Renal Cell Carcinoma in Children and Young Adults: Clinicopathological, Immunohistochemical, and VHL Gene Analysis of 46 Cases With Follow-up

Comprehensive molecular characterization of TFE3-rearranged renal cell carcinoma

TFE3-rearranged renal cell cancer (tRCC) is a rare form of RCC that involves chromosomal translocation of the Xp11.2 TFE3 gene. Despite its early onset and poor prognosis, the molecular mechanisms of the pathogenesis of tRCC remain elusive. This study aimed to identify novel therapeutic targets for patients with primary and recurrent tRCC. We collected 19 TFE3-positive RCC tissues that were diagnosed by immunohistochemistry and subjected them to genetic characterization to examine their genomic and transcriptomic features. Tumor-specific signatures were extracted using whole exome sequencing (WES) and RNA sequencing (RNA-seq) data, and the functional consequences were analyzed in a cell line with TFE3 translocation. Both a low burden of somatic single nucleotide variants (SNVs) and a positive correlation between the number of somatic variants and age of onset were observed. Transcriptome analysis revealed that four samples (21.1%) lacked the expected fusion event and clustered with the genomic profiles of clear cell RCC (ccRCC) tissues. The fusion event also demonstrated an enrichment of upregulated genes associated with mitochondrial respiration compared with ccRCC expression profiles. Comparison of the RNA expression profile with the TFE3 ChIP-seq pattern data indicated that PPARGC1A is a metabolic regulator of the oncogenic process. Cell proliferation was reduced when PPARGC1A and its related metabolic pathways were repressed by its inhibitor SR-18292. In conclusion, we demonstrate that PPARGC1A-mediated mitochondrial respiration can be considered a potential therapeutic target in tRCC. This study identifies an uncharacterized genetic profile of an RCC subtype with unique clinical features and provides therapeutic options specific to tRCC.

Clinicopathologic Classification of Renal Cell Carcinoma in Patients ≤40 Years Old From Peru

INTRODUCTION

There are scant data on renal cell carcinoma (RCC) from relatively younger patients in South America using contemporary classification.

METHODS

Fifty-nine consecutively treated patients with RCC (≤40 years old) were assessed from the National Institute of Neoplastic Diseases in Peru from 2008 to 2020 (34 males; 25 females), age range of 13 to 40 years.

RESULTS

Most common presenting symptoms were flank pain (n = 40), hematuria (n = 19), and weight loss (n = 12). Associated conditions included 4 patients with proven or presumed tuberous sclerosis and 1 patient with von Hippel Lindau syndrome, all with clear cell RCC. Tumor histopathology was clear cell RCC in 32 of 59 (54%), chromophobe RCC in 6 of 59 (10%), and 5 of 59 (8%) each of papillary RCC and MiT family translocation-associated RCC. Four of 59 (7%) were FH-deficient RCC and 2 of 59 (3%) remained unclassified. The remaining tumors were isolated examples of clear cell papillary renal cell tumor, eosinophilic solid and cystic RCC (ESC RCC), RCC with fibromyomatous stroma, sarcomatoid RCC, and sarcomatoid clear cell RCC. Of the 4 FH-deficient RCCs, none had the classic morphology. The 5 MiT family translocation RCCs had variable morphology. There were 41 tumors without recurrence or metastases, 3 tumors with local recurrence only, 8 tumors with metastases only, and 7 tumors with both local recurrence and metastases.

CONCLUSIONS

The current study demonstrates the importance of special studies in accurately classifying RCC in younger individuals. The distribution of RCC subtypes in younger individuals is similar between 2 representative large institutions of the United States and Peru.

Pediatric renal tumor epidemiology: Global perspectives, progress, and challenges

Pediatric renal tumors account for 3%-11% of childhood cancers, the most common of which is Wilms tumor or nephroblastoma. Epidemiology plays a key role in cancer prevention and control by describing the distribution of cancer and discovering risk factors for cancer. Large pediatric research consortium trials have led to a clearer understanding of pediatric renal tumors, identification of risk factors, and development of more risk-adapted therapies. These therapies have improved event-free and overall survival for children. However, several challenges remain and not all children have benefited from the improved outcomes. In this article, we review the global epidemiology of pediatric renal tumors, including key consortium and global studies. We identify current knowledge gaps and challenges facing both high and low middle-incomes countries.

Nephron-sparing surgery for renal cell carcinoma in children and young adults: A systematic review

OBJECTIVE

To determine the patient characteristics and role of nephron-sparing surgery (NSS) in the treatment of children and young adults with renal cell carcinoma (RCC).

METHODS

A systematic search of Embase, MEDLINE, and Scopus databases was conducted in December 2021 according to Cochrane collaboration recommendations. All included manuscripts were assessed for patient characteristics and all reported outcomes for patients undergoing partial nephrectomy (PN), and radical nephrectomy (RN) outcomes were abstracted as a comparison group. Primary outcomes included surgical outcomes, overall survival, kidney outcomes. Outcomes were pooled with weighted mean and ranges. Meta-analysis was not performed given study quality. This systematic review was prospectively registered on PROSPERO (CRD42022300261).

RESULTS

We found a total of 16 studies describing 119 and 559 unique patients undergoing PN and RN, respectively, with a mean age of 12.2 years and mean follow-up of 59.1 months. The mean tumor size for patients undergoing PN was 3.5 cm. Of the 113 patients undergoing PN with available data, 109 were alive at follow-up (98%). No studies reported long-term kidney outcomes, and four studies reported surgical outcomes. All studies had at least moderate risk of bias.

CONCLUSIONS

The use of NSS in children and young adults with RCC is feasible in selected patients. However, small sample sizes, confounding, and low study quality limit clinical recommendation on NSS in this population. There are significant opportunities for future research on the use of NSS in RCC, especially with systematic reporting of oncological, kidney, and surgical outcomes.

Pediatric renal tumor epidemiology: Global perspectives, progress, and challenges

Pediatric renal tumors account for 3%-11% of childhood cancers, the most common of which is Wilms tumor or nephroblastoma. Epidemiology plays a key role in cancer prevention and control by describing the distribution of cancer and discovering risk factors for cancer. Large pediatric research consortium trials have led to a clearer understanding of pediatric renal tumors, identification of risk factors, and development of more risk-adapted therapies. These therapies have improved event-free and overall survival for children. However, several challenges remain and not all children have benefited from the improved outcomes. In this article, we review the global epidemiology of pediatric renal tumors, including key consortium and global studies. We identify current knowledge gaps and challenges facing both high and low middle-incomes countries.

"Papillary Adenoma-like" Renal Tumor with TFE3 Gene Rearrangement, A Potential Precursor to or Early Event in the Development of TFE3 Translocation Renal Cell Carcinoma

MiT family translocation renal cell carcinomas harbor gene fusion involving members of MiT family of transcription factors. Their precursor lesions have not been identified. Herein, we report the first case of small papillary tumors morphologically resembling papillary adenomas but harboring TFE3 gene alteration. The patient was a 23-year old man with multiple small papillary tumors in the right kidney discovered following a gunshot wound injury. These lesions were < 5 mm, well-circumscribed but not encapsulated tubulopapillary proliferation lined with a single layer of cuboidal cells with WHO/ISUP grade 1 or 2 nuclei. The tumor cells were immunoreactive to PAX8, AMACR, high molecular weight cytokeratin, and keratin 7 and negative for CD10, CA9, TTF1, and cathepsin K. Morphologically and immunohistochemically, these lesions were diagnosed as papillary adenomas. TFE3 gene rearrangement was confirmed by fluorescence in-situ hybridization (FISH) using a TFE3 break-apart probe. We term these tumors "papillary adenoma-like" renal tumor with TFE3 gene rearrangement. These tumors are likely a precursor to or represent an early event in the development of TFE3 translocation renal cell carcinomas. An understanding of such tumors to translocation renal cell carcinoma progression can provide insight into the pathogenic mechanism, and ultimately aid the diagnosis and management of translocation renal cell carcinoma.

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.

Key Renal Neoplasms With a Female Predominance

Renal neoplasms largely favor male patients; however, there is a growing list of tumors that are more frequently diagnosed in females. These tumors include metanephric adenoma, mixed epithelial and stromal tumor, juxtaglomerular cell tumor, mucinous tubular and spindle cell carcinoma, Xp11.2 (TFE3) translocation-associated renal cell carcinoma, and tuberous sclerosis complex (somatic or germline) associated renal neoplasms. The latter category is a heterogenous group with entities still being delineated. Eosinophilic solid and cystic renal cell carcinoma is the best-described entity, whereas, eosinophilic vacuolated tumor is a proposed entity, and the remaining tumors are currently grouped together under the umbrella of tuberous sclerosis complex/mammalian target of rapamycin-related renal neoplasms. The entities described in this review are often diagnostic considerations when evaluating renal mass tissue on biopsy or resection. For example, Xp11.2 translocation renal cell carcinoma is in the differential when a tumor has clear cell cytology and papillary architecture and occurs in a young or middle-aged patient. In contrast, tuberous sclerosis complex-related neoplasms often enter the differential for tumors with eosinophilic cytology. This review provides an overview of the clinical, gross, microscopic, immunohistochemical, genetic, and molecular alterations in key renal neoplasms occurring more commonly in females; differential diagnoses are also discussed regardless of sex predilection.

Renal Cancer Without Primary Cancer in the Kidney: Extra-Renal TFE3 Translocation Associated Renal Cell Carcinoma

We report a case of an isolated para-aortic retroperitoneal renal cell carcinoma (RCC) in the absence of a primary cancer in the kidney. Single case reports in the literature have described extra-renal RCC in different locations with no evidence of primary renal tumor. We present the initial presentation, diagnostic imaging, surgical treatment, and pathologic evaluation. Immunohistochemistry demonstrated positivity for TFE3 and TFEB, both of which are Microphthalmia associated transcription factors (MiT) associated with translocation RCCs. We hypothesize these few cases of extra-renal RCC represent rare forms of translocation RCC.

Characteristics and outcome of pediatric renal cell carcinoma patients registered in the International Society of Pediatric Oncology (SIOP) 93-01, 2001 and UK-IMPORT database: A report of the SIOP-Renal Tumor Study Group

In children, renal cell carcinoma (RCC) is rare. This study is the first report of pediatric patients with RCC registered by the International Society of Pediatric Oncology-Renal Tumor Study Group (SIOP-RTSG). Pediatric patients with histologically confirmed RCC, registered in SIOP 93-01, 2001 and UK-IMPORT databases, were included. Event-free survival (EFS) and overall survival (OS) were analyzed using the Kaplan-Meier method. Between 1993 and 2019, 122 pediatric patients with RCC were registered. Available detailed data (n = 111) revealed 56 localized, 30 regionally advanced, 25 metastatic and no bilateral cases. Histological classification according to World Health Organization 2004, including immunohistochemical and molecular testing for transcription factor E3 (TFE3) and/or EB (TFEB) translocation, was available for 65/122 patients. In this group, the most common histological subtypes were translocation type RCC (MiT-RCC) (36/64, 56.3%), papillary type (19/64, 29.7%) and clear cell type (4/64, 6.3%). One histological subtype was not reported. In the remaining 57 patients, translocation testing could not be performed, or TFE-cytogenetics and/or immunohistochemistry results were missing. In this group, the most common RCC histological subtypes were papillary type (21/47, 44.7%) and clear cell type (11/47, 23.4%). Ten histological subtypes were not reported. Estimated 5-year (5y) EFS and 5y OS of the total group was 70.5% (95% CI = 61.7%-80.6%) and 84.5% (95% CI = 77.5%-92.2%), respectively. Estimated 5y OS for localized, regionally advanced, and metastatic disease was 96.8%, 92.3%, and 45.6%, respectively. In conclusion, the registered pediatric patients with RCC showed a reasonable outcome. Survival was substantially lower for patients with metastatic disease. This descriptive study stresses the importance of full, prospective registration including TFE-testing.

Factors Associated with Survival From Xp11.2 Translocation Renal Cell Carcinoma Diagnosis-A Systematic Review and Pooled Analysis

Purpose: Xp11.2 translocation renal cell carcinoma (Xp11.2 tRCC) is a rare subtype of renal cell carcinoma (RCC), characterized by translocations of Xp11.2 breakpoints, involving of the transcription factor three gene (TFE3). The aim of our study was to comprehensively characterize the clinical characteristics and outcomes, and to identify risk factors associated with OS and PFS in Xp11.2 tRCC patients.

Methods: Literature search on Xp11.2 tRCC was performed using databases such as pubmed EMBASE and Web of Science. Studies were eligible if outcomes data (OS and/or PFS) were reported for patients with a histopathologically confirmed Xp11.2 tRCC. PFS and OS were evaluated using the univariable and multivariable Cox regression model.

Results: There were 80 eligible publications, contributing 415 patients. In multivariable analyses, the T stage at presentation was significantly associated with PFS (HR: 3.87; 95% CI: 1.70 to 8.84; p = 0.001). The median time of PFS was 72 months. In the multivariable analyses, age at diagnosis (HR: 2.16; 95% CI: 1.03 to 4.50; p = 0.041), T stage at presentation (HR: 4.44; 95% CI: 2.16 to 9.09; p < 0.001) and metastasis status at presentation (HR: 2.67; 95% CI: 1.12 to 6.41; p = 0.027) were all associated with OS, with a median follow-up time of 198 months.

Conclusion: T stage at presentation is the only factor that is associated with both PFS and OS in patients with Xp11.2 tRCC. Also, patients over 45 or with metastases are more likely to have poorer OS.

Pediatric Renal Tumors: Updates in the Molecular Era

Molecular characterization has led to advances in the understanding of pediatric renal tumors, including the association of pediatric cystic nephromas with DICER1 tumor syndrome, the metanephric family of tumors with somatic BRAF mutations, the characterization of ETV6-NTRK3-negative congenital mesoblastic nephromas, the expanded spectrum of gene fusions in translocation renal cell carcinoma, the relationship of clear cell sarcoma of the kidney with other BCOR-altered tumors, and the pathways affected by SMARCB1 alterations in rhabdoid tumors of the kidney. These advances have implications for diagnosis, classification, and treatment of pediatric renal tumors.

Tumor Lipids of Pediatric Papillary Renal Cell Carcinoma Stimulate Unconventional T Cells

Papillary renal cell carcinoma (PRCC) is a rare entity in children with no established therapy protocols for advanced diseases. Immunotherapy is emerging as an important therapeutic tool for childhood cancer. Tumor cells can be recognized and killed by conventional and unconventional T cells. Unconventional T cells are able to recognize lipid antigens presented via CD1 molecules independently from major histocompatibility complex, which offers new alternatives for cancer immunotherapies. The nature of those lipids is largely unknown and α-galactosylceramide is currently used as a synthetic model antigen. In this work, we analyzed infiltrating lymphocytes of two pediatric PRCCs using flow cytometry, immunohistochemistry and qRT-PCR. Moreover, we analyzed the CD1d expression within both tumors. Tumor lipids of PRCC samples and three normal kidney samples were fractionated and the recognition of tumor own lipid fractions by unconventional T cells was analyzed in an in vitro assay. We identified infiltrating lymphocytes including γδ T cells and iNKT cells, as well as CD1d expression in both samples. One lipid fraction, containing ceramides and monoacylglycerides amongst others, was able to induce the proliferation of iNKT cells isolated from peripheral blood mononuclear cells (PBMCs) of healthy donors and of one matched PRCC patient. Furthermore, CD1d tetramer stainings revealed that a subset of iNKT cells is able to bind lipids being present in fraction 2 via CD1d. We conclude that PRCCs are infiltrated by conventional and unconventional T cells and express CD1d. Moreover, certain lipids, present in pediatric PRCC, are able to stimulate unconventional T cells. Manipulating these lipids and T cells may open new strategies for therapy of pediatric PRCCs.

Characteristics and Outcome of Children with Renal Cell Carcinoma: A Narrative Review

Pediatric renal cell carcinoma (RCC) is a rare type of kidney cancer, most commonly occurring in teenagers and young adolescents. Few relatively large series of pediatric RCC have been reported. Knowledge of clinical characteristics, outcome and treatment strategies are often based on the more frequently occurring adult types of RCC. However, published pediatric data suggest that clinical, molecular and histological characteristics of pediatric RCC differ from adult RCC. This paper summarizes reported series consisting of ≥10 RCC pediatric patients in order to create an up-to-date overview of the clinical and histopathological characteristics, treatment and outcome of pediatric RCC patients.

Contrast-enhanced ultrasound findings of adult renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion: comparison with clear cell renal cell carcinoma and papillary renal cell carcinoma

BACKGROUND

To investigate the contrast-enhanced ultrasound (CEUS) findings of renal cell carcinoma (RCC) associated with Xp11.2 translocation/TFE3 gene fusion (Xp11.2/TFE3) in adult patients by comparison with those of clear cell RCC (ccRCC) and papillary RCC (pRCC).

METHODS

In total, 110 patients (110 renal masses) who underwent CEUS examinations were enrolled in this study. The cases included 18 Xp11.2/TFE3 RCCs, 60 ccRCCs and 32 pRCCs. All masses were confirmed by operative pathology. The CEUS imaging data of these patients were retrospectively analysed by two readers. The conventional US and CEUS features of Xp11.2/TFE3 RCC were compared with those of ccRCC and pRCC.

RESULTS

The age of the patients with Xp11.2/TFE3 RCC ranged from 20 to 68 years, with a mean age of 38.3 ± 16.3 years and a slight female predominance. The weighted kappa value that interprets the concordance between the interobserver agreement of the US and CEUS features ranged from 0.61 to 0.89. On conventional US and CEUS imaging of Xp11.2/TFE3 RCCs, the tumours were hypoechoic (6/18, 33.3%), isoechoic (8/18, 44.4%), and hyperechoic (4/18, 22.2%). The cystic component was present in 5 cases (27.8%), calcification was present in 9 cases (50.0%), and colour flow signal was present in 7 cases (38.9%). Most cases showed simultaneous wash-in (11/18, 61.1%); the peak enhancement showed hypoenhancement (6/18, 33.3%), isoenhancement (10/18, 55.6%), and hyperenhancement (2/18, 11.1%); most cases exhibited heterogeneous enhancement (12/18, 66.7%) and fast- or simultaneous-out (16/18, 88.9%); and a pseudocapsule was present in 6 cases (33.3%). In the multivariate logistic regression analysis, calcification and lower peak enhancement were more likely to be present in Xp11.2/TFE3 RCC than in ccRCC (P < 0.05), and younger age and relatively high peak enhancement were more likely to be present in Xp11.2/TFE3 RCC than in pRCC (P < 0.05). The calcification combined peak enhancement model differentiated Xp11.2/TFE3 RCC from ccRCC, and the age combined peak enhancement model differentiated Xp11.2/TFE3 RCC from pRCC with an AUC, a sensitivity and a specificity of 0.896, 94.4% and 73.3% and 0.786, 50.0% and 100.0%, respectively.

CONCLUSIONS

The specific CEUS features combined with demographic information and clinical symptoms may be helpful for differentiating Xp11.2/TFE3 RCC from ccRCC and pRCC.

Prognostic factors for the survival of patients with papillary renal cell carcinoma after surgical management

PURPOSE

To examine the possible prognostic factors in patients with type 1 and type 2 papillary renal cell carcinoma (pRCC) after surgical management and to identify the independent predictive factors of the prognosis.

METHODS

From 2010 to 2017, 1405 patients underwent surgery for renal cell carcinoma, of whom 114 had type 1 or type 2 pRCC and follow-up data were available for 88 patients. Clinicopathological and prognostic parameters were compared between type 1 and type 2 pRCC. Possible prognostic factors were retrospectively analyzed by univariate and multivariate analyses with Cox regression.

RESULTS

The study included 63 males and 25 females with a mean age of 54.27 ± 12.91. 53 patients were diagnosed by regular physical examination and others presented with hematuria or lumbago. 53 (60.2%) underwent radical nephrectomy and 35 (39.8%) underwent nephron sparing surgery. After a mean follow-up of 46.08 ± 22.65 months, 16 patients died of pRCC metastasis and the 5-year disease-specific survival was 79.3%. The comparison of the 39 (44.3%) type 1 and 49 (55.7%) type 2 pRCCs revealed that type 2 pRCC had significantly higher grade and worse prognosis. Univariate analysis showed that symptomatic diagnosis, type, grade, and tumor stage were prognostic factors. Multivariate analysis identified that type and tumor stage were independent factors of the prognosis.

CONCLUSIONS

Pathological type and tumor stage could serve as independent factors for the prognosis of patients with pRCC.

Incidence and significance of psammoma bodies in Xp11.2 translocation renal cell carcinoma and papillary renal cell carcinoma

The aim of the present study was to investigate the incidence and significance of psammoma bodies (PBs) in Xp11.2 translocation renal cell carcinoma (Xp11.2 tRCC) and papillary renal cell carcinoma (PRCC). The presence of PBs, irregular calcifications, hyaline globules and nested architecture in RCC tissues, which included 47 cases of Xp11.2 tRCC and 95 cases of PRCC, was examined by two pathologists. Compared with PRCC, patients with Xp11.2 tRCC exhibited a higher frequency of PBs, hyaline globules and nested architecture. The presence of PBs in combination with the occurrence of a nested architecture achieved a specificity of 93.7% when diagnosing Xp11.2 tRCC. However, there were no significant differences in the overall survival between patients with and without PBs in both types of RCC. Therefore, the presence of PBs combined with nested architecture may provide guidance for the diagnosis of Xp11.2 tRCC; however, PBs cannot predict tumor behavior in Xp11.2 tRCC or PRCC.

Does the Fuhrman or World Health Organization/International Society of Urological Pathology Grading System Apply to the Xp11.2 Translocation Renal Cell Carcinoma?: A 10-Year Single-Center Study

The Fuhrman and World Health Organization/International Society of Urological Pathology (WHO/ISUP) grading systems are widely used to predict survival for patients with conventional renal cell carcinoma. To determine the validity of nuclear grading systems (both the Fuhrman and the WHO/ISUP) and the individual components of the Fuhrman grading system in predicting the prognosis of Xp11.2 translocation renal cell carcinoma (Xp11.2 tRCC), we identified and followed up 47 patients with Xp11.2 tRCC in our center from January 2007 to June 2017. The Fuhrman and WHO/ISUP grading was reassigned by two pathologists. Nuclear size and shape were determined for each case based on the greatest degree of nuclear pleomorphism using image analysis software. Univariate and multivariate analyses were performed to evaluate the capacity of the grading systems and nuclear parameters to predict overall survival and progression-free survival. On univariate Cox regression analysis, the parameters of nuclear size were associated significantly with overall survival and progression-free survival, whereas the grading systems and the parameters of nuclear shape failed to reach a significant correlation. On multivariate analysis, however, none of the parameters was associated independently with survival. Our findings indicate that neither the Fuhrman nor the WHO/ISUP grading system is applicable to Xp11.2 tRCC. The assessment of nuclear size instead may be novel outcome predictors for patients with Xp11.2 tRCC.

The classification of pediatric and young adult renal cell carcinomas registered on the children's oncology group (COG) protocol AREN03B2 after focused genetic testing

BACKGROUND

Renal cell carcinomas (RCCs) are rare in young patients. Knowledge of their pathologic and molecular spectrum remains limited, and no prospective studies have been performed to date in this population. This study analyzes patients diagnosed with RCC who were prospectively enrolled in the AREN03B2 Children's Oncology Group (COG). The objective was to classify these tumors with the aid of focused genetic testing and to characterize their features.

METHODS

All tumors registered as RCC by central review were retrospectively re-reviewed and underwent additional ancillary studies. Tumors were classified according to the 2016 World Health Organization classification system when possible.

RESULTS

In total, 212 tumors were identified, and these were classified as microphthalmia transcription factor (MiT) translocation RCC (MiT-RCC) (41.5%), papillary RCC (16.5%), renal medullary carcinoma (12.3%), chromophobe RCC (6.6%), clear cell RCC (3.3%), fumarate hydratase-deficient RCC (1.4%), and succinate dehydrogenase-deficient RCC (0.5%). Other subtypes included tuberous sclerosis-associated RCC (4.2%), anaplastic lymphoma kinase (ALK)-rearranged RCC (3.8%), thyroid-like RCC (1.4%), myoepithelial carcinoma (0.9%), and unclassified (7.5%). MiT-RCCs were classified as either transcription factor E3 (TFE3) (93.2%) or EB (TFEB) (6.8%) translocations, and characterization of fusion partners was possible in most tumors.

CONCLUSIONS

The current study delineates the frequency of distinct RCC subtypes in a large prospective series of young patients and contributes knowledge to the diagnostic, clinical, and genetic features of MiT-RCC, the most common subtype among this age group. The identification of rare subtypes expands the spectrum of RCC in young patients, supporting the need for a thorough diagnostic workup. These studies may aid in the introduction of specific therapies for different RCC subtypes in the future. Cancer 2018. © 2018 American Cancer Society.

Ultrasonographic Findings of Renal Cell Carcinomas Associated with Xp11.2 Translocation/TFE3 Gene Fusion

Objective

This study was to investigate the features of renal carcinomas associated with Xp11.2 translocations/TFE3 gene fusions (Xp11.2-RCC) on conventional ultrasound (US) and contrast-enhanced ultrasound (CEUS).

Methods

US and CEUS features of twenty-two cases with histopathologically proven Xp11.2-RCC were retrospectively reviewed.

Results

22 patients (11 males, 11 females) were included in this study, with a mean age of 28.3 ± 20.4 years. Eight tumors (36.3%, 8/22) were in left kidney, and 14 tumors (63.7%, 14/22) were in right kidney. All tumors (100%, 22/22) were mixed echogenicity type. 13 tumors (59.1%, 13/22) presented small dotted calcifications. The boundary of 14 tumors (63.6%, 14/22) was sharp and the other 8 tumors' (36.4%, 8/22) boundary was blurry. By CEUS, in early phase, the solid element of all tumors showed obvious enhancement. In delayed phase, 13 tumors showed hypoenhancement, seven tumors showed isoenhancement, and 2 tumors showed hyperenhancement. There were irregular nonenhancement areas in all tumors inside.

Conclusions

By US and CEUS, when children and adolescents were found to have hyperechoic mixed tumor in kidney with sharp margin and calcification, and the tumors showed obvious enhancement and hypoenhancement with irregular nonenhancement areas in the tumor in early phase and delayed phase, respectively, Xp11.2-RCC should be suspected.

Xp11.2 translocation renal cell carcinoma with TFE3 gene fusion: A case report

Xp11.2 translocation renal cell carcinoma (RCC) with transcription factor E3 (TFE3) gene fusion is a rare tumor, and the prognosis of this tumor is poorer compared with that of other subtypes of RCC. The patient presented herein was a 70-year-old man who presented with a solid mass sized ~8.2×6.1 cm in the right kidney and underwent radical right nephrectomy. Following pathological and immunohistochemical (IHC) examination and fluorescent in situ hybridization (FISH), the patient was diagnosed with Xp11.2 translocation RCC with TFE3 gene fusion. These tumors are more commonly encountered in children rather than in adults, and adult Xp11.2 translocation RCC is associated with a poorer prognosis compared with its pediatric counterpart. IHC assay and FISH are important diagnostic methods. However, there is currently no established effective treatment for Xp11.2 RCC.

PRCC-TFE3 dual-fusion FISH assay: A new method for identifying PRCC-TFE3 renal cell carcinoma in paraffin-embedded tissue

PRCC-TFE3 renal cell carcinoma (RCC) is one of the most common types of Xp11.2 translocation renal cell carcinoma (tRCC), of which the diagnosis mainly relies on reverse transcription-polymerase chain reaction (RT-PCR) or chromosomal analysis in fresh frozen samples. Herein, we developed a new dual-fusion fluorescence in situ hybridization (FISH) probe to succinctly identify PRCC-TFE3 RCC in paraffin-embedded tissue. We immunohistochemically analyzed TFE3 and cathepsin K expression in 23 cases of Xp11.2 tRCC which had been confirmed by break-apart TFE3 FISH probe. Next, the dual-fusion FISH assay was performed on these selected cases. Twenty typical cases of clear renal cell carcinoma and 20 cases of papillary renal cell carcinoma were collected as control groups. Seven cases were finally confirmed as PRCC-TFE3 RCC by FISH detection, emerging dual-fusion signals, of which 2 cases were identified as PRCC-TFE3 RCC by RT-PCR previously. All remaining cases were negative for the PRCC-TFE3 rearrangement by FISH. The TFE3 immunohistochemistry was positive in 22/23 cases and the cathepsin K was positive in 16/23 cases. All 7 PRCC-TFE3 RCCs showed positive cathepsin K immunoreactivity. Our results reveal that PRCC-TFE3 dual-fusion FISH probe is an efficient and concise technique for diagnosing PRCC-TFE3 RCC in paraffin-embedded tissue.

Implementation of next generation sequencing into pediatric hematology-oncology practice: moving beyond actionable alterations

BACKGROUND

Molecular characterization has the potential to advance the management of pediatric cancer and high-risk hematologic disease. The clinical integration of genome sequencing into standard clinical practice has been limited and the potential utility of genome sequencing to identify clinically impactful information beyond targetable alterations has been underestimated.

METHODS

The Precision in Pediatric Sequencing (PIPseq) Program at Columbia University Medical Center instituted prospective clinical next generation sequencing (NGS) for pediatric cancer and hematologic disorders at risk for treatment failure. We performed cancer whole exome sequencing (WES) of patient-matched tumor-normal samples and RNA sequencing (RNA-seq) of tumor to identify sequence variants, fusion transcripts, relative gene expression, and copy number variation (CNV). A directed cancer gene panel assay was used when sample adequacy was a concern. Constitutional WES of patients and parents was performed when a constitutionally encoded disease was suspected. Results were initially reviewed by a molecular pathologist and subsequently by a multi-disciplinary molecular tumor board. Clinical reports were issued to the ordering physician and posted to the patient's electronic medical record.

RESULTS

NGS was performed on tumor and/or normal tissue from 101 high-risk pediatric patients. Potentially actionable alterations were identified in 38% of patients, of which only 16% subsequently received matched therapy. In an additional 38% of patients, the genomic data provided clinically relevant information of diagnostic, prognostic, or pharmacogenomic significance. RNA-seq was clinically impactful in 37/65 patients (57%) providing diagnostic and/or prognostic information for 17 patients (26%) and identified therapeutic targets in 15 patients (23%). Known or likely pathogenic germline alterations were discovered in 18/90 patients (20%) with 14% having germline alternations in cancer predisposition genes. American College of Medical Genetics (ACMG) secondary findings were identified in six patients.

CONCLUSIONS

Our results demonstrate the feasibility of incorporating clinical NGS into pediatric hematology-oncology practice. Beyond the identification of actionable alterations, the ability to avoid ineffective/inappropriate therapies, make a definitive diagnosis, and identify pharmacogenomic modifiers is clinically impactful. Taking a more inclusive view of potential clinical utility, 66% of cases tested through our program had clinically impactful findings and samples interrogated with both WES and RNA-seq resulted in data that impacted clinical decisions in 75% of cases.

Molecular genetics and immunohistochemistry characterization of uncommon and recently described renal cell carcinomas

Renal cell carcinoma (RCC) compromises multiple types and has been emerging dramatically over the recent several decades. Advances and consensus have been achieved targeting common RCCs, such as clear cell carcinoma, papillary RCC and chromophobe RCC. Nevertheless, little is known on the characteristics of several newly-identified RCCs, including clear cell (tubulo) papillary RCC, Xp11 translocation RCC, t(6;11) RCC, succinate dehydrogenase (SDH)-deficient RCC, acquired cystic disease-associated RCC, hereditary leiomyomatosis RCC syndrome-associated RCC, ALK translocation RCC, thyroid-like follicular RCC, tubulocystic RCC and hybrid oncocytic/chromophobe tumors (HOCT). In current review, we will collect available literature of these newly-described RCCs, analyze their clinical pathologic characteristics, discuss their morphologic and immunohistologic features, and finally summarize their molecular and genetic evidences. We expect this review would be beneficial for the understanding of RCCs, and eventually promote clinical management strategies.

Validation and utilization of a TFE3 break-apart FISH assay for Xp11.2 translocation renal cell carcinoma and alveolar soft part sarcoma

Background

Xp11.2 or TFE3 translocation renal cell carcinomas (RCC) and alveolar soft part sarcoma (ASPS) are characterized by chromosome translocations involving the Xp11.2 breakpoint resulting in transcription factor TFE3 gene fusions. The most common translocations documented in TFE3 RCCs are t(X;1) (p11.2;q21) and t(X;17) (p11.2;q25) which leads to fusion of TFE3 gene on Xp11.2 with PRCC or ASPL respectively. TFE3 immunohistochemistry (IHC) has been inconsistent over time due to background staining problems in part related to fixation issues. Karyotyping to detect TFE3 gene rearrangement requires typically unavailable fresh tissue. Reverse transcriptase-polymerase chain reaction (RT-PCR) is generally very challenging due to degradation of RNA in archival material. The study objective was to develop and validate a TFE3 break-apart fluorescence in situ hybridization (FISH) assay to confirm Xp11 translocation RCCs and ASPS.

Methods

Representative sections of formalin-fixed paraffin-embedded tissue blocks were selected in 40 possible cases. Approximately 60 tumor cells were analyzed in the targeted region. The validation of TFE3 FISH was done with 11 negative and two positive cases. Cut off for a positive result was validated as >7.15 % positive nuclei with any pattern of break-apart signals. FISH evaluation was done blinded of the immunohistochemical or karyotype data.

Results

Three out of forty cases were positive for the TFE3 break-apart signals by FISH. The negative cases were reported as clear cell RCC with papillary features (10), clear cell RCC with sarcomatoid areas (2), Papillary RCC with clear cell areas (9), Chromophobe RCC (2), RCC, unclassified type (3) and renal medullary carcinoma (1). 3 of the negative cases were consultation cases for renal tumor with unknown histology. Seven negative cases were soft tissue tumor suspicious for ASPS.

Conclusion

Our study validates the utility of TFE3 break-apart FISH on formalin-fixed paraffin-embedded tissue sections for diagnosis and confirmation of Xp11.2 translocation RCCs and ASPS.

Newly designed break-apart and ASPL-TFE3 dual-fusion FISH assay are useful in diagnosing Xp11.2 translocation renal cell carcinoma and ASPL-TFE3 renal cell carcinoma: a STARD-compliant article

The diagnosis of Xp11.2 translocation renal cell carcinoma (tRCC), which relies on morphology and immunohistochemistry (IHC), is often either missed in the diagnosis or misdiagnosed. To improve the accuracy of diagnosis of Xp11.2 tRCC and ASPL-TFE3 renal cell carcinoma (RCC), we investigated newly designed fluorescence in situ hybridization (FISH) probes (diagnostic accuracy study).Based on the genetic characteristics of Xp11.2 tRCC and the ASPL-TFE3 RCC, a new break-apart TFE3 FISH probe and an ASPL-TFE3 dual-fusion FISH probe were designed and applied to 65 patients with RCC who were <45 years old or showed suspicious microscopic features of Xp11.2 tRCC in our hospital. To test the accuracy of the probes, we further performed reverse transcriptase-polymerase chain reaction (PCR) on 8 cases for which frozen tissues were available.Among the 65 cases diagnosed with RCC, TFE3 IHC was positive in 24 cases. Twenty-two cases were confirmed as Xp11.2 tRCC by break-apart TFE3 FISH, and 6 of these cases were further diagnosed as ASPL-TFE3 RCC by ASPL-TFE3 dual-fusion FISH detection. Importantly, reverse transcriptase-PCR showed concordant results with the results of FISH assay in the 8 available frozen cases.The break-apart and ASPL-TFE3 dual-fusion FISH assay can accurately detect the translocation of the TFE3 gene and ASPL-TFE3 fusion gene and can thus serve as a valid complementary method for diagnosing Xp11.2 tRCC and ASPL-TFE3 RCC.

Molecular genetics and cellular features of TFE3 and TFEB fusion kidney cancers

Despite nearly two decades passing since the discovery of gene fusions involving TFE3 or TFEB in sporadic renal cell carcinoma (RCC), the molecular mechanisms underlying the renal-specific tumorigenesis of these genes remain largely unclear. The recently published findings of The Cancer Genome Atlas Network reported that five of the 416 surveyed clear cell RCC tumours (1.2%) harboured SFPQ-TFE3 fusions, providing further evidence for the importance of gene fusions. A total of five TFE3 gene fusions (PRCC-TFE3, ASPSCR1-TFE3, SFPQ-TFE3, NONO-TFE3, and CLTC-TFE3) and one TFEB gene fusion (MALAT1-TFEB) have been identified in RCC tumours and characterized at the mRNA transcript level. A multitude of molecular pathways well-described in carcinogenesis are regulated in part by TFE3 or TFEB proteins, including activation of TGFβ and ETS transcription factors, E-cadherin expression, CD40L-dependent lymphocyte activation, mTORC1 signalling, insulin-dependent metabolism regulation, folliculin signalling, and retinoblastoma-dependent cell cycle arrest. Determining which pathways are most important to RCC oncogenesis will be critical in discovering the most promising therapeutic targets for this disease.

Magnetic resonance imaging and computed tomography characteristics of renal cell carcinoma associated with Xp11.2 translocation/TFE3 gene fusion

PURPOSE

To characterize Xp11.2 translocation renal cell carcinoma (RCC) using magnetic resonance imaging (MRI) and computed tomography (CT).

METHODS

This study retrospectively collected the MRI and CT data of twelve patients with Xp11.2 translocation RCC confirmed by pathology. Nine cases underwent dynamic contrast-enhanced MRI (DCE-MRI) and 6 cases underwent CT, of which 3 cases underwent MRI and CT simultaneously. The MRI and CT findings were analyzed in regard to tumor position, size, hemorrhagic, cystic or necrotic components, calcification, tumor density, signal intensity and enhancement features.

RESULTS

The age of the 12 patients ranged from 13 to 46 years (mean age: 23 years). T2WI revealed heterogeneous intensity, hyper-intensity, and slight hypo-intensity in 6 cases, 2 cases, and 1 case, respectively. On DCE-MR images, mild, moderate, and marked rim enhancement of the tumor in the corticomedullary phase (CMP) were observed in 1, 6, and 2 cases, respectively. The tumor parenchyma showed iso-attenuation (n = 4) or slight hyper-attenuation (n = 1) compared to the normal renal cortex on non-contrast CT images. Imaging findings were suggestive of hemorrhage (n = 4) or necrosis (n = 8) in the tumors, and there was evidence of calcification in 8 cases by CT (n = 3) and pathology (n = 8). On dynamic contrast-enhanced CT images, 3 cases and 1 case manifested moderate and strong CMP enhancement, respectively. Nine tumors by MRI and 4 tumors by CT showed prolonged enhancement. Three neoplasms presented at stage I, 2 at stage II, 3 at stage III, and 4 at stage IV according the 2010 AJCC staging criteria.

CONCLUSIONS

XP11.2 translocation RCC should be considered when a child or young adult patient presents with a renal tumor with heterogeneous features such as hemorrhage, necrosis, cystic changes, and calcification on CT and MRI and/or is accompanied by metastatic evidence.

The preliminary experiences of translocation renal cell carcinoma and literature review

Xp11.2 translocation renal cell carcinoma (RCC) is rare and predominantly found in children and young adults. Because of the property of overexpressed transcription factor E3 (TFE3) fusion protein, immunohistochemical (IHC) staining with TFE3 antibody makes an excellent diagnostic tool. This study analyzed preliminary experiences of eight Xp11.2 translocation RCCs in our institution between 2007 and 2012. In four males and four females with a mean age of 28.4 years. Xp11.2 translocation RCCs were diagnosed. TFE3 IHC stain was positive in all tumor specimens. As the initial presentation, four patients suffered from abdominal pain, three cases had gross hematuria, and one case had hemoptysis caused by existing lung metastasis. The tumor was located in the right kidney (75%) with mean diameter of 5.85 ± 2.64 cm. Three cases (38%, 3/8) presented with lymph node metastasis at the time of diagnosis. In five cases (63%, 5/8), the initial diagnosis was Stage III and IV. Treatment included open surgery (one partial nephrectomy and five radical nephrectomies), cryoablation, immunotherapy, and target therapy. The mean follow-up time was 32 months. One patient died after 23.4 months of follow-up. The application of TFE3 IHC stain will improve the diagnostic accuracy for detecting XP11.2 translocation renal cell carcinoma. Surgery or cryoablation both had excellent prognosis in early stages. Although the disease is believed to be indolent, an increasingly aggressive clinical course should be kept in mind, especially for children and young adults.

TFE3 break-apart FISH has a higher sensitivity for Xp11.2 translocation-associated renal cell carcinoma compared with TFE3 or cathepsin K immunohistochemical staining alone: expanding the morphologic spectrum

Renal cell carcinoma (RCC) associated with Xp11.2 translocation is uncommon, characterized by several different translocations involving the TFE3 gene. We assessed the utility of break-apart fluorescence in situ hybridization (FISH) in establishing the diagnosis for suspected or unclassified cases with negative or equivocal TFE3 immunostaining by analyzing 24 renal cancers with break-apart TFE3 FISH and comparing the molecular findings with the results of TFE3 and cathepsin K immunostaining in the same tumors. Ten tumors were originally diagnosed as Xp11.2 RCC on the basis of positive TFE3 immunostaining, and 14 were originally considered unclassified RCCs with negative or equivocal TFE3 staining, but with a range of features suspicious for Xp11.2 RCC. Seventeen cases showed TFE3 rearrangement associated with Xp11.2 translocation by FISH, including all 13 tumors with moderate or strong TFE3 (n=10) or cathepsin K (n=7) immunoreactivity. FISH-positive cases showed negative or equivocal immunoreactivity for TFE3 or cathepsin K in 7 and 10 tumors, respectively (both=3). None had positive immunohistochemistry but negative FISH. Morphologic features were typical for Xp11.2 RCC in 10/17 tumors. Unusual features included 1 melanotic Xp11.2 renal cancer, 1 tumor with mixed features of Xp11.2 RCC and clear cell RCC, and other tumors mimicking clear cell RCC, multilocular cystic RCC, or high-grade urothelial carcinoma. Morphology mimicking high-grade urothelial carcinoma has not been previously reported in these tumors. Psammoma bodies, hyalinized stroma, and intracellular pigment were preferentially identified in FISH-positive cases compared with FISH-negative cases. Our results support the clinical application of a TFE3 break-apart FISH assay for diagnosis and confirmation of Xp11.2 RCC and further expand the histopathologic spectrum of these neoplasms to include tumors with unusual features. A renal tumor with pathologic or clinical features highly suggestive of translocation-associated RCC but exhibiting negative or equivocal TFE3 immunostaining should be evaluated by TFE3 FISH assay to fully assess this possibility.

Pediatric Renal Cell Carcinoma

Renal cell carcinomas are rare in children, and they show significant differences in their histology and pathogenesis when compared to those common in adults. The most common subtypes seen preferentially in children are the translocation-associated tumors, papillary renal cell carcinoma, renal medullary carcinoma, and oncocytic renal cell carcinoma following neuroblastoma. The histological diagnosis of renal cell carcinoma is made difficult by the considerable heterogeneity within and overlap between each of the above subtypes and by similarities to other pediatric renal neoplasms. While no effective therapies have yet been identified, there is considerable promise that the new Children's Oncology Group protocol will provide knowledge that will guide the future therapy of these lesions.