Prognostic significance of age in 5631 patients with Wilms tumour prospectively registered in International Society of Paediatric Oncology (SIOP) 93-01 and 2001

BACKGROUND

To enhance risk stratification for Wilms tumour (WT) in a pre-operative chemotherapy setting, we explored the prognostic significance and optimal age cutoffs in patients treated according to International Society of Paediatric Oncology Renal Tumour Study Group (SIOP-RTSG) protocols.

METHODS

Patients(6 months-18 years) with unilateral WT were selected from prospective SIOP 93-01 and 2001 studies(1993-2016). Martingale residual analysis was used to explore optimal age cutoffs. Outcome according to age was analyzed by uni- and multivariable analysis, adjusted for sex, biopsy(yes/no), stage, histology and tumour volume at surgery.

RESULTS

5631 patients were included; median age was 3.4 years(IQR: 2-5.1). Estimated 5-year event-free survival (EFS) and overall survival (OS) were 85%(95%CI 83.5-85.5) and 93%(95%CI 92.0-93.4). Martingale residual plots detected no optimal age cutoffs. Multivariable analysis showed lower EFS with increasing age(linear trend P<0.001). Using previously described age categories, EFS was lower for patients aged 2-4(HR 1.34, P = 0.02), 4-10(HR 1.83, P<0.0001) and 10-18 years(HR 1.74, P = 0.01) as compared to patients aged 6 months-2 years. OS was lower for patients 4-10 years(HR 1.67, P = 0.01) and 10-18 years(HR 1.87, P = 0.04), but not for 2-4 years(HR 1.29, P = 0.23). Higher stage, histological risk group and tumour volume were independent adverse prognostic factors.

CONCLUSION

Although optimal age cutoffs could not be identified, we demonstrated the prognostic significance of age as well as previously described cutoffs for EFS (2 and 4 years) and OS (4 years) in children with WT treated with pre-operative chemotherapy. These findings encourage the consideration of age in the design of future SIOP-RTSG protocols.

[Solid pediatric tumors : A brief survey of the rarity cabinet]

Solid tumors in childhood are extremely rare entities, which are usually treated in specialized centers. Diagnosis and therapy are carried out according to a joint European protocol, whereby the pathological evaluation and therapy are carried out according to international guidelines. For the correct diagnosis and/or therapy of most tumors, analysis of specific genetic changes is mandatory; therefore, tumors have to be adequately sampled for parallel genetic analysis during the pathological work-up. A second opinion reference of the histopathological assessment is part of the international guidelines. Neuroblastomas, congenital mesoblastic nephromas and rhabdoid tumors are examples of solid tumors in childhood that are not restricted to one organ and occur exclusively during childhood.

Treatment of relapsed Wilms tumour (WT) patients: experience with topotecan. A report from the SIOP Renal Tumour Study Group (RTSG)

BACKGROUND

Topotecan has been variably incorporated in the treatment of patients with relapsed Wilms tumour (WT) who failed initial treatment with three or more effective drugs. Our objective was to describe outcome and to retrospectively investigate the potential role of topotecan in relapsed WT patients.

METHODS

Children who were treated with topotecan as part of their chemotherapeutic regimens for relapsed WT were identified and included in our retrospective study. Patient charts were reviewed for general patient characteristics, histology and stage at initial diagnosis, number and type of relapse, salvage treatment schedules, toxicity, response to treatment and outcome.

RESULTS

From 2000 to 2012, 30 children (median age at relapse 5.5 years, range 1.6-14.5 years) were identified to have received topotecan as part of their salvage regimens (primary progressive disease n = 3, first, second and third relapse n = 13, 9 and 2 respectively, partial response n = 3). Topotecan was administered as a single agent (12 patients) or in combination with other drugs (18 patients). Sixteen patients had high-risk histology according to the SIOP classification, 15 died within 12 months because of progressive disease. Fourteen patients had SIOP intermediate-risk histology of which four patients displayed objective responses to topotecan. Overall, 6 out of 14 intermediate-risk patients survived (median follow up of 6 years), however, three of whom (stage V) had bilateral nephrectomy after topotecan treatment.

CONCLUSIONS

Topotecan does not seem to show effectiveness in the treatment of relapsed WT patients with initial high-risk histology. In patients with intermediate-risk histology, the role of topotecan might deserve further attention, to prove its efficacy.

Risk factors for local recurrence in Wilms tumour and the potential influence of biopsy - the United Kingdom experience

RATIONALE

The UKW3 trial compared biopsy/pre-operative chemotherapy versus immediate nephrectomy and afforded the opportunity to examine the influence of percutaneous retroperitoneal biopsy and other factors on local and distant relapse of Wilms tumour (WT).

METHODS

Patients with unilateral WT (stages I-IV) excluding metachronous relapse or early progressive disease were eligible. Metastatic and 'inoperable' tumours were biopsied electively. 'Local' was defined as relapse within the abdomen, except for liver metastases considered as 'distant' relapse, together with other haematogenous routes. Uni- and multivariable analyses estimated the risk factors for relapse.

RESULTS

Overall, 285/635 (44.9%) patients had a biopsy. With a median follow-up of 10.1 years, 35 (5.5%) patients experienced a 'local', 15 a combined (2.4%) and 60 (9.4%) a 'distant' relapse. On univariate analysis, biopsy, anaplasia and tumour size were associated with an increased risk of local relapse. On multivariable analysis, anaplasia and tumour size remained significant for local relapse whereas the elevated risk of biopsy (hazards ratio (HR) = 1.80: 95% confidence interval (CI) 0.97-3.32, p = 0.060) was marginal. Age, anaplasia, tumour size, lymph nodes metastases and stage, but not biopsy, were individually associated with increased risk of distant relapse but only age and anaplasia remained significant following multivariable analysis.

CONCLUSIONS

The UKW3 trial provides some reassurance that biopsy should not automatically lead to 'upstaging' of WT. Further assessment of this controversial area is required. Comparison of local relapse rates in a multinational trial in which the United Kingdom (UK) continued the practice of routinely biopsying all patients in contrast to the standard European approach will afford this opportunity and is planned.

Gain of 1q is a marker of poor prognosis in Wilms' tumors

Wilms' tumor (WT) trials aim to better tailor treatment intensity to the risk of relapse and death. Currently, stage, histology, age (< or > 24 months), and combined loss of heterozygosity at 1p and 16q in chemotherapy-naïve WTs are the only risk factors used for treatment stratification. However, they predict only less than one-third of all relapsing patients, implying that other factors are involved in treatment failure. Previous studies have associated 1q gain with adverse outcome. Therefore, in this study, the role of 1q gain and other common cytogenetic aberrations (CAs) in WTs was investigated and related to follow-up data from patients with WT treated in the United Kingdom; 19% (64/331) had 1q gain. Gain of 1q was significantly associated with 16q loss (P < 0.001) and 1p loss (P < 0.001). In multivariate analysis taking account of age, tumor stage, anaplasia, and common CA (e.g., 1p loss and 16q loss), 1q gain was independently associated with adverse event-free survival [EFS; hazard ratio (HR) = 2.45, P = 0.02] and overall survival (HR = 4.28, P = 0.004). Loss of 14q was independently associated with an adverse EFS (HR = 4.0, P = 0.04). Gain of 1q is a marker of poor prognosis in WTs, independent of high tumor stage and anaplasia which remain the overarching adverse prognostic factors. Confirmation in other studies is necessary before future therapeutic studies can incorporate 1q gain into new risk stratification schema.

Constitutional translocation breakpoint mapping by genome-wide paired-end sequencing identifies HACE1 as a putative Wilms tumour susceptibility gene

BACKGROUND

Localisation of the breakpoints of chromosomal translocations has aided the discovery of several disease genes but has traditionally required laborious investigation of chromosomes by fluorescent in situ hybridisation approaches. Here, a strategy that utilises genome-wide paired-end massively parallel DNA sequencing to rapidly map translocation breakpoints is reported. This method was used to fine map a de novo t(5;6)(q21;q21) translocation in a child with bilateral, young-onset Wilms tumour.

METHODS AND RESULTS

Genome-wide paired-end sequencing was performed for approximately 6 million randomly generated approximately 3 kb fragments from constitutional DNA containing the translocation, and six fragments in which one end mapped to chromosome 5 and the other to chromosome 6 were identified. This mapped the translocation breakpoints to within 1.7 kb. Then, PCR assays that amplified across the rearrangement junction were designed to characterise the breakpoints at sequence-level resolution. The 6q21 breakpoint transects and truncates HACE1, an E3 ubiquitin-protein ligase that has been implicated as a somatically inactivated target in Wilms tumourigenesis. To evaluate the contribution of HACE1 to Wilms tumour predisposition, the gene was mutationally screened in 450 individuals with Wilms tumour. One child with unilateral Wilms tumour and a truncating HACE1 mutation was identified.

CONCLUSIONS

These data indicate that constitutional disruption of HACE1 likely predisposes to Wilms tumour. However, HACE1 mutations are rare and therefore can only make a small contribution to Wilms tumour incidence. More broadly, this study demonstrates the utility of genome-wide paired-end sequencing in the delineation of apparently balanced chromosomal translocations, for which it is likely to become the method of choice.

Complex patterns of chromosome 9 alterations including the p16INK4a locus in Wilms tumours

BACKGROUND

Previous data implicating genetic and epigenetic events on chromosome 9, including the CDKN2A/2B locus, as molecular predictors of Wilms tumour relapse, have been conflicting.

AIMS

To clarify this using genome-wide and focused molecular genetic analysis.

METHODS

Microarray-based comparative genomic hybridisation (aCGH) using genome-wide coverage was applied to 76 favourable histology Wilms tumours. Additional investigation of the 9p21 locus was carried out using loss of heterozygosity (LOH) and fluorescence in situ hybridisation (FISH), as well as immunohistochemistry for CDKN2A/p16(INK4a) on a paediatric renal tumour tissue microarray.

RESULTS

Approximately half of the tumours were found to show chromosome 9 copy number changes. Those cases which harboured alterations comprised at least four distinct patterns: gain of the entire chromosome, loss of 9p, gain of 9q34, or a more complex combination of gains/losses. None of these tumour groups showed any statistically significant correlation with clinicopathological variables. Deletion mapping of 9p by LOH revealed several regions of overlap, including the CDKN2A/2B locus in 4/34 (11.8%) tumours, which was confirmed to represent hemizygous deletions by FISH. CDKN2A/p16(INK4a) protein expression was predominantly negative in Wilms tumours as assessed by immunohistochemistry on a tissue array, reflecting the expression pattern in normal kidney. However, 38/236 (16.1%) non-anaplastic Wilms tumours, 4/9 (44.4%) anaplastic Wilms tumours, 5/7 (71.4%) rhabdoid tumours of the kidney, and 4/10 (40%) clear cell sarcomas of the kidney showed nuclear CDKN2A/p16(INK4a )immunoreactivity.

CONCLUSIONS

These data reveal the complex nature of genetic alterations on chromosome 9 in Wilms tumours, but do not provide evidence for their involvement in or association with treatment failure.

Older age is an adverse prognostic factor in stage I, favorable histology Wilms' tumor treated with vincristine monochemotherapy: a study by the United Kingdom Children's Cancer Study Group, Wilm's Tumor Working Group

PURPOSE

To identify clinical prognostic factors in children with stage I, favorable histology (FH) Wilms' tumor treated with vincristine monochemotherapy after immediate nephrectomy to define subgroups for consideration of further reduction in treatment intensity.

PATIENTS AND METHODS

During two consecutive trials of the United Kingdom Children's Cancer Study Group (UKW2 and UKW3, 1986 to 2001), 242 children with stage I FH Wilms' tumor were treated with immediate nephrectomy followed by 10 weekly injections of vincristine 1.5 mg/m2. Event-free survival (EFS) and overall survival (OS) were compared by age group.

RESULTS

The 4-year EFS rate was 93.2%, 87.2%, and 71.3% for children less than 2 years old, 2 to 4 years old, and 4 years old or older at diagnosis, respectively (log-rank, P =.001); the corresponding 4-year OS rate was 98.1%, 95.0%, and 87.2% (log-rank, P =.01). There were no toxicity- or procedure-related deaths. In multivariate analysis, specimen weight was not of independent prognostic value (P =.66). Among the 186 children younger than 4 years at diagnosis, there were 17 relapses and five deaths, compared with 16 relapses and eight deaths among the 56 children at least 4 years old at diagnosis. OS after relapse was surprisingly poor (61.6% at 4 years).

CONCLUSION

Treatment for stage I FH Wilms' tumor is generally successful using vincristine monotherapy after immediate nephrectomy, and therefore, the risks of dactinomycin hepatopathy can be avoided. However, age at least 4 years is a significant adverse prognostic factor. This treatment schedule should be considered in any trial of treatment reduction in very young children with stage I FH Wilms' tumor, regardless of tumor size, and we suggest that the upper age limit for the reduced therapy be set at 4 years.

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.

Cholestasis caused by biliary botryoid sarcoma

A 4-year-old boy with a short history of jaundice and hepatomegaly was studied by endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic cholangiography (PTC). A large obstructing choledochal tumour was found at the level of cystic duct insertion and at surgery, a botryoid sarcoma was removed. Subsequent cytotoxic therapy was complicated by persistent dilatation of the extrahepatic bile ducts which necessitated eventual excision. There was no evidence of persistent tumour.