Pediatric urologic oncology: organ-sparing surgery in kidney and testis

Partial orchiectomy vs. radical orchiectomy for pediatric testis tumors

While radical orchiectomy remains the gold standard for testicular cancer, partial orchiectomy has become a well-accepted organ-sparing approach for benign testicular tumors in pre-pubertal patients. The aims of testicular-sparing surgery include prevention of over-treatment, preservation of future hormonal and reproductive function, and provision of a durable cure. For pre-pubertal patients, who have a high likelihood of benign lesions, partial orchiectomy provides effective treatment, owing to the high reliability of scrotal ultrasound (US) and intraoperative frozen section. In adolescent and young adult patients, who are more likely to harbor malignant pathology, the role of partial orchiectomy is less clear. Testis-sparing surgery is being reported with greater frequency in the adult literature for small testicular masses and for situations in which radical orchiectomy would result in an anorchia. More recently, a testis-sparing approach has also been described for carefully-selected post-pubertal pediatric patients. This review will highlight the role of partial orchiectomy in pediatric patients (<18 years old).

Testicular-sparing surgery in the pediatric population: multicenter review of practice with review of the literature

PURPOSE OF REVIEW

Pediatric testicular tumors have predominantly favorable histology, which may permit testicular sparing surgery (TSS). Limited guidance exists for TSS in adults and is absent in pediatric practice.The international survey and retrospective case series evaluated the current use of TSS in pediatric testicular tumors. Alongside the complementary literature review, the aim of this work was to provide evidence that could be used to produce a guideline document.

RECENT FINDINGS

Published evidence advocates small mass size as an indicator for TSS, this was not supported in the pediatric literature. Frozen section examination at TSS was not always performed by surgeons and yet the literature reports close to 100% specificity. Tumor markers and ultrasound findings are also used as indicators for TSS, a finding reflected in our survey results.

SUMMARY

Multiple case series are reported but no large data series exists, which will require international collaboration rather than a drive to publish the results of individual centers. Common indicators for TSS use; such as tumor markers and imaging are known but further work needs to evaluate the role of on-table histology and the risks of this not being available.

Early and late adverse renal effects after potentially nephrotoxic treatment for childhood cancer

BACKGROUND

Improvements in diagnostics and treatment for paediatric malignancies resulted in a major increase in survival. However, childhood cancer survivors (CCS) are at risk of developing adverse effects caused by multimodal treatment for their malignancy. Nephrotoxicity is a known side effect of several treatments, including cisplatin, carboplatin, ifosfamide, radiotherapy and nephrectomy, and can cause glomerular filtration rate (GFR) impairment, proteinuria, tubulopathy, and hypertension. Evidence about the long-term effects of these treatments on renal function remains inconclusive. It is important to know the risk of, and risk factors for, early and late adverse renal effects, so that ultimately treatment and screening protocols can be adjusted. This review is an update of a previously published Cochrane Review.

OBJECTIVES

To evaluate existing evidence on the effects of potentially nephrotoxic treatment modalities on the prevalence of renal dysfunction in survivors treated for childhood cancer with a median or mean survival of at least one year after cessation of treatment, where possible in comparison with the general population or CCS treated without potentially nephrotoxic treatment. In addition, to evaluate evidence on associated risk factors, such as follow-up duration, age at time of diagnosis and treatment combinations, as well as the effect of doses.

SEARCH METHODS

On 31 March 2017 we searched the following electronic databases: CENTRAL, MEDLINE and Embase. In addition, we screened reference lists of relevant studies and we searched the congress proceedings of the International Society of Pediatric Oncology (SIOP) and The American Society of Pediatric Hematology/Oncology (ASPHO) from 2010 to 2016/2017.

SELECTION CRITERIA

Except for case reports, case series and studies including fewer than 20 participants, we included studies with all study designs that reported on renal function (one year or longer after cessation of treatment), in CCS treated before the age of 21 years with cisplatin, carboplatin, ifosfamide, radiation involving the kidney region, a nephrectomy, or a combination of two or more of these treatments. When not all treatment modalities were described or the study group of interest was unclear, a study was not eligible for the evaluation of prevalence. We still included it for the assessment of risk factors if it had performed a multivariable analysis.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, 'Risk of bias' assessment and data extraction using standardised data collection forms. We performed analyses according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

Apart from the remaining 37 studies included from the original review, the search resulted in the inclusion of 24 new studies. In total, we included 61 studies; 46 for prevalence, six for both prevalence and risk factors, and nine not meeting the inclusion criteria, but assessing risk factors. The 52 studies evaluating the prevalence of renal dysfunction included 13,327 participants of interest, of whom at least 4499 underwent renal function testing. The prevalence of adverse renal effects ranged from 0% to 84%. This variation may be due to diversity of included malignancies, received treatments, reported outcome measures, follow-up duration and the methodological quality of available evidence.Seven out of 52 studies, including 244 participants, reported the prevalence of chronic kidney disease, which ranged from 2.4% to 32%.Of these 52 studies, 36 studied a decreased (estimated) GFR, including at least 432 CCS, and found it was present in 0% to 73.7% of participants. One eligible study reported an increased risk of glomerular dysfunction after concomitant treatment with aminoglycosides and vancomycin in CCS receiving total body irradiation (TBI). Four non-eligible studies assessing a total cohort of CCS, found nephrectomy and (high-dose (HD)) ifosfamide as risk factors for decreased GFR. The majority also reported cisplatin as a risk factor. In addition, two non-eligible studies showed an association of a longer follow-up period with glomerular dysfunction.Twenty-two out of 52 studies, including 851 participants, studied proteinuria, which was present in 3.5% to 84% of participants. Risk factors, analysed by three non-eligible studies, included HD cisplatin, (HD) ifosfamide, TBI, and a combination of nephrectomy and abdominal radiotherapy. However, studies were contradictory and incomparable.Eleven out of 52 studies assessed hypophosphataemia or tubular phosphate reabsorption (TPR), or both. Prevalence ranged between 0% and 36.8% for hypophosphataemia in 287 participants, and from 0% to 62.5% for impaired TPR in 246 participants. One non-eligible study investigated risk factors for hypophosphataemia, but could not find any association.Four out of 52 studies, including 128 CCS, assessed the prevalence of hypomagnesaemia, which ranged between 13.2% and 28.6%. Both non-eligible studies investigating risk factors identified cisplatin as a risk factor. Carboplatin, nephrectomy and follow-up time were other reported risk factors.The prevalence of hypertension ranged from 0% to 50% in 2464 participants (30/52 studies). Risk factors reported by one eligible study were older age at screening and abdominal radiotherapy. A non-eligible study also found long follow-up time as risk factor. Three non-eligible studies showed that a higher body mass index increased the risk of hypertension. Treatment-related risk factors were abdominal radiotherapy and TBI, but studies were inconsistent.Because of the profound heterogeneity of the studies, it was not possible to perform meta-analyses. Risk of bias was present in all studies.

AUTHORS' CONCLUSIONS

The prevalence of adverse renal effects after treatment with cisplatin, carboplatin, ifosfamide, radiation therapy involving the kidney region, nephrectomy, or any combination of these, ranged from 0% to 84% depending on the study population, received treatment combination, reported outcome measure, follow-up duration and methodological quality. With currently available evidence, it was not possible to draw solid conclusions regarding the prevalence of, and treatment-related risk factors for, specific adverse renal effects. Future studies should focus on adequate study designs and reporting, including large prospective cohort studies with adequate control groups when possible. In addition, these studies should deploy multivariable risk factor analyses to correct for possible confounding. Next to research concerning known nephrotoxic therapies, exploring nephrotoxicity after new therapeutic agents is advised for future studies. Until more evidence becomes available, CCS should preferably be enrolled into long-term follow-up programmes to monitor their renal function and blood pressure.

Appropriateness for testis-sparing surgery based on the testicular tumor size in a pediatric and adolescent population

INTRODUCTION

In children, most small testicular tumors are benign, and testicular-sparing surgery (TSS) is a viable treatment option.

OBJECTIVE

The objective of this study is to assess for correlation between the tumor size and final pathologic diagnoses appropriate for TSS for pediatric and adolescent patients with an intratesticular mass and negative serum tumor markers (STMs).

MATERIALS AND METHODS

A retrospective review of 24 patients (aged 0-18 years) who underwent radical or partial orchiectomy between 2003 and 2015. Patients with unifocal, unilateral intratesticular tumors and negative STMs were included. Tumors with benign and non-germ cell histology were considered appropriate for TSS, and active germ cell tumor elements on final histology were categorized as inappropriate for TSS. Baseline characteristics, tumor size, and frozen section results were evaluated for association, for the entire cohort and then for a subset of pubertal and postpubertal patients (defined as ≥10 years old).

RESULTS

Patients with testicular tumor pathology inappropriate for TSS were significantly older (median age 17.1 years, P = 0.03). A 2-cm size cutoff did not accurately predict pathology for the entire cohort, or for just pubertal and postpubertal patients (P = 0.132, P = 0.154, respectively). Frozen section and final pathology demonstrated good agreement (κ = 0.826, P < 0.001) as did pre-operative and final pathologic size measurement (κ = 0.703, P < 0.001). Frozen section analysis did not miss a TSS inappropriate pathology.

DISCUSSION

The present data refute the finding in adults that a 2-cm cutoff accurately predicts pathology in pediatric patients with an intratesticular mass and normal STMs. These data suggest that TSS should still be offered, regardless of the tumor size alone, but frozen section appears to more accurately predict pathology than the tumor size, and its use should, thus, be emphasized. There are several limitations of this study to mention. First, this is a retrospective review of a small cohort of patients with a rare clinical scenario, which necessitated the combination of pediatric and adolescent patients. The study did not evaluate oncologic outcomes.

CONCLUSIONS

In children with an intratesticular tumor and normal STMs, a tumor size cutoff of 2 cm does not appear to accurately predict the final pathology. However, the data presented support the continued use intra-operative frozen section analysis in both children and adolescents undergoing TSS.

The role of testis-sparing surgery in children and adolescents with testicular tumors

Organ-sparing approaches have been applied to the treatment of a variety of urologic tumors in both the realms of adult and pediatric urology, with the goals of minimizing overtreatment of benign lesions, preserving function, and providing durable cure. The predominance of benign tumors in prepubertal patients and the reliability of both ultrasound and intraoperative frozen sections have resulted in a marked shift toward testis-sparing approaches over the last few decades. The role of testis sparing in the adolescent population is presently unclear, although there have been increasing reports of successful organ-sparing surgery for testis tumors in the adult literature. This review presents recent trends in testis-sparing approaches for both pediatric and adolescent patients, the operative technique, and some of the controversies related to testis-sparing surgery.

Early and late renal adverse effects after potentially nephrotoxic treatment for childhood cancer

BACKGROUND

Great improvements in diagnostics and treatment for malignant disease in childhood have led to a major increase in survival. However, childhood cancer survivors (CCS) are at great risk for developing adverse effects caused by multimodal treatment for their malignancy. Nephrotoxicity is one of these known (acute) side effects of several treatments, including cisplatin, carboplatin, ifosfamide, radiotherapy and nephrectomy, and can cause glomerular filtration rate impairment, proteinuria, tubulopathy and hypertension. However, evidence about the long-term effects of these treatments on renal function remains inconclusive. To reduce the number of (long-term) nephrotoxic events in CCS, it is important to know the risk of, and risk factors for, early and late renal adverse effects, so that ultimately treatment and screening protocols can be adjusted.

OBJECTIVES

To evaluate existing evidence on the effects of potentially nephrotoxic treatment modalities on the prevalence of and associated risk factors for renal dysfunction in survivors treated for childhood cancer with a median or mean survival of at least one year after cessation of treatment, where possible in comparison with healthy controls or CCS treated without potentially nephrotoxic treatment.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 4, 2011), MEDLINE/PubMed (from 1945 to December 2011) and EMBASE/Ovid (from 1980 to December 2011).

SELECTION CRITERIA

With the exception of case reports, case series and studies including fewer than 20 participants, we included studies with all study designs that reported on renal function (one year or longer after cessation of treatment) in children and adults who were treated for a paediatric malignancy (aged 18 years or younger at diagnosis) with cisplatin, carboplatin, ifosfamide, radiation including the kidney region and/or a nephrectomy.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, risk of bias assessment and data extraction using standardised data collection forms. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

The search strategy identified 5504 studies, of which 5138 were excluded on the basis of title and/or abstract. The full-text screening of the remaining 366 articles resulted in the inclusion of 57 studies investigating the prevalence of and sometimes also risk factors for early and late renal adverse effects of treatment for childhood cancer. The 57 studies included at least 13,338 participants of interest for this study, of whom at least 6516 underwent renal function testing. The prevalence of renal adverse effects ranged from 0% to 84%. This variation may be due to diversity in included malignancies, prescribed treatments, reported outcome measurements and the methodological quality of available evidence.Chronic kidney disease/renal insufficiency (as defined by the authors of the original studies) was reported in 10 of 57 studies. The prevalence of chronic kidney disease ranged between 0.5% and 70.4% in the 10 studies and between 0.5% and 18.8% in the six studies that specifically investigated Wilms' tumour survivors treated with a unilateral nephrectomy.A decreased (estimated) glomerular filtration rate was present in 0% to 50% of all assessed survivors (32/57 studies). Total body irradiation; concomitant treatment with aminoglycosides, vancomycin, amphotericin B or cyclosporin A; older age at treatment and longer interval from therapy to follow-up were significant risk factors reported in multivariate analyses. Proteinuria was present in 0% to 84% of all survivors (17/57 studies). No study performed multivariate analysis to assess risk factors for proteinuria.Hypophosphataemia was assessed in seven studies. Reported prevalences ranged between 0% and 47.6%, but four of seven studies found a prevalence of 0%. No studies assessed risk factors for hypophosphataemia using multivariate analysis. The prevalence of impairment of tubular phosphate reabsorption was mostly higher (range 0% to 62.5%; 11/57 studies). Higher cumulative ifosfamide dose, concomitant cisplatin treatment, nephrectomy and longer follow-up duration were significant risk factors for impaired tubular phosphate reabsorption in multivariate analyses.Treatment with cisplatin and carboplatin was associated with a significantly lower serum magnesium level in multivariate analysis, and the prevalence of hypomagnesaemia ranged between 0% and 37.5% in the eight studies investigating serum magnesium.Hypertension was investigated in 24 of the 57 studies. Reported prevalences ranged from 0% to 18.2%. A higher body mass index was the only significant risk factor noted in more than one multivariate analysis. Other reported factors that significantly increased the risk of hypertension were use of total body irradiation, abdominal irradiation, acute kidney injury, unrelated or autologous stem cell donor type, growth hormone therapy and older age at screening. Previous infection with hepatitis C significantly decreased the risk of hypertension.Because of the profound heterogeneity of the studies, it was not possible to perform any meta-analysis.

AUTHORS' CONCLUSIONS

The prevalence of renal adverse events after treatment with cisplatin, carboplatin, ifosfamide, radiation therapy involving the kidney region and/or nephrectomy ranged from 0% to 84%. With currently available evidence, it was not possible to draw any conclusions with regard to prevalence of and risk factors for renal adverse effects. Future studies should focus on adequate study design and reporting and should deploy multivariate risk factor analysis to correct for possible confounding. Until more evidence becomes available, CCS should be enrolled into long-term follow-up programmes to monitor their renal function and blood pressure.

Oncology: the role of partial nephrectomy in Wilms tumor

Wilms tumor represents the most common pediatric renal malignancy and the fourth most common childhood cancer overall. Overall survival from Wilms tumor has increased to over 90 % secondary to multidisciplinary therapy and multi-institutional cooperative group trials. Recent therapeutic focus has shifted to reduction in treatment morbidity and renal preservation while maintaining the high survival rates. Partial nephrectomy is an integral component of the multimodal treatment protocols for Wilms tumor patients with bilateral disease, solitary kidney, or predisposing syndromes. Recent consideration has been given to utilization of nephron sparing surgery (NSS) in carefully selected patients with nonsyndromic unilateral Wilms tumor. While long-term, prospective data in this subgroup of patients is not yet available, case series demonstrate comparable oncologic outcomes after partial versus radical nephrectomy. The relative rarity of Wilms tumor, especially those amenable to upfront partial nephrectomy, presents a challenge to conducting controlled trials.