nephrometry score and survival outcomes in renal tumours

OBJECTIVE

The radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry score could be used to predict surgical outcomes and renal tumour aggressiveness. We aimed to analyse its associations with survival outcomes.

METHODS

We included 1368 patients with sporadic, unilateral and non-metastatic renal tumours who received curative nephrectomy in Zhongshan Hospital from January 2009 to September 2019. Radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry scores were assigned by three urologists based on preoperative CT/MRI scans. Correlations between parameters or sum of radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry scores, overall survival and recurrence-free survival were analysed by Kaplan-Meier analyses and the multivariate Cox regression model. We further compared survival outcomes between patients who received partial nephrectomy and patients who received radical nephrectomy.

RESULTS

We observed statistically significant associations between all components of radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry scores and oncologic outcomes, including R (radius) (overall survival, P < 0.001; recurrence-free survival , P < 0.001), E (exophytic/endophytic) (overall survival, P = 0.003; recurrence-free survival, P < 0.001), N (nearness) (overall survival, P = 0.063; recurrence-free survival, P < 0.001), A (anterior/posterior) (overall survival, P < 0.001; recurrence-free survival, P = 0.005), L (location) (overall survival, P = 0.008; recurrence-free survival, P < 0.001) and suffix 'h' (overall survival, P = 0.237; recurrence-free survival, P = 0.034). Kaplan-Meier curves of overall survival and recurrence-free survival rates were significantly different when stratified by radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry score complexity group (overall survival, P < 0.001; recurrence-free survival, P < 0.001). After adjusting for tumour stage and grade, radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry score as continuous variables was an adverse independent risk factor for survival outcomes [P = 0.027, hazard ratio (95% confidence interval) = 1.151 (1.016-1.303)] and recurrence-free survival [P < 0.001, hazard ratio (95% confidence interval) = 1.299 (1.125-1.501)]. For tumours with radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry scores of 4 and 5, partial nephrectomy showed a survival benefit than radical nephrectomy.

CONCLUSION

Both components and complexity groups of the radius-exophytic/endophytic-nearness-anterior/posterior-location nephrometry score are associated with survival outcomes in renal tumour patients.

WHO 2022 landscape of papillary and chromophobe renal cell carcinoma

The 5th edition of the WHO Classification of Tumours of the Urinary and Male Genital Systems contains relevant revisions and introduces a group of molecularly defined renal tumour subtypes. Herein we present the World Health Organization (WHO) 2022 perspectives on papillary and chromophobe renal cell carcinoma with emphasis on their evolving classification, differential diagnosis, and emerging entities. The WHO 2022 classification eliminated the type 1/2 papillary renal cell carcinoma (pRCC) subcategorization, given the recognition of frequent mixed tumour phenotypes and the existence of entities with a different molecular background within the type 2 pRCC category. Additionally, emerging entities such as biphasic squamoid alveolar RCC, biphasic hyalinising psammomatous RCC, papillary renal neoplasm with reverse polarity, and Warthin-like pRCC are included as part of the pRCC spectrum, while additional morphological and molecular data are being gathered. In addition to oncocytomas and chromophobe renal cell carcinoma (chRCC), a category of 'other oncocytic tumours' with oncocytoma/chRCC-like features has been introduced, including emerging entities, most with TSC/mTOR pathway alterations (eosinophilic vacuolated tumour and so-called 'low-grade' oncocytic tumour), deserving additional research. Eosinophilic solid and cystic RCC was accepted as a new and independent tumour entity. Finally, a highly reproducible and clinically relevant universal grading system for chRCC is still missing and is another niche of ongoing investigation. This review discusses these developments and highlights emerging morphological and molecular data relevant for the classification of renal cell carcinoma.

How we approach paediatric renal tumour core needle biopsy in the setting of preoperative chemotherapy: A Review from the SIOP Renal Tumour Study Group

The International Society of Paediatric Oncology Renal Tumour Study Group (SIOP-RTSG) advocate treating children with Wilms tumour (WT) with preoperative chemotherapy, whereas the Renal Tumor Committee of the Children's Oncology Group (COG) advocates primary nephrectomy (without biopsy) when feasible. Successive SIOP-RTSG trial protocols recommended pretreatment biopsy of children with unilateral tumours only where there were features to suggest an increased probability of a non-WT requiring a change in management. The UK experience in the SIOP WT 2001 trial showed that an alternate approach of performing biopsies on all children with renal tumour masses to determine histology at diagnosis rarely changes management, and can result in misdiagnosis (particularly patients in the age range typical for WT). Although a more selective approach to biopsy has been routine practice in all other countries participating in SIOP-RTSG trials, there was variation between national groups. To address this variation and provide evidence-based recommendations for the indications and recommended approach to renal tumour biopsy within the SIOP paradigm, an international, multidisciplinary working group of SIOP-RTSG members was convened. We describe the resulting recommendations of this group, which are to be incorporated in the ongoing SIOP-RTSG UMBRELLA study.

Papillary renal cell carcinoma: current and controversial issues

PURPOSE OF THE REVIEW

Papillary renal cell carcinoma (pRCC) is the second most frequent renal cancer subtype and represents 15-20% of all RCC. Classification of pRCC is changing because novel tumour entities have been discovered in the last years. In this review, we summarise recent studies relevant for the understanding of the molecular complexity and the broader differential diagnosis of pRCC.

RECENT FINDINGS

It has been 25 years ago, that pRCC was morphologically subdivided into type 1 and type 2. Recently described tumour entities in the 2022 WHO classification challenged this concept and allow a new view on the molecular background in pRCC. Biphasic hyalinizing psammomatous RCC and papillary renal neoplasm with reversed polarity are emerging tumour entities derived from the new concept of molecularly defined RCC subtypes. Immune checkpoint inhibition and tyrosine kinase inhibitors have been introduced as the new backbone in the first-line treatment of advanced pRCCs. To identify novel targeted treatments for patients with pRCC it is crucial to investigate the specific molecular background of pRCC considering emerging pRCC subtypes.

SUMMARY

In the future, a deeper understanding of the correlation between molecular aberrations and new pRCC subtypes may improve the classification of pRCC patients and could reveal potential predictive biomarkers for each subgroup.

Altered Tissue and Plasma Levels of Fibroblast Activation Protein-α (FAP) in Renal Tumours

Simple Summary

Malignant epithelial tumour’s behaviour in the kidney has traditionally been analysed attending to different prognostic parameters focussed on the proliferating neoplastic cell. This is the case of renal cell carcinoma (RCC), in which a large tumour diameter, high histological grade, and the presence of necrosis, among other factors, have been related with a high risk of distant metastasis and, therefore, worse survival. Recently, several elements of the tumour microenviroment, such as cancer-associated fibroblasts (CAFs), are being studied in order to develop more accurate diagnostic and therapeutic approaches. We present data that support that the fibroblast activation protein-α (FAP), a CAF biomarker, provides interesting information both in tumour tissues and in plasma from patients with RCC.

Abstract

(1) Background: Renal cell carcinoma (RCC) is a heterogeneous and complex disease with only partial response to therapy, high incidence of metastasis and recurrences, and scarce reliable biomarkers indicative of progression and survival. Cancer-associated fibroblasts (CAFs) play an important role supporting and promoting renal cancer progression. (2) Methods: In this study, we analysed fibroblast activation protein-α (FAP) immunohistochemical expression and its soluble isoform (sFAP) in tumour tissues and plasma from 128 patients with renal tumours. (3) Results: FAP is expressed in the cell surface of CAFs of the tumour centre and infiltrating front from clear cell renal cell carcinomas (CCRCC, n = 89), papillary renal cell carcinomas (PRCC, n = 21), and chromophobe renal cell carcinomas (ChRCC, n = 8), but not in the benign tumour renal oncocytoma (RO, n = 10). A high expression of FAP and low levels sFAP are significantly associated with high tumour diameter, high grade, and high pT stage, lymph node invasion, development of early metastases, and worse 5-year cancer specific survival of CCRCC patients. (4) Conclusions: These findings corroborate the potential usefulness of FAP immunohistochemistry and plasma sFAP as a biomarker of CCRCC progression and point to CAF-related proteins as promising immunohistochemical biomarkers for the differential diagnosis of ChRCC and RO.

Individualized robotic organ-sparing surgery in a paediatric case of renal perivascular epithelioid cell tumour

BACKGROUND

Perivascular epithelioid cell tumours (PEComas) represent a rare group of mesenchymal tumours with an unpredictable outcome. They are usually observed in middle-aged women whilst they are very rare in children, with limited cases described. Due to the rare anatomical location in kidneys, a correct diagnosis and treatment is really challenging.

METHODS

We observed and treated a case of kidney's PEComa in a 14-year-old boy.

RESULTS

An individualized approach based on anatomical (3D CT-reconstructions) and histopathological (US-guided preliminary biopsy) features lead us to perform a successful robotic-sparing surgery enabling the preservation of two-thirds of the kidney involved.

CONCLUSIONS

A meticulous preoperative planning in selected patients can lead to a minimally invasive approach even in some paediatric kidney's neoplasms.

MicroRNAs as markers to monitor endothelin-1 signalling and potential treatment in renal disease: Carcinoma - proteinuric damage - toxicity

This review highlights new developments in miRNA as diagnostic and surveillance tools in diseases damaging the renal proximal tubule mediated by endothelin in the field of renal carcinoma, proteinuric kidney disease and tubulotoxicity. A new mechanism in the miRNA regulation of proteins leads to the binding of the miRNA directly to the DNA with premature transcriptional termination and hence the formation of truncated protein isoforms (Mxi2, Vim3). These isoforms are mediated through miRNA15a or miRNA 498, respectively. ET-1 can activate a cytoplasmic complex consisting of NF-κB p65, MAPK p38α, and PKCα. Consequently, PKCα does not transmigrate into the nucleus, which leads to the loss of suppression of a primiRNA15a, maturation of this miRNA in the cytoplasm, tubular secretion and detectability in the urine. This mechanism has been shown in renal cell carcinoma and in proteinuric disease as a biomarker for the activation of the signalling pathway. Similarly, ET-1 induced miRNA 498 transmigrates into the nucleus to form the truncated protein Vim3, which is a biomarker for the benign renal cell tumour, oncocytoma. In tubulotoxicity, ET-1 induced miRNa133a down-regulating multiple-drug-resistant related protein-2, relevant for proteinuric and cisplatin/cyclosporine A toxicity. Current advantages and limitations of miRNAs as urinary biomarkers are discussed.

The dual PI3K/mTOR inhibitor GSK2126458 is effective for treating solid renal tumours in Tsc2+/- mice through suppression of cell proliferation and induction of apoptosis

Tuberous sclerosis (TSC) is an inherited tumour syndrome caused by mutations in TSC1 or TSC2 that lead to aberrant activation of mTOR. Tumour responses in TSC patients to rapamycin, an allosteric inhibitor of mTOR, or its analogs are partial and reversible probably due to feedback activation of Akt. In this study, we examined the efficacy of GSK2126458, an ATP-competitive dual inhibitor of PI3K/mTOR, in comparison to rapamycin for treatment of renal tumours in genetically engineered Tsc2^+/- mice. We found that both GSK2126458 and rapamycin caused significant reduction in number and size of solid renal tumours. GSK2126458 also significantly reduced the number and size of all lesions (cystic, papillary and solid) although to a lesser extent compared to rapamycin. GSK2126458 inhibited both PI3K and mTOR while rapamycin exerted stronger inhibitory effect on mTORC1 in renal tumours. Furthermore, GSK2126458 and rapamycin suppressed proliferation of tumour cells. Importantly, GSK2126458 increased apoptosis of solid tumours but rapamycin did not. Further investigations are therefore needed to test whether rapamycin in combination with GSK2126458 could promote apoptosis and thus improve therapy of TSC-associated renal tumours.

Indications for biopsy and the current status of focal therapy for renal tumours

The increased detection of small renal masses (SRMs) has focused attention on their uncertain natural history. The development of treatment alternatives and the discovery of biologically targeted drugs have also raised interest. Renal mass biopsies (RMBs) have a crucial role as they provide the pathological, molecular and genetic information needed to classify these lesions and guide clinical management. The improved accuracy has improved our knowledge of the behaviour of different tumour histologies and opened the potential for risk-adapted individualized treatment approaches. To date, studies have demonstrated that percutaneous ablation is an effective therapy with acceptable outcomes and low risk in the appropriate clinical setting. Although partial nephrectomy (PN) is still considered the standard treatment for SRM, percutaneous ablation is increasingly being performed and if long-term efficacy is sustained, it may have a wider application for SRMs after biopsy characterization.

Xp 11.2 translocation renal carcinoma in young adults; recently classified distinct subtype

Background

XP11.2 renal translocation carcinomas are often encountered in paediatric group of patients where they are believed to be rather indolent. They are rare but more aggressive in young adults. They are slow growing, sometimes without characteristic symptoms and their biologic behaviour is uncertain.

Case report

We report two cases of this type of tumour in Slovenian young adult males with long and unusual history. Tumours were confirmed imunohistologically by positive reaction for CD10, P504S and TFE3.

Conclusions

According to the indications in the literature prognosis of these tumours in young adults depends upon the stage. It seems that cysts, haematomas and necrosis around the kidney are often encountered in these tumours. In advanced stage with lymph nodes involvement or distant metastases, the prognosis is poor. Surgery seems to be basic mode of therapy.