomy. A short review of the literature is given.