Pediatric renal cell carcinoma

Renal cell carcinoma in the pediatric population: A case report and review of the literature

Renal cell carcinoma is a cancer thought to originate from renal epithelial cells. Commonly seen in patients older than 60 years of age, renal cell carcinoma presents as rare pathological entity seen in urological cancers among the pediatric population. A 17-year-old female patient presented with complaints of intermittency, dysuria, and gross hematuria. Radiological imaging was in favor of a left renal mass. Under general anesthesia, the left kidney was completely laparoscopically resected and sent to pathology, which along with correlating the age group of the patient and the morphology on pathological analysis, was suggestive of microphthalmia family translocation renal cell carcinoma.

Clear Cell Renal Cell Carcinoma, Diagnostic and Therapeutic Difficulties, Case Report and Literature Review

Nephroblastoma is the most common kidney tumour in children, constitutes about 85% of cases. Although renal cell carcinoma (RCC) is the second-most common kidney malignancy in children, it constitutes only about 2–6% of all cases. Currently, the basis of children’s RCC treatment is Umbrella Protocol of SIOP-RTSG, but, due to the rare diagnosis of this neoplasm in children, in difficult cases, treatment is based on the experience in adult patients with RCC. Nephrectomy improves prognosis and is usually performed at the first step of treatment. Acute kidney injury secondary to urolithiasis in a patient after nephrectomy due to RCC is a unique, very serious complication. Study design: We present a case of a 10-year-old boy with metastatic clear cell renal cell carcinoma (ccRCC) of the right kidney and an acute renal failure of the left kidney secondary to uric acid nephrolithiasis. Partial regression of the spread of ccRCC after 12.5-month treatment with sunitinib, followed by progression being observed and satisfactory effects and tolerance of nivolumab were observed later. Comorbidity of acute kidney injury during nephrolithiasis and ccRCC after nephrectomy in children is unique. Drugs used in the treatment clear cell carcinoma in adults (sunitinib and nivolumab), are also used in children with ccRCC.

Renal cell carcinoma in children and adolescents: A retrospective study of a French-Italian series of 93 cases

BACKGROUND

Renal cell carcinomas represent 2 to 5% of kidney malignancies in children and adolescents. Appropriate diagnostic and classification are crucial for the correct management of the patients and in order to avoid inappropriate preoperative chemotherapy, which is usually recommended if a Wilms tumor is suspected.

METHODS

a French-Italian series of 93 renal cell carcinomas collected from 1990 to 2019 in patients aged less than 18 years old was reclassified according to the 2016 WHO classification and the latest literature. TFE3 and TFEB FISH analyses and a panel of immunohistochemical stains were applied.

RESULTS

The median age at diagnosis was 11 years (range: 9 months - 17 years). MiT family (MiTF) translocation renal cell carcinomas accounted for 52% of the tumors, followed by papillary renal cell carcinomas (20%) and unclassified renal cell carcinomas (13%). Other subtypes, such as SDHB-deficient and Fumarate hydratase-deficient renal cell carcinomas, represented 1 to 3% of the cases. We also described a case of ALK-rearranged renal cell carcinoma with a metanephric adenoma-like morphology.

CONCLUSION

A precise histological diagnosis is mandatory as targeted therapy could be applied for some RCC subtypes, i.e., MiTF-translocation and ALK-translocation renal cell carcinomas. Moreover, some RCC subtypes may be associated with a predisposition syndrome that will impact patients' and family's management and genetic counseling. A precise RCC subtype is also mandatory for the clinical management of the patients and the inclusion in new prospective clinical trials.

Renal cell carcinoma in a duplex kidney in pediatric

Renal cell carcinoma (RCC) in children is relatively uncommon, especially in the absence of syndromes or hereditary diseases. Duplex kidney - as a common congenital anomalies in children - is usually insignificant with no serious impact or known risk of tumor association. Herein, we report a 5-year-old girl who presented with gross hematuria and a right renal mass in duplex system identified on computed tomography. Radical nephrectomy was performed; the patient was diagnosed with Xp11 translocation RCC and no other modalities of treatments were needed over 3-month follow-up.

Minimally invasive radical nephrectomy: a contemporary review

Minimally invasive renal surgery has revolutionized the surgical management of renal cancer since the initial report of laparoscopic nephrectomy in 1991. Laparoscopic nephrectomy became the mainstay of management in surgically resectable renal masses since the 1990s. The growing body of literature supporting nephron-sparing surgery over the last two decades has meant that minimally invasive radical nephrectomy (MI-RN) is now the preferred treatment for renal tumors not amenable to partial nephrectomy. While there is a well-described experience with complex radical nephrectomy using standard laparoscopy, robot-assisted surgery has shortened the learning curve and facilitated greater uptake of minimally invasive surgery in difficult surgical scenarios traditionally performed open surgically. Increased experience and expertise with robot-assisted renal surgery has led to expansion of the indications for MI-RN to include larger masses, locally advanced renal masses invading adjacent tissues or regional hilar/retroperitoneal lymph nodes, cytoreductive nephrectomy (CN) in metastatic disease, and concurrent venous tumor thrombectomy for renal vein or inferior vena cava (IVC) involvement. In this article, we review the various surgical techniques and adjunctive procedures associated with MI-RN.

A prospective study of pediatric and adolescent renal cell carcinoma: A report from the Children's Oncology Group AREN0321 study

BACKGROUND

To the authors' knowledge, AREN0321 is the first prospective clinical study of pediatric and adolescent renal cell carcinoma (RCC). Goals of the study included establishing epidemiological, treatment, and outcome data and confirming that patients with completely resected pediatric RCC, including lymph node-positive disease (N1), have a favorable prognosis without adjuvant therapy.

METHODS

From 2006 to 2012, patients aged <30 years with centrally reviewed pathology of RCC were enrolled prospectively.

RESULTS

A total of 68 patients were enrolled (39 of whom were male; median age of 13 years [range, 0.17-22.1 years]). Stage was classified according to the American Joint Committee on Cancer TNM stage seventh edition as stage I in 26 patients, stage II in 7 patients, stage III in 26 patients, and stage IV in 8 patients, and was not available in 1 patient. Sixty patients underwent resection of all known sites of disease, including 2 patients with stage IV disease. Surgery included radical nephrectomy (53 patients [81.5%]), partial nephrectomy (12 patients [18.5%]), and unknown (3 patients [4.4%]). Histology was TFE-associated RCC (translocation-type RCC; tRCC) in 40 patients, RCC not otherwise specified and/or other in 13 patients, papillary RCC in 9 patients, and renal medullary carcinoma (RMC) in 6 patients. Lymph node status was N0 in 21 patients, N1 in 21 patients (tRCC in 15 patients, RMC in 3 patients, papillary RCC in 2 patients, and not otherwise specified and/or other in 1 patient), and Nx in 26 patients. The 4-year event-free survival and overall survival rates were 80.2% (95% CI, 69.6%-90.9%) and 84.8% (95% CI, 75.2%-94.5%), respectively, overall and 87.5% (95% CI, 68.3%-100%) and 87.1% (95% CI, 67.6%-100%), respectively, for the 16 patients with N1M0 disease. Among patients presenting with metastases, 2 of 8 patients (2 of 5 patients with RMC) were alive (1 with disease) at the time of last follow-up, including 1 patient who was lost to follow-up (succinate dehydrogenase deficiency). The predominant RCC subtypes associated with mortality were tRCC and RMC.

CONCLUSIONS

Favorable short-term outcomes can be achieved without adjuvant therapy in children and adolescents with completely resected RCC, independent of lymph node status. A prospective study of patients with tRCC and RMC with M1 or recurrent disease is needed to optimize treatment.

Pediatric Renal Neoplasms:: MR Imaging-Based Practical Diagnostic Approach

Pediatric renal tumors may be malignant or benign. Wilms tumor, the most common malignant pediatric renal tumor, arises sporadically or with various syndromes. Renal cell carcinoma typically presents in older children. Renal clear cell sarcoma and rhabdoid tumor are typically less common, more aggressive, and present in younger children. Benign renal tumors include mesoblastic nephroma, multilocular cystic renal tumor, angiomyolipoma, and metanephric adenoma. Lymphoma and leukemia may secondarily involve the kidney. Although there is overlap in the imaging appearance of several pediatric renal tumors, magnetic resonance characteristics and clinical data narrow the differential diagnosis and suggest a specific diagnosis. This article reviews current MR techniques, as well as the common MR imaging characteristics of malignant and benign pediatric renal neoplasms.

Pediatric renal cell carcinoma

PURPOSE OF REVIEW

To review the presentation, natural history and treatment of renal cell carcinoma in children and young adults with renal cell carcinoma (RCC).

RECENT FINDINGS

Complete resection of lymph nodes at the time of tumor resection can improve clinical outcomes and limit the need for adjuvant chemotherapy. Genetic alterations that lead to translocation tumors are a therapeutic target of receptor tyrosine kinase inhibitors.

SUMMARY

The incidence of RCC increases with age. Unlike adult patients, young patients with RCC present symptomatically and at higher stage and grade. Translocation tumors predominate RCC in children with biologic activity characterized by early spread to lymph nodes with small primary tumors. Preoperative imaging is poorly sensitive for positive lymph nodes; as such, surgeons should have a low threshold for lymph node sampling during tumor resection. Despite the advanced stage at presentation, the prognosis in children is more favorable than their adult counterparts. Complete resection of lymph nodes at the time of surgical resection improves patient prognosis. Chemotherapy targeting the PI3/AKT pathway has demonstrated clinical benefit.

Lymph node imaging of pediatric renal and suprarenal malignancies

Pediatric renal and suprarenal cancers are relatively rare malignancies, but are not without significant consequence to both the patient and caretakers. These tumors are often found incidentally and present as large abdominal masses. Standard of care management involves surgical excision of the mass, but contemporary treatment guidelines advocate for use of neoadjuvant or adjuvant chemotherapy for advanced stage disease, such as those cases with lymph node involvement (LNI). However, LNI detection is based primarily on surgical pathology and performing extended lymph node dissection can add significant morbidity to a surgical case. In this review, we focus on the use and performance of imaging modalities to detect LNI in Wilms’ tumor (WT), neuroblastoma, and pediatric renal cell carcinoma (RCC). We report on how imaging impacts management of these cases and the clinical implications of LNI. A literature search was conducted for studies published on imaging-based detection of LNI in pediatric renal and suprarenal cancers. Further review focused on surgical and medical management of those cases with suspected LNI. Current imaging protocols assisting in diagnosis and staging of pediatric renal and suprarenal cancers are generally limited to abdominal ultrasound and cross-sectional imaging, mainly computed tomography (CT). Recent research has investigated the role of more advance modalities, such as magnetic resonance imaging (MRI) and positron emission tomography (PET), in the management of these malignancies. Special consideration must be made for pediatric patients who are more vulnerable to ionizing radiation and have characteristic imaging features different from adult controls. Management of pediatric renal and suprarenal cancers is influenced by LNI, but the rarity of these conditions has limited the volume of clinical research regarding imaging-based staging. As such, standardized criteria for LNI on imaging are lacking. Nevertheless, advanced imaging modalities are being investigated and potentially represent more accurate and safer options.

Translocation Renal Cell Carcinoma in a Child Previously Treated for Infantile Fibrosarcoma

We report a child who developed a TFE3/Xp11.2 translocation renal cell carcinoma (RCC) when he was 3 years and 3 months old, after previous treatment for infantile fibrosarcoma (IFS). When he was 3 months old, a left axilla mass has been detected, which was tan and solid, was 1.5 cm in greatest dimension, and composed of sheets of spindle cells that was positive for vimentin and fibronectin. Fluorescence in situ hybridization showed positive result in ETV6 gene rearrangements. The final diagnosis was IFS. After surgery and chemotherapy, he remained disease-free until 3 years; later, he was detected to have a tumor in right kidney which measured 2.5 × 2 × 1.5 cm. The tumor comprised clear-cell features that were arranged in papillary and adenoid architecture. The tumor cells were positive for TFE3 and CK. The diagnosis was TFE3/Xp11.2 translocation RCC. Previous research has reported that the radio/chemotherapy for the first tumor might be involved in the pathogenesis of translocation RCC. In our report, this is the first time the IFS is included in the disease spectrum which can cause secondary translocation RCC.

[Renal cell carcinomas in childhood]

BACKGROUND

Renal cell carcinoma is a rare childhood disease. However, it should be considered in the differential diagnosis in the detection of a renal mass.

OBJECTIVES

Incidence and mortality of renal cell carcinomas in childhood. Presentation of clinical symptoms, diagnostics, histology, therapy and course of the disease.

PATIENTS AND METHODS

Evaluation of our own prospective data of a small patient population of 8 patients, as well as discussion of the current literature on this tumor entity.

RESULTS

The average follow-up period was 27 months. Preoperative staging studies showed no metastases. The histologically primary predominant subtype was papillary renal cell carcinoma. Tumor stage and lymph node status were the most important prognostic factors in our study.

CONCLUSIONS

Renal cell carcinoma in childhood is a rare disease whose treatment is challenging and should be performed in an interdisciplinary team. Typical clinical symptoms, as in adults, are absent. The partial nephrectomy should be, if practicable, the surgical treatment of choice. The most important risk factors for survival are tumor stage and lymph node status. Data on adjuvant target therapy for metastatic disease in childhood are lacking. Further prospective, multicenter studies are necessary to generate more information on the biology and course of this disease and to obtain adjuvant treatment options in locally advanced disease.

Pediatric Clear Cell Renal Cell Carcinoma with Pelvicalyceal System Invasion and Contiguous Extension Upto Bladder: Novel and Bizarre Tumor Behaviour

Background

Paediatric renal cell carcinoma (RCC) is a rare neoplasm which differs significantly in its clinico-pathological behaviour from the adult variant. The clear cell variant constitutes a relatively small histological subset of this neoplasm.

Case Report

We present a very unusual, pathologically proven case of clear cell variety of pediatric RCC which showed invasion into the pelvicalyceal system with contiguous extension up to the urinary bladder. Such a novel manifestation of paediatric RCC has not been described previously in literature. A relevant review of literature is included.

Conclusions

The aggressive biological behaviour of the paediatric RCC in our case and the consequent atypical imaging findings are distinctly unusual. These findings may represent a new aggressive variant of this rare neoplasm. The radiologist and clinician should be aware of these novel manifestations of paediatric clear cell RCC.

Practice patterns and outcomes of pediatric partial nephrectomy in the United States: Comparison between pediatric urology and general pediatric surgery

BACKGROUND

In the United States, both pediatric urologists (PUROs) and general pediatric surgeons (GPSs) perform nephrectomies in children, with PUROs performing more nephrectomies overall, most commonly for benign causes. GPSs perform more nephrectomies for malignant causes. We questioned whether the same trends persisted for partial nephrectomy.

OBJECTIVE

We hypothesized that PUROs performed more partial nephrectomies for all causes, including malignancy. Our primary aim was to characterize the number of partial nephrectomies performed by PUROs and GPSs. We also compared short-term outcomes between subspecialties.

STUDY DESIGN

We analyzed the Pediatric Health Information System (PHIS), a database encompassing data from 44 children's hospitals. Patients were ≤18 years old and had a partial nephrectomy (ICD-9 procedure code 554) carried out by PUROs or GPSs between 1 January, 2004 and June 30, 2013. Queried data points included surgeon subspecialty, age, gender, 3M™ All Patient Refined Diagnosis Related Groups (3M™ APR DRG) code, severity level, mortality risk, length of stay (LOS), and medical/surgical complication flags. Data points were compared in patients on whom PUROs and GPSs had operated. Statistical analysis included the Student t test, chi-square test, analysis of covariance, and logistic regression.

RESULTS

Results are presented in the table. While PUROs performed the majority of partial nephrectomies, GPSs operated more commonly for malignancy. For surgeries performed for non-malignant indications, PURO patients had a shorter LOS and lower complication rate after controlling for statistically identified covariates. There was no difference in LOS or complication rate for patients with malignancy.

DISCUSSION

A Pediatric Health Information System study of pediatric nephrectomy demonstrated PUROs performed more nephrectomies overall, but GPSs performed more surgeries for malignancy. The difference was less dramatic for partial nephrectomies (63% GPS, 37% PURO) than for radical nephrectomies (90% GPS, 10% PURO). PUROs performed more partial nephrectomies for benign indications (94% PURO, 6% GPS) at an even greater rate than nephrectomies (88% PURO, 12% GPS). As a national database study, there are a number of inherent limitations: applicability of results to non-participating hospitals, possibility of inaccurate data entry/coding, and lack of data points that would be relevant to the study.

CONCLUSIONS

While most partial nephrectomies in the United States are performed by PUROs, GPSs perform the majority of surgeries for malignancy. There is no difference in LOS or complication rate undergoing nephron-sparing surgery for malignant disease; however, PUROs had a shorter LOS and lower complication rate when operating for benign diseases.

A rare cause of childhood renal cysts: Xp11.2 translocation renal cell carcinoma

Pediatric renal cysts are rare, usually asymptomatic and incidentally detected in children. Cyst associated renal cell carcinoma (RCC) or cystic RCC is extremely rare in children. Bosniak classification system has been accepted for the management of cystic renal masses. Xp11.2 translocation RCC is a recently classified distinct subtype and usually affects children and adolescents. We report the case of a 10-year-old girl with Xp11.2 translocation RCC from a cyst of the right kidney.

An approach to renal masses in pediatrics

Renal masses in children may be discovered during routine clinical examination or incidentally during the course of diagnostic or therapeutic procedures for other causes. Renal cancers are rare in the pediatric population and include a spectrum of pathologies that may challenge the clinician in choosing the optimal treatment. Correct identification of the lesion may be difficult, and the appropriate surgical procedure is paramount for lesions suspected to be malignant. The purpose of this article is to provide a comprehensive overview regarding the spectrum of renal tumors in the pediatric population, both benign and malignant, and their surgical management.

Renal cell carcinoma in children, adolescents and young adults: a National Cancer Database study

PURPOSE

We compared the presentation and outcomes of patients younger than 21 years with renal cell carcinoma and determined risk factors associated with mortality.

MATERIALS AND METHODS

We searched the National Cancer Database for patients diagnosed with renal cell carcinoma between 1998 and 2011. We evaluated patients younger than 30 years with renal cell carcinoma, including clear cell, chromophobe, papillary and not otherwise specified subcategories. We used logistic regression to compare presenting cancer, demographics and treatment variables in patients 0 to 15 years, 15 to 21 years and 21 to 30 years old. Cox regression analysis was used to determine risk factors for mortality in patients younger than 21.

RESULTS

Of 3,658 patients younger than 30 years included in the study 161 were younger than 15 and 337 were 15 to 21 years old. A higher proportion of younger patients had renal cell carcinoma not otherwise specified and papillary histology compared to those 21 to 30 years (p < 0.001). Younger patients presented with higher stage (p < 0.0001), higher grade (p < 0.0001) and larger tumors (p < 0.0001) than those 21 to 30 years. A higher percentage of younger patients underwent lymph node dissection (p < 0.0001) or chemotherapy as first-line treatment (p < 0.0001) compared to those 21 to 30 years. Cox regression analysis demonstrated that stage 4 presentation, government insurance status, nonchromophobic pathology results and not undergoing surgery as first-line treatment were independently associated with increased mortality in patients younger than 21 years.

CONCLUSIONS

Children and adolescents with renal cell carcinoma present with more advanced disease than those 21 to 30 years old. In patients younger than 21 years mortality was associated with the nonchromophobe histological subtype, stage 4 disease, government insurance and not undergoing surgery as first-line therapy.

Adolescent urologic oncology: current issues and future directions

Recent Surveillance Epidemiology and End Results (SEER) data indicate that the annual cancer incidence in adolescents is higher than in children, and is on the rise. However, the amount of attention, research funding, and therapeutic progress made in the adolescent oncology population pales in comparison with that of pediatric oncology. Issues of adolescent oncology have only recently been acknowledged by leaders in the field, and current efforts now focus on raising awareness of this unique patient group. In urology, there have been many gains made in pediatric urologic oncology, most notably in Wilms tumor and genitourinary rhabdomyosarcoma (genitourinary [GU] rhabdomyosarcoma [RMS]); however, there has been little to no progress in the adolescent population. In general, adolescent cancer represents the interface between pediatric and adult oncology. Similarly, adolescent urologic oncology must be approached as a distinct entity because of the unique disease processes, treatment-related comorbidities, and psychosocial issues. This article will serve to review the most pertinent adolescent urologic oncologic diagnoses (testicular germ call malignancy, the second peak of the bimodal age distribution of GU-RMS, and adolescent renal malignancies). Also, we focus on such issues as the therapeutic impact on fertility, radiation exposure during therapy, and surveillance, risk of secondary malignancy, the long-term impact of chemotherapy, and the psychosocial burden of cancer in this population. Lastly, we highlight future directions and the foreseeable obstacles towards achieving the same research and therapeutic success enjoyed in pediatric urologic oncology.

Clear cell, papillary and chromophobe renal cell carcinoma in patients younger than 20 years old: a clinicopathologic study with follow-up

OBJECTIVE

To perform a clinicopathologic study with follow-up on this rare subset of tumors in the pediatric population.

PATIENTS AND METHODS

A search was made through the surgical pathology files of two academic institutions for cases of non-translocation associated renal cell carcinoma in patients younger than 20 years old from 1995 to 2011.

RESULTS

12 cases were identified from 350 pediatric patients with renal tumors (prevalence = 3.4%). The mean age at diagnosis was 11 years (range 1-18 years). The average tumor size was 7.3 cm (range 3.0-15.0 cm). Pathological staging analysis revealed 7/12 (58%) pT1 tumors, 3/12 (25%) pT2 tumors, and 2/12 (17%) pT3 tumors. Lymph node metastasis was present in 3/12 (25%) patients. The majority of tumors 9/12 (75%) were Fuhrman nuclear grade 2, while 3/12 (25%) cases were Fuhrman nuclear grade 3. Tumor necrosis was identified in 5/12 (42%) tumors, and angiolymphatic invasion was identified in 4/12 (33%) tumors; 1 patient developed lung metastasis.

CONCLUSIONS

Pathologic parameters typically associated with poor outcome in adults, including metastasis/high tumor stage, high Fuhrman nuclear grade, angiolymphatic invasion, and tumor necrosis, did not lead to death in any of the patients in our series.

A robotic-assisted laparoscopic approach for pediatric renal cell carcinoma allows for both nephron-sparing surgery and extended lymph node dissection

Partial nephrectomy has been previously reported as safe and effective in appropriately selected children with renal cell carcinoma (RCC). However, there are limited reports of laparoscopic or robotic partial nephrectomy for oncologic surgery in children. Additionally, nodal involvement is common in pediatric RCC, and may present even with small primary tumors. Also, it is suggested that lymph node dissection may provide therapeutic benefit. We present a case of pediatric RCC and demonstrate how the risk of nodal involvement may impact the surgical approach. Robotic-assisted laparoscopy can permit excellent exposure for an oncologically-sound resection, in this case a partial nephrectomy, as well as an extended lymph node dissection.

CT and MRI appearances and radiologic staging of pediatric renal cell carcinoma

BACKGROUND

Renal cell carcinoma (RCC) is an uncommon but noteworthy primary pediatric renal malignancy. There is a paucity of published data regarding the CT/MRI appearances and accuracy of pretreatment radiologic staging of this form of cancer in children.

OBJECTIVE

To review the various CT/MRI appearances of pediatric RCC and assess the accuracy of pretreatment radiologic staging using these imaging modalities.

MATERIALS AND METHODS

Institutional Departments of Pathology and Radiology records were searched from 1995 through 2010 for children (younger than 18 years of age) with RCC. Available pretreatment contrast-enhanced abdominopelvic CT and MRI examinations were reviewed by two radiologists. Pertinent imaging findings were documented by consensus, and correlation was made between radiologic and surgicopathological TNM staging.

RESULTS

Pretreatment imaging studies from 10 RCCs in nine children (four girls and five boys; mean age 12.9 years) were reviewed. The mean size of the primary tumor was 6.2 cm (range, 1.5-12.6 cm). Ninety percent of RCCs demonstrated heterogeneous postcontrast enhancement. Fifty percent of masses had associated hemorrhage, while 40% contained internal calcification. Regarding TNM staging, N staging was correct for 10 of 10 tumors, while M staging was correct for 10 of 10 tumors. Imaging correctly staged only 4 of 10 tumors with respect to T stage. Radiologic and surgicopathological overall staging were concordant for 8 of 10 tumors.

CONCLUSION

Pediatric RCCs typically present as large, heterogeneous masses, and they commonly hemorrhage and contain internal calcification. Radiologic and surgicopathological overall TNM staging are frequently concordant, although radiologic T staging is often incorrect.

Pediatric genitourinary tumors

PURPOSE OF REVIEW

To review the 2009/2010 literature on pediatric genitourinary tumors and highlight the most significant publications.

RECENT FINDINGS

New techniques such as gene expression profiling, PET, nephron-sparing surgery, and stem cell transplantation are being incorporated into contemporary treatments for pediatric patients with genitourinary tumors. Biologic markers are increasingly being used to help with risk stratification of patients. WT1 mutation and 11p15 loss of heterozygosity have been associated with relapse in very low-risk Wilms tumors treated with surgery alone and may help reduce the use of chemotherapy in some children. Discussion continues on the use of fusion gene status to risk stratify alveolar rhabdomyosarcoma. Meta-analysis of the use of high-dose chemotherapy with autologous hematopoetic stem cell rescue in patients with relapsed Wilms tumor and rhabdomyosarcoma suggests that some patients may benefit more from conventional salvage chemotherapy. New agents are needed for patients with high-risk and relapsed disease to improve outcomes.

SUMMARY

In general, the prognosis for patients with pediatric genitourinary tumors is favorable. The elucidation of the molecular abnormalities in these tumors is determining risk stratification, treatment strategies, and candidates for new drug development.

Papillary renal cell carcinoma: report of a rare entity in childhood with review of the clinical management

We present the case of a 9-year-old boy who presents with gross hematuria and is subsequently diagnosed with a papillary (type 1) renal cell carcinoma. Management of renal cell carcinoma in the pediatric population represents a unique challenge, owing to the potential for a genetic predisposition and screening. Herein we discuss novel discoveries with respect to pediatric renal cell carcinoma and their potential impact on screening.

[Renal cell carcinoma in children: Report of a case with lymph node involvement]

Renal cell carcinoma (RCC) in children is rare. This entity has different clinical and biological presentation characteristics from adult RCC. In contrast to Wilms tumor, the efficacy of chemotherapy and radiation therapy in pediatric RCC remains uncertain. Debate continues on the importance of lymph node dissection. The authors present a case of RCC with lymph node involvement in a 12-year-old boy. The treatment was radical nephrectomy and a limited lymphadenectomy. No adjuvant therapy was given. After 13 months of follow-up, there is no evidence of recurrence. This case shows that lymph node involvement (in the absence of distant metastases) is not associated with a poor prognosis in pediatric RCC and that lymphadenectomy in lymph node-positive cases is important.

Renal cell carcinoma in children and adolescents

Although rare in children and adolescents, renal cell carcinomas (RCCs) raise important questions concerning the best treatment approach and accurate pathologic classification. The differences emerging between childhood and adulthood RCC probably prevent any direct generalized application of therapies to children that are validated for adults. The translocation type of RCC, which forms a distinct category characterized by translocations involving Xp11.2 or, less frequently, 6p21, has recently emerged as the predominant type of RCC in children and adolescents, whereas it is rarely diagnosed in adults. This new finding emphasizes how important it is to prospectively classify RCCs in children with standardized 'modern' diagnoses. The standard cornerstone of therapy for RCC in children and adolescents remains radical nephrectomy. Nephron-sparing surgery is currently recommended in adults for selected small-volume tumors, but additional data are needed before this experience can be extensively transferred to the pediatric population. The therapeutic value of complete retroperitoneal lymph node dissection is still controversial, especially in patients without suspected nodal involvement, be they adults or children. The backbone of systemic therapies for adult RCC has recently been changed by the introduction of drugs designed to target tumor-related angiogenesis and signal transduction. It is worth noting that the largest clinical efficacy trials on targeted molecules have been conducted on clear-cell RCC. While targeted drugs have become the standard of care for adult metastatic RCC, there are currently no published reports on their role in children, and their use should be considered for patients with unresectable metastatic or advanced-stage RCC. On the other hand, the utility of targeted therapies in the adjuvant setting remains to be seen for both adults and children.

Transcription factor E3 and transcription factor EB renal cell carcinomas: clinical features, biological behavior and prognostic factors

PURPOSE

Translocation renal cell carcinomas represent a distinct clinicopathological entity. Studying the natural history, biological behavior and potential prognostic factors are crucially warranted.

MATERIALS AND METHODS

We selected 54 patients with renal cell carcinoma with positive nuclear transcription factor E3 and transcription factor EB expression from the Juvenile RCC Network. Recurrence-free survival and overall survival were assessed.

RESULTS

Median patient age was 24 years (range 1 to 64) and the male-to-female ratio was 1:1.4. At diagnosis 35 patients (65%) had local disease while 19 (35%) presented with distant metastases. The latter patients were older (median age 36 years) and predominantly male (male-to-female ratio 2) whereas the former group had a median age of 16 years and a male-to-female ratio of 1:2.5. Overall 36 patients underwent complete tumor resection and of these 8 had recurring cancer. On univariate analysis only lymph node involvement and American Joint Committee on Cancer stage were associated with poor recurrence-free survival. When stratified according to lymph node status age 25 years or older was found to predict relapse (p = 0.03). With a median followup of 19.2 months (range 1 to 58) 3-year overall survival was 14.3% in patients with distant metastasis and 70.6% in those without distant metastasis. Distant metastasis developed in the 2 patients with ASPSCR1-TFE3 fusion vs 1 of 11 with other fusion genes.

CONCLUSIONS

Transcription factor E3 and transcription factor EB renal cell carcinoma display different clinical behavior according to gender and age. Lymph node involvement represents the only factor that predicts recurrence. ASPSCR1-TFE3 might be the most aggressive among the transcription factor E3 fusion genes.

A case of renal cell carcinoma after successful treatment of Wilms tumor

This case report documents the eighth reported case of renal cell carcinoma (RCC) occurring after treatment of Wilms tumor. Although secondary malignancies after treatment of Wilms tumors are not infrequent, RCC as the second malignancy is rare. We discuss a 17-year-old girl whose RCC was diagnosed 12.5 years after diagnosis of a Wilms tumor. In addition, we review the literature on the subject. Renal cell carcinoma has been proposed as a consequent of chemoradiation; however, a genetic susceptibility must be considered. Because it is routine to assess the functional status of the remaining solitary kidney by annual ultrasonography, we recommend assessing for the presence of secondary renal malignancies and perhaps continuing routine ultrasounds long-term.

Pediatric genitourinary tumors

PURPOSE OF REVIEW

To review the 2008-2009 literature on pediatric genitourinary tumors and highlight the most significant publications.

RECENT FINDINGS

New techniques such as gene expression profiling, PET, nephron-sparing surgery, and stem cell transplantation are being incorporated into contemporary treatments for pediatric patients with genitourinary tumors. The WTX gene is the most commonly mutated gene in Wilms tumor, and its product enhances Wilms tumor gene 1-mediated transcription. Germline WTX mutations cause an X-linked sclerosing bone dysplasia but do not appear to predispose to Wilms tumor formation. Protocadherin gene clusters on chromosome 5q31 may act as tumor suppressors. In rhabdomyosarcoma, ILK and platelet-derived growth factor receptor-A join the paired box gene 7 and 3-forkhead box O1 fusions as potential therapeutic targets, and muscle-specific microRNAs offer promise as adjuvant therapy. Despite the high cure rate of Wilms tumor, long-term survivors remain at risk of death from various causes.

SUMMARY

In general, the prognosis for patients with pediatric genitourinary tumors is favorable. The elucidation of the molecular abnormalities in these tumors is determining risk stratification, treatment strategies, and candidates for new drug development.

Malignant tumours of the kidney: imaging strategy

Primitive malignant renal tumours comprise 6% of all childhood cancers. Wilms tumour (WT) or nephroblastoma is the most frequent type accounting for more than 90%. Imaging alone cannot differentiate between these tumours with certainty but it plays an important role in screening, diagnostic workup, assessment of therapy response, preoperative evaluation and follow-up. The outcome of WT after therapy is excellent with an overall survival around 90%. In tumours such as those where the outcome is extremely good, focus can be shifted to a risk-based stratification to maintain excellent outcome in children with low risk tumours while improving quality of life and decreasing toxicity and costs. This review will discuss the imaging issues for WT from the European perspective and briefly discuss the characteristics of other malignant renal tumours occurring in children and new imaging techniques with potential in this matter.

Pediatric non-Wilms renal tumors: subtypes, survival, and prognostic indicators

BACKGROUND

To determine the outcomes and predictors of survival for pediatric non-Wilms renal tumors (NWRT).

METHODS

The SEER database (1973-2005) was queried for all patients < 20 y of age.

RESULTS

Overall, 349 cases of NWRT were identified. The major histologic groups included renal cell carcinoma (RCC) (44%), clear cell sarcoma of the kidney (CCSK) (17%), and malignant rhabdoid tumor (MRT) (12%). A bimodal age distribution was observed, with tumors commonly presenting in patients ≤4 y of age and ≥15 y of age. More than 50% of RCC presented at ≥15 y of age, whereas ≥80% of CCSK or MRT patients were ≤4 y of age. Most RCC (57%) and CCSK (53%) were locally staged while most MRT presented with distant disease (51%, P < 0.001). Overall 10-y survival was 63% with improved survival observed in patients with CCSK (79%) and RCC (70%) versus MRT (29%, P < 0.001). By univariate analysis, surgical resection was associated with improved overall 10-y survival (68% versus 30%, P < 0.001), while no benefit was observed for radiotherapy (60% versus 63%, P = 0.8). By multivariate analysis, worse overall survival was observed for patients ≥ 10 y old (HR 4.01, P = 0.013) and those with advanced disease (HR = 12.78, P < 0.001). Patients with MRT (HR = 11.61, P < 0.001) and CCSK (HR = 3.68, P = 0.038) had significantly worse prognosis compared with those with RCC. Surgical resection improved overall survival (HR = 0.36, P = 0.001).

CONCLUSION

For pediatric NWRT, younger patients and those with RCC have improved survival, while a diagnosis of MRT portends a worse prognosis. Surgical extirpation significantly improves survival for all patients.