Local lymph node involvement in pediatric renal cell carcinoma: a report from the Italian TREP project

Current surgical approaches to pediatric renal tumors

Pediatric renal tumors are among the most common pediatric solid malignancies. Surgical resection is a key component in the multidisciplinary therapy for children with kidney tumors. Therefore, it is imperative that surgeons caring for children with renal tumors fully understand the current standards of care in order to provide appropriate surgical expertise within this multimodal framework. Fortunately, the last 60 years of international, multidisciplinary pediatric cancer cooperative group studies have enabled high rates of cure for these patients. This review will highlight the international surgical approaches to pediatric patients with kidney cancer to help surgeons understand the key differences and similarities between the European (International Society of Pediatric Oncology) and North American (Children's Oncology Group) recommendations.

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, report of a new case

Renal cell carcinoma (RCC) is rare in children and is usually found in late children. We present a case of a 14 year-old boy who presented with right lumbar pain. CT-scan showed a tumor in the upper pole of the right kidney measuring 15 cm. He underwent radical nephrectomy and histopathologic examination revealed RCC. No adjuvant therapy was given. After three years and half, there is no evidence of recurrence.

Pediatric and young adult renal cell carcinoma

Renal cell carcinoma (RCC) is rare in children but is the most common renal tumor in adults. Pediatric RCC has different clinical characteristics, histopathology, and treatment compared with adult disease. Databases were reviewed from inception to February 2020, identifying 32 publications pertaining to 350 patients under 27 years. Surgery is the cornerstone for cure in localized RCC. Lymph node dissection remains controversial. Conventional radiotherapy has no curative role in RCC; similarly, conventional chemotherapy has not proven to be effective in large cohorts. Pediatric metastatic RCC has a poor outlook. There are no published prospective studies demonstrating which adjuvant therapy could improve outcome. Sunitinib, a tyrosine kinase inhibitor, is recommended in this group despite limited evidence. This review provides an overview for pediatric RCC, including the evolving role of precision medicine.

Lymph node yield in pediatric, adolescent and young adult Renal Cell Carcinoma - How many are enough?

PURPOSE

Pediatric, adolescent and young adult (PAYA) patients with renal cell carcinoma (RCC) have a high rate of LN involvement, yet data to guide surgical lymph node (LN) management in this group is limited. The objective is to describe a LN yield threshold to quantify the chance of missing occult LN involvement at ≤10% in PAYAs with RCC.

MATERIALS & METHODS

The National Cancer Database was queried for patients aged ≤30 y with unilateral, non-metastaticRCC from 2004 to 2013. The probability of a false negative LN sampling was determined on the cohort of patients who had at least one positive LNand ≥ 2 LNs examined. For a given LN yield, the probability that a positive LN exists but none were found was estimated using a beta-binomial model.

RESULTS

We identified 112 patients meeting study criteria. Median age was 24 y and median tumor size was 9.5 cm (IQR 5.8-14). The median number of LNs sampled was 7 (IQR 4-12) and the median number of LNs positive was 4 (IQR 2-7). To achieve ≤10% probability of a false-negativeLN sampling, the beta-binomial model estimated that 5 LNs (95% CI4-7) must be sampled.

CONCLUSIONS

The desired LN yield to reduce the risk of a false-negativeLN sampling in PAYAs with RCC to ≤10% is 5. This is in keeping with prior studies identifying a LN yield of 6-10 to achieve the same. These data may be used to standardize surgical guidelines when treating PAYAs with renal tumors.

LEVEL OF EVIDENCE

II.

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.

Incidence, treatment, and outcomes of primary and recurrent Non-Wilms renal tumors in children: Report of 109 patients treated at a single institution

INTRODUCTION

Non-Wilms renal tumors represent a compelling subset of childhood renal tumors. However, their relative rarity renders accurate diagnosis, and therapy challenging which in some instance is inferred from their adult counterparts.

OBJECTIVE

To describe the incidence and analyze the diagnostic challenges, therapies and, outcomes of non-Wilms renal tumors at the largest tertiary cancer centre in India.

METHODS

All patients with histologically confirmed non-Wilms renal tumours diagnosed in the paediatric oncology unit of Tata Memorial Hospital between 2006 and 2019 were included. Data regarding clinical and radiological features and treatment outcomes were retrieved from the prospectively maintained institutional database. At the outset, histological types were categorised into a high and low-risk group depending on anticipated survival. Survival analysis was performed utilising the Kaplan-Meier method on SPSS software version 24.0.

RESULTS

Of the 569 patients with renal tumors, 109 (19%) patients with primary (n = 97) or recurrent (n = 12) non-Wilms renal tumors were included. Histological high-risk group included clear cell sarcoma (CCSK) (39.4%), renal cell carcinoma (RCC) (19.3%), malignant rhabdoid tumor (MRTK) (12.8%), Ewing's sarcoma (rES) (15.6%), synovial sarcoma (2%), and undifferentiated sarcoma (2%). The low-risk group comprised of congenital mesoblastic nephroma (CMN) (4.6%), cystic partially differentiated nephroblastoma (2%), and other rare tumors (3%). Diagnostic error occurred in 2 patients in the high-risk group. All low-risk tumours were treated with surgery alone and most (97%) high-risk tumors were operated either upfront (61.5%) or after preoperative chemotherapy (38.4%). Adjuvant therapy based on histology was offered to 70%. The recurrent tumors received various salvage treatments including chemotherapy; radiotherapy; surgery and immunotherapy, however, only 2 patients could be salvaged. The 3-year overall survival for the entire cohort with primary tumors was 59%, and the survival rates were 76.7%, 77.9%, 0.0%, and 52% for CCSK, RCC, MRTK, and rES (summary figure). Low-risk tumors had 100% survival while the recurrent tumors had a median survival of 10.5 months.

CONCLUSIONS

Non-Wilms renal tumors constitute a heterogeneous group of tumors, accounting for less than 20% of all renal tumors. Low-risk tumors are associated with excellent outcomes following surgery alone while the high-risk tumours have a variable outcome. MRTK and recurrent non-Wilms tumour have the worst survival. Favourable outcomes for CCSK and RCC and worst outcomes for MRTK were observed in this study. Renal ES have higher incidence of treatment failure and unsatisfactory outcomes. Recurrent non-Wilms tumours have an extremely poor outcome and more alternative or innovative approaches are needed for their treatment.

Treatment of advanced pediatric renal cell carcinoma

BACKGROUND

Pediatric renal cell carcinoma (pRCC) is the second most common renal malignancy of childhood; however, treatment data for advanced disease is lacking.

METHODS

A retrospective analysis of pRCC patients (age < 21 years at diagnosis) treated between 2000 and 2015 at Cincinnati Children's Hospital Medical Center was undertaken, with specific focus on medical therapies, accompanied by a detailed literature review.

RESULTS

Twenty-four patients (median age = 15 years) were identified; 11 were female. Past history of kidney pathology (4) and prior hematologic/oncologic diagnoses (5) were common associated findings. Translocation morphology RCC (tRCC) was the most common subtype (16; 64%), followed by papillary (6; 24%), clear cell renal cell carcinoma (ccRCC) (1), and chromophobe (1). The TNM stage distribution was I (8; 33%), II (2; 8%), III (3; 13%), and IV (11; 46%). Eleven patients with stage IV disease all had tRCC and received medicinal anticancer therapies, the most common being antiangiogenic (10), conventional chemotherapy (8), mTOR inhibition (7), and immunotherapy (3). Four patients also received small-port radiotherapy. The mean time to progression (TTP) was longest for axitinib (n = 2; TTP = 7.8 m; range 5.5-10 m) and sunitinib (n = 6; TTP = 4.7 m; range 0.3-12 m). Overall, 20 cases of pediatric RCC who received RCC-directed medicinal therapy with outcome data have been previously reported.

CONCLUSIONS

For patients with unresectable pRCC requiring systemic therapy, available data are scarce. Data herein support an increased TTP with antiangiogenic therapy in tRCC supporting a formal study of antiangiogenic therapies through multicooperative-group collaboration.

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.

Factors related to lymph node sampling at the time of surgery in children, adolescents, and young adults with unilateral non-metastatic renal cell carcinoma

INTRODUCTION

Renal cell carcinoma (RCC) is rare in the pediatric, adolescent, and young adult (PAYA) population. PAYA patients with RCC have a high rate of lymph node (LN) involvement, regardless of primary tumor size, yet data to guide surgical LN management in this group are limited.

OBJECTIVE

The objective of this study was to determine what factors are associated with LN sampling (protocol adherence) in PAYAs with RCC.

METHODS

The National Cancer Database (NCDB) between 2004 and 2013 was queried for patients aged ≤30 yrs with non-metastatic, unilateral RCC managed with surgery. Logistic regression analyses were performed to evaluate factors associated with LN sampling.

RESULTS

A total of 2857 patients met study criteria. Pathologically, 2510 (87.8%) patients were Nx, 278 (9.7%) N0, and 69 (2.4%) N1. Older age was associated with omission of LN sampling (odds ration [OR]: 1.065, 95% confidence interval [CI]: 1.04-1.1, P < 0.001). Higher institutional volume (OR: 0.971, 95% CI: 0.96-0.99, P < 0.001), stage 3 tumors (OR: 0.19, 95% CI: 0.11-0.33, P < 0.001), pre-operative clinical node involvement (OR: 0.32, 95% CI: 0.12-0.86, P = 0.024), tumor size >10 cm (OR: 0.27, 95% CI: 0.12-0.57, P = 0.001), and radical nephrectomy (OR: 0.245, 95% CI: 0.16-0.38, P < 0.001) were associated with patients undergoing LN sampling.

DISCUSSION

Lymph node sampling is performed in <15% of PAYA patients with RCC. Given the higher rate of translocation RCC pathology in younger patients, which leads to a higher prevalence of nodal involvement (especially with small masses), and the subsequent need for aggressive surgical control of disease, LN sampling and protocol adherence are potentially underutilized in this population and may present a unique opportunity for urologists to improve the care of PAYAs. Data from administrative databases are helpful for rare diseases such as PAYA RCC, but comes with limitations such as missing data. There are several factors that could contribute to LN sampling utilization (National comprehensive cancer network (NCCN) or Children's Oncology Group institution designation, surgeon experience, annual volume, specialty, operative approach, etc.) that cannot be further examined using the NCDB.

CONCLUSION

Pediatric, adolescent, and young adult patients with localized RCC are less likely to undergo surgical LN sampling if they are older, have tumors <10 cm or of less advanced stage, have no pre-operative clinical suspicion of LN involvement, are treated with partial nephrectomy, or are treated at lower volume centers. It appears that approaches from adults with RCC are being applied to PAYAs despite evidence that PAYAs with RCC experience a significant rate of LN involvement even with small tumors.

Reliability of intraoperative frozen section for the diagnosis of renal tumors suspicious for malignancy in children and adolescents

BACKGROUND

The ability of intraoperative frozen section (IFS) to reliably diagnose renal tumors in children and adolescents is largely unknown. The objective of our study is to evaluate the ability of IFS to establish a histologic diagnosis for renal tumors in this population.

METHODS

We reviewed our experience with patients who underwent IFS at the time of surgery for a renal tumor suspicious for malignancy from 2005 to 2015. The IFS was compared to the final pathology (FP). Data on concordance and reliability were analyzed.

RESULTS

One hundred thirty patients underwent surgical interventions for a renal tumor suspicious for malignancy, and 32 (25%) patients underwent IFS. Median turnaround time for IFS was 20 min (range 13-44). The histologic IFS diagnosis correlated with FP in 26 (81.2%) cases was discrepant in three (9.4%) cases, and IFS was deferred to FP in three (9.4%) cases (kappa 0.71, 95% confidence interval [CI]: 0.52-0.899, P < 0.001). The IFS correctly distinguished between Wilms tumor and non-Wilms tumor in 30 (94%) cases (kappa 0.874, 95% CI: 0.705-1, P < 0.001). A total of 17 of 19 (89.5%) Wilms tumors were correctly diagnosed by IFS, yielding a sensitivity of 0.89 (95% CI: 0.67-0.99) and a specificity of 1 (95% CI: 0.75-1).

CONCLUSION

IFS is a reliable tool to establish a histologic diagnosis and to differentiate between Wilms and non-Wilms tumors in children and adolescents with renal tumors. The use of IFS should be encouraged in cases in which obtaining a diagnosis will provide guidance for important "real-time" medical decision making, specifically additional adjunctive surgical procedures.

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.

Factors impacting survival in children with renal cell carcinoma

PURPOSE

Renal cell carcinoma (RCC) is an uncommon tumor in the pediatric population. We examined a large national cancer database to determine outcomes for children with RCC and to identify variables affecting long-term survival.

METHODS

The National Cancer Data Base (NCDB) was queried for patients age 0 to 17 years diagnosed with RCC from 1998-2011. Patient demographics, tumor stage and characteristics, management, and outcomes were evaluated.

RESULTS

A total of 304 children met inclusion criteria. Overall, 39% of children had stage I disease, 16% stage II, 33% stage III, and 12% stage IV. One-year and five-year survival for all children was 87% and 70%, respectively. Eighty-six percent of patients underwent surgical resection. In comparison to children who underwent complete nephrectomy, patients undergoing partial nephrectomy had smaller tumors and were of lower clinical stages. Survival following partial resection was 100% at one and five years. Age and gender had no significant impact on survival. Survival was negatively impacted by increasing tumor size (P<0.001), positive nodal status (P=0.001), and higher pathologic stage (P<0.001).

CONCLUSION

Children with renal cell carcinoma who undergo surgical resection have excellent one-year and five-year survival. Overall survival is significantly affected by pathologic stage, tumor size, and nodal status.

Characterization of adolescent and pediatric renal cell carcinoma: A report from the Children's Oncology Group study AREN03B2

BACKGROUND

The current study was conducted to characterize the epidemiology, histology, and radiographic features of as well as the surgical approach to pediatric and adolescent renal cell carcinoma (pRCC).

METHODS

pRCC cases prospectively enrolled on the Children's Oncology Group study AREN03B2 underwent central pathology, radiology, surgery, and oncology review.

RESULTS

As of June 2012, 120 of a total of 3250 patients enrolled on AREN03B2 (3.7%) were found to have unilateral RCC (median age, 12.9 years [range, 1.9-22.1 years]; 52.5% were female). Central review classified these as translocation morphology (56 patients), papillary (20 patients), renal medullary carcinoma (13 patients), chromophobe (4 patients), oncocytoma (1 patient), conventional clear cell (1 patient), and RCC not otherwise specified (25 patients). Lymph node (LN) involvement (N+) was found in 35 of 73 cases (47.9%) for which LNs were sampled, including 19 of 40 cases with primary tumors measuring <7 cm (47.5%). Using a size cutoff of 1 cm, imaging detection of LN involvement had a sensitivity of 57.14% (20 of 35 cases; 95% CI, 39.35%-73.68%) and a specificity of 94.59% (35 of 37 cases; 95% CI, 81.81%-99.34%). Distant metastases were present in 23 cases (19.2%). Initial surgery was radical nephrectomy in 88 patients (73.3%), nephron-sparing surgery in 18 patients (15.0%), and biopsy in 14 patients (11.7%). Compared with patients undergoing radical nephrectomy, those treated with nephron-sparing surgery were less likely to have LNs sampled (6 of 18 patients [33.3%] vs 65 of 88 patients [73.9%]; P = .002).

CONCLUSIONS

Translocation RCC is the most common form of pediatric and adolescent RCC. Lymph node disease is common and observed among patients with small primary tumors. Imaging has a high specificity but relatively low sensitivity for the detection of such lymph node disease. Failure to sample LNs results in incomplete staging and potentially inadequate disease control for younger patients with RCC.

Metastatic renal cell carcinoma in children and adolescents: a 30-year unsuccessful story

BACKGROUND

Because of the rare occurrence of renal cell carcinoma (RCC) among children very little is known about this malignancy in pediatric age. We aimed adding knowledge on the clinical characteristics and outcome of metastatic (m) RCC in children and adolescents.

PATIENTS AND METHODS

The series included 14 stage 4 RCC patients with a median age at diagnosis of 155.5 months, observed at the Italian Pediatric Hematology and Oncology Association (AIEOP) centers from January 1973 to November 2010. We were able to reevaluate histopatology of 11 out of the 14 patients and perform immunostaining for TFE3 in 9 out of the 11 patients.

RESULTS

Of the 14 patients under study, 5 (3 girls) had a translocation morphology TFE+ RCC, 2 were reassigned as papillary type 1 or 2, respectively, 2 tumor specimens with primary clear cell histology had confirmed the initial histologic diagnosis, and 2-whose biopsy specimen was insufficient-had the diagnosis of RCC not further specified with subtyping. In the remaining 3 cases, the initial diagnosis of clear cell carcinoma was left. Overall, 6 patients received chemotherapy, 9 immunotherapy, and 2 adjuvant antiangiogenic therapy. Overall, 11 patients (78.5%) never achieved complete remission and died from progressive disease 1 to 16 months after diagnosis (median overall survival 5.5 mo). Three patients, 2 of whom received adjuvant antiangiogenic therapy, relapsed to lung at 3, 6, and 8 months after diagnosis, and died 18, 32, and 33 months after diagnosis, respectively.

CONCLUSIONS

Despite their possibly different biology, childhood and adult mRCC seems to be sharing comparable outcomes. Because of the very low incidence of mRCC (about 20%) in children and adolescents, an international pediatric cooperation to address biological studies and assess the novel targeted approaches is needed.

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.

Bilateral renal cell carcinoma in a child

Renal cell carcinoma is a rare renal tumor in the pediatric population with an incidence of 0.1-0.3%. We report on the first case of bilateral renal clear cell carcinoma that was treated by partial nephrectomies. We performed a complete genetic evaluation to exclude a family inheritance and we looked at the deletions associated with the possible histologic subtypes of renal cell carcinoma. The patient had no evidence of recurrence after 80-month follow-up and her renal function remained normal.

[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.

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.

Pediatric renal cell carcinoma

Renal cell carcinoma (RCC) comprises about 5% of pediatric renal neoplasms. It has been recognized as a second malignancy in multiple reports. It is generally symptomatic at diagnosis, and most children with RCC present with more locally advanced disease than do adults. Contemporary investigation of pediatric RCC has demonstrated that a large percentage of these tumors bear cytogenetic translocations involving the MiT family of transcription factors. Surgical therapy for these children resembles operative intervention for adult RCC, though debate continues about the precise role of lymph node dissection. There are no adequately powered studies to support conclusions about adjuvant or neoadjuvant chemotherapy for children with RCC. This may be ameliorated by a multi-institutional protocol which is enrolling patients.