Nephron Sparing Treatment (NEST) for Small Renal Masses: A Feasibility Cohort-embedded Randomised Controlled Trial Comparing Percutaneous Cryoablation and Robot-assisted Partial Nephrectomy.

There is a paucity of high-level evidence on small renal mass (SRM) management, as previous classical randomised controlled trials (RCTs) failed to meet accrual targets. Our objective was to assess the feasibility of recruitment to a cohort-embedded RCT comparing cryoablation (CRA) to robotic partial nephrectomy (RPN). A total of 200 participants were recruited to the cohort, of whom 50 were enrolled in the RCT. In the CRA intervention arm, 84% consented (95% confidence interval [CI] 64-95%) and 76% (95% CI 55-91%) received CRA; 100% (95% CI 86-100%) of the control arm underwent RPN. The retention rate was 90% (95% CI 79-96%) at 6 mo. In the RPN group 2/25 (8%) were converted intra-operative to radical nephrectomy. Postoperative complications (Clavien-Dindo grade 1-2) occurred in 12% of the CRA group and 29% of the RPN group. The median length of hospital stay was shorter for CRA (1 vs 2 d; p = 0.019). At 6 mo, the mean change in renal function was -5.0 ml/min/1.73 m2 after CRA and -5.8 ml/min/1.73 m2 after RPN. This study demonstrates the feasibility of a cohort-embedded RCT comparing CRA and RPN. These data can be used to inform multicentre trials on SRM management. PATIENT SUMMARY: We assessed whether patients with a small kidney tumour would consent to a trial comparing two different treatments: cryoablation (passing small needles through the skin to freeze the kidney tumour) and surgery to remove part of the kidney. We found that most patients agreed and a full trial would therefore be feasible.

Epitheloid Angiomyolipomas of the Kidney: Rare Renal Tumors Associated With Poor Prognoses.

OBJECTIVE: To demonstrate the clinical spectrum and challenges associated with clinical management of epitheloid angiomyolipomas (eAML). METHODS: We retrospectively reviewed the surgical database of a high-volume tertiary kidney cancer center from 2015 to 2020 to identify cases with a final histological diagnosis of eAML. Descriptive analysis of all cases was conducted. RESULTS: Five surgical cases of eAMLs were identified. Two of which have had no tumor recurrence since surgery, and three patients passed away due to disease progression. CONCLUSION: eAML are rare renal tumors which the World Health Organisation (5th Edition, 2022) and International Classification of Diseases for Oncology classify as having unspecified, borderline, or uncertain behavior. Here, we report that can also demonstrate aggressive behavior with fatal consequences. Post-operative follow-up should be recommended for all, with shorter intervals for patients with poor prognostic factors.

Mapping single-cell transcriptomes in the intra-tumoral and associated territories of kidney cancer.

Tumor behavior is intricately dependent on the oncogenic properties of cancer cells and their multi-cellular interactions. To understand these dependencies within the wider microenvironment, we studied over 270,000 single-cell transcriptomes and 100 microdissected whole exomes from 12 patients with kidney tumors, prior to validation using spatial transcriptomics. Tissues were sampled from multiple regions of the tumor core, the tumor-normal interface, normal surrounding tissues, and peripheral blood. We find that the tissue-type location of CD8+ T cell clonotypes largely defines their exhaustion state with intra-tumoral spatial heterogeneity that is not well explained by somatic heterogeneity. De novo mutation calling from single-cell RNA-sequencing data allows us to broadly infer the clonality of stromal cells and lineage-trace myeloid cell development. We report six conserved meta-programs that distinguish tumor cell function, and find an epithelial-mesenchymal transition meta-program highly enriched at the tumor-normal interface that co-localizes with IL1B-expressing macrophages, offering a potential therapeutic target.

Defining the origin, evolution, and immune composition of SDH-deficient renal cell carcinoma.

Succinate dehydrogenase (SDH)-deficient renal cell carcinoma represents a rare subtype of hereditary kidney cancer. Clinical diagnosis can be challenging and there is little evidence to guide systemic therapeutic options. We performed genomic profiling of a cohort of tumors through the analysis of whole genomes, transcriptomes, as well as flow cytometry and immunohistochemistry in order to gain a deeper understanding of their molecular biology. We find neutral evolution after early tumor activation with a lack of secondary driver events. We show that these tumors have epithelial derivation, possibly from the macula densa, a specialized paracrine cell of the renal juxtaglomerular apparatus. They subsequently develop into immune excluded tumors. We provide transcriptomic and protein expression evidence of a highly specific tumor marker, PAPPA2. These translational findings have implications for the diagnosis and treatment for this rare tumor subtype.

Renal tumouroids: challenges of manufacturing 3D cultures from patient derived primary cells.

Recent advancements in 3D in vitro culture have allowed for the development of cancer tissue models which accurately recapitulate the tumour microenvironment. Consequently, there has been increased innovation in therapeutic drug screening. While organoid cultures show great potential, they are limited by the time scale of their growth in vitro and the dependence upon commercial matrices, such as Matrigel, which do not allow for manipulations of their composition or mechanical properties. Here, we show a straightforward approach for the isolation and culture of primary human renal carcinoma cells and matched non-affected kidney. This approach does not require any specific selection for cancer cells, and allows for their direct culture in amenable 3D collagen-based matrices, with the preservation of cancer cells as confirmed by NGS sequencing. This method allows for culture of patient-derived cancer cells in 3D microenvironment, which can be used for downstream experimentation such as investigation of cell-matrix interaction or drug screening.

Growth and renal function dynamics of renal oncocytomas in patients on active surveillance.

OBJECTIVES: To study the natural history of renal oncocytomas and address indications for intervention by determining how growth is associated with renal function over time, the reasons for surgery and ablation, and disease-specific survival. PATIENTS AND METHODS: The study was conducted in a retrospective cohort of consecutive patients with renal oncocytoma on active surveillance reviewed at the Specialist Centre for Kidney Cancer at the Royal Free London NHS Foundation Trust (2012 to 2019). Comparison between groups was performed using Mann-Whitney U-tests and chi-squared tests. A mixed-effects model with a random intercept for patient was used to study the longitudinal association between tumour size and estimated glomerular filtration rate (eGFR). RESULTS: Longitudinal data from 98 patients with 101 lesions were analysed. Most patients were men (68.3%) and the median (interquartile range [IQR]) age was 69 (13) years. The median (IQR) follow-up was 29 (26) months. Most lesions were small renal masses, and 24% measured over 4 cm. Over half (64.4%) grew at a median (IQR) rate of 2 (4) mm per year. No association was observed between tumour size and eGFR over time (P = 0.871). Nine lesions (8.9%) were subsequently treated. Two deaths were reported, neither were related to the diagnosis of renal oncocytoma. CONCLUSION: Natural history data from the largest active surveillance cohort of renal oncocytomas to date show that renal function does not seem to be negatively impacted by growing oncocytomas, and confirms clinical outcomes are excellent after a median follow-up of over 2 years. Active surveillance should be considered the 'gold standard' management of renal oncocytomas up to 7cm.

Pattern, timing and predictors of recurrence after surgical resection of chromophobe renal cell carcinoma.

PURPOSE: Currently there are no specific guidelines for the post-operative follow-up of chromophobe renal cell carcinoma (chRCC). We aimed to evaluate the pattern, location and timing of recurrence after surgery for non-metastatic chRCC and establish predictors of recurrence and cancer-specific death. METHODS: Retrospective analysis of consecutive surgically treated non-metastatic chRCC cases from the Royal Free London NHS Foundation Trust (UK, 2015-2019) and the international collaborative database RECUR (15 institutes, 2006-2011). Kaplan-Meier curves were plotted. The association between variables of interest and outcomes were analysed using univariate and multivariate Cox proportional hazards regression models with shared frailty for data source. RESULTS: 295 patients were identified. Median follow-up was 58 months. The five and ten-year recurrence-free survival rates were 94.3% and 89.2%. Seventeen patients (5.7%) developed recurrent disease, 13 (76.5%) with distant metastases. 54% of metastatic disease diagnoses involved a single organ, most commonly the bone. Early recurrence (< 24 months) was observed in 8 cases, all staged ≥ pT2b. 30 deaths occurred, of which 11 were attributed to chRCC. Sarcomatoid differentiation was rare (n = 4) but associated with recurrence and cancer-specific death on univariate analysis. On multivariate analysis, UICC/AJCC T-stage ≥ pT2b, presence of coagulative necrosis, and positive surgical margins were predictors of recurrence and cancer-specific death. CONCLUSION: Recurrence and death after surgically resected chRCC are rare. For completely excised lesions ≤ pT2a without coagulative necrosis or sarcomatoid features, prognosis is excellent. These patients should be reassured and follow-up intensity curtailed.

Radiomics to better characterize small renal masses.

PURPOSE: Radiomics is a specific field of medical research that uses programmable recognition tools to extract objective information from standard images to combine with clinical data, with the aim of improving diagnostic, prognostic, and predictive accuracy beyond standard visual interpretation. We performed a narrative review of radiomic applications that may support improved characterization of small renal masses (SRM). The main focus of the review was to identify and discuss methods which may accurately differentiate benign from malignant renal masses, specifically between renal cell carcinoma (RCC) subtypes and from angiomyolipoma without visible fat (fat-poor AML) and oncocytoma. Furthermore, prediction of grade, sarcomatoid features, and gene mutations would be of importance in terms of potential clinical utility in prognostic stratification and selecting personalised patient management strategies. METHODS: A detailed search of original articles was performed using the PubMed-MEDLINE database until 20 September 2020 to identify the English literature relevant to radiomics applications in renal tumour assessment. In total, 42 articles were included in the analysis in 3 main categories related to SRM: prediction of benign versus malignant SRM, subtypes, and nuclear grade, and other features of aggressiveness. CONCLUSION: Overall, studies reported the superiority of radiomics over expert radiological assessment, but were mainly of retrospective design and therefore of low-quality evidence. However, it is clear that radiomics is an attractive modality that has the potential to improve the non-invasive diagnostic accuracy of SRM imaging and prediction of its natural behaviour. Further prospective validation studies of radiomics are needed to augment management algorithms of SRM.

The anti-angiogenic tyrosine kinase inhibitor Pazopanib kills cancer cells and disrupts endothelial networks in biomimetic three-dimensional renal tumouroids.

Pazopanib is a tyrosine kinase inhibitor used to treat renal cell carcinoma. Few in vitro studies investigate its effects towards cancer cells or endothelial cells in the presence of cancer. We tested the effect of Pazopanib on renal cell carcinoma cells (CAKI-2,786-O) in two-dimensional and three-dimensional tumouroids made of dense extracellular matrix, treated in normoxia and hypoxia. Finally, we engineered complex tumouroids with a stromal compartment containing fibroblasts and endothelial cells. Simple CAKI-2 tumouroids were more resistant to Pazopanib than 786-O tumouroids. Under hypoxia, while the more 'resistant' CAKI-2 tumouroids showed no decrease in viability, 786-O tumouroids required higher Pazopanib concentrations to induce cell death. In complex tumouroids, Pazopanib exposure led to a reduction in the overall cell viability (p < 0.0001), disruption of endothelial networks and direct killing of renal cell carcinoma cells. We report a biomimetic multicellular tumouroid for drug testing, suitable for agents whose primary target is not confined to cancer cells.

An overview of study designs.

The numbers of clinical trials have increased exponentially over the last decade, amplifying the pressure to select an appropriate study design to obtain reliable and valid evidence. The ability to find, critically appraise and use evidence to develop new interventions is fundamental to evidence-based medicine. Different study designs have their own advantages and disadvantages, and provide different evidentiary value. This article provides an overview of clinical trials, illustrating that, ultimately, the study design chosen needs to meet experimental and funding limitations, while minimising error.

Complex Open Pyeloplasty in a Pelvic Kidney.

A pelvic kidney occurs in between 1 in 2200 and 1 in 3000 people,1 due to failure of ascent during development. It is commonly asymptomatic and usually functions normally. Pelvic ureteral junction obstruction can either be congenital or acquired, and is characterized by intrinsic stenosis or extrinsic compression of the ureter at the junction with the pelvicalyceal renal system. This can cause symptomatic or asymptomatic hydronephrosis. We describe the complex case and management of a patient with a massive pelvic ureteral junction obstruction in a pelvic kidney.

Outcomes of Renal Tumors Treated by Image-Guided Percutaneous Cryoablation: Immediate and 3- and 5-Year Outcomes at a Regional Center.

OBJECTIVE. The purpose of this study was to evaluate the immediate and 3- and 5-year outcomes of patients with clinical stage T1 (cT1) biopsy-proven renal cell carcinoma (RCC) treated by image-guided percutaneous cryoablation at a regional interventional oncology center. MATERIALS AND METHODS. A prospectively maintained local interventional radiology database identified patients with cT1 RCC lesions that were treated by percutaneous cryoablation. Technical success, procedural complications (graded using the Clavien-Dindo classification system), and the residual unablated tumor rate were collated. Local tumor progression-free survival was estimated using Kaplan-Meier estimates. RESULTS. A total of 180 patients with 185 separate cT1 RCC lesions were identified. Mean patient age was 68.4 years (range, 34.1-88.9 years) and 52 patients (28.9%) were women. There were 168 (90.8%) and 17 (9.2%) cT1a and cT1b lesions, respectively, with a mean lesion size of 28.5 mm (range, 11-58 mm). Technical success was achieved in 183 of 185 (98.9%) patients. The major complication rate (Clavien-Dindo classification ≥ grade III) was 2.2% (four out of 185). Residual unablated tumor on the first follow-up scan was identified in four of 183 tumors (2.2%). Estimated local tumor progression-free survival at 3 and 5 years was 98.3% and 94.9%, respectively. No distant metastases or deaths attributable to RCC occurred. Mean estimated glomerular filtration rate (eGFR) before the procedure was 72.4 ± 18.5 (SD) mL/min/1.73 m2 and this was not statistically significantly different after the procedure (69.7 ± 18.8 mL/min/1.73 m2), at 1 year (70.7 ± 16.4 mL/min/1.73 m2), or at 2 years (69.8 ± 18.9 mL/min/1.73 m2) (p > 0.05). CONCLUSION. These data add to the accumulating evidence that image-guided cryoablation is an efficacious treatment for selected cT1 RCC with a low complication rate and ro bust 3- and 5-year outcomes.

Guideline adherence for the surgical treatment of T1 renal tumours correlates with hospital volume: an analysis from the British Association of Urological Surgeons Nephrectomy Audit.

OBJECTIVE: To assess European Association of Urology guideline adherence on the surgical management of patients with T1 renal tumours and the effects of centralisation of care. PATIENTS AND METHODS: Retrospective data from all kidney tumours that underwent radical nephrectomy (RN) or partial nephrectomy (PN) in the period 2012-2016 from the British Association of Urological Surgeons Nephrectomy Audit were retrieved and analysed. We assessed total surgical hospital volume (HV; RN and PN performed) per centre, PN rates, complication rates, and completeness of data. Descriptive analyses were performed, and confidence intervals were used to illustrate the association between hospital volume and proportion of PN. Chi- squared and Cochran-Armitage trend tests were used to evaluate differences and trends. RESULTS: In total, 13 045 surgically treated T1 tumours were included in the analyses. Over time, there was an increase in PN use (39.7% in 2012 to 44.9% in 2016). Registration of the Preoperative Aspects and Dimensions Used for an Anatomical (PADUA) complexity score was included in March 2016 and documented in 39% of cases. Missing information on postoperative complications appeared constant over the years (8.5-9%).  A clear association was found between annual HV and the proportion of T1 tumours treated with PN rather than RN (from 18.1% in centres performing <25 cases/year [lowest volume] to 61.8% in centres performing ≥100 cases/year [high volume]), which persisted after adjustment for PADUA complexity. Overall and major (Clavien-Dindo grade ≥III) complication rate decreased with increasing HV (from 12.2% and 2.9% in low-volume centres to 10.7% and 2.2% in high-volume centres, respectively), for all patients including those treated with PN. CONCLUSION: Closer guideline adherence was exhibited by higher surgical volume centres. Treatment of T1 tumours using PN increased with increasing HV, and was accompanied by an inverse association of HV with complication rate. These results support the centralisation of kidney cancer specialist cancer surgical services to improve patient outcomes.

Added value of diffusion-weighted images and dynamic contrast enhancement in multiparametric magnetic resonance imaging for the detection of clinically significant prostate cancer in the PICTURE trial.

OBJECTIVE: To determine the additional diagnostic value of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced imaging (DCE) in men requiring a repeat biopsy within the PICTURE study. PATIENTS AND METHODS: PICTURE was a paired-cohort confirmatory study in which 249 men who required further risk stratification after a previous non-magnetic resonance imaging (MRI)-guided transrectal ultrasonography-guided biopsy underwent a 3-Tesla (3T) multiparametic (mp)MRI consisting of T2-weighted imaging (T2W), DWI and DCE, followed by transperineal template prostate mapping biopsy. Each mpMRI was reported using a LIKERT score in a sequential blinded manner to generate scores for T2W, T2W+DWI and T2W+DWI+DCE. Area under the receiver-operating characteristic curve (AUROC) analysis was performed to compare the diagnostic accuracy of each combination. The threshold for a positive mpMRI was set at a LIKERT score ≥3. Clinically significant prostate cancer was analysed across a range of definitions including UCL/Ahmed definition 1 (primary definition), UCL/Ahmed definition 2, any Gleason ≥3 + 4 and any Gleason ≥4 + 3. RESULTS: Of 249 men, sequential MRI reporting was available for 246. There was a higher rate of equivocal lesions (44.6%) using T2W alone compared to the addition of DWI (23.9%) and DCE (19.8%). Using the primary definition of clinically significant disease, there was no significant difference in the overall accuracy between T2W, with an AUROC of 0.74 (95% confidence interval [CI] 0.68-0.80), T2W+DWI at 0.76 (95% CI 0.71-0.82), and T2W+DWI+DCE, with an AUROC of 0.77 (95% CI 0.71-0.82; P = 0.55). The AUROC values remained comparable using other definitions of clinically significant disease including UCL/Ahmed definition 2 (P = 0.79), Gleason ≥3 + 4 (P = 0.53) and Gleason ≥4 + 3 (P = 0.53). CONCLUSIONS: Using 3T MRI, a high level of diagnostic accuracy can be achieved using T2W as a single parameter in men with a prior biopsy; however, such a strategy can lead to a higher rate of equivocal lesions.

Acceptability and feasibility study of patient-specific 'tumouroids' as personalised treatment screening tools: Protocol for prospective tissue and data collection of participants with confirmed or suspected renal cell carcinoma.

INTRODUCTION: 'Personalised medicine' aims to tailor interventions to the individual, and has become one of the fastest growing areas of cancer research. One of these approaches is to harvest cancer cells from patients and grow them in the laboratory, which can then be subjected to treatments and the response assessed. We have developed a 3D tumour model with a complex protein matrix that mimics the tumour stroma, cell to cell and cell-matrix interactions seen in vivo, called a tumouroid. In this study, we test the acceptability and feasibility of using this model to establish patient-derived tumouroids. METHODS AND ANALYSIS: This is a first in-human study using prospective tissue and data collection of adult participants with confirmed or suspected renal cell carcinoma. The goals of the study are to assess patient acceptability to the use of patient-derived tumour models for future treatment decisions, and to assess the feasibility of generating patient-specific renal cancer tumouroids that can be challenged with drugs. These goals will be realised through the collection of tumour samples (expected n = 10), participant-completed questionnaires (expected n = 10), and in-depth semi-structured interviews with patients (expected n = 5). Collected multiregional tumour samples will be dissociated to isolate primary cells which are then expanded in vitro and incorporated into tumouroids. Drug challenge will ensue and the response will be categorised into "responder", "weak responder", and "non-responder". Statistical analysis will be descriptive. ETHICS AND DISSEMINATION: The study has ethical approval (REC reference 17/LO/1744). Findings will be made available to patients, clinicians, funders, and the National Health Service (NHS) through presentations at national and international meetings, peer-reviewed publications, social media and patient support groups. TRIAL REGISTRATION: Registered on ClinicalTrials.gov (NCT03300102).

First-in-human in vivo non-invasive assessment of intra-tumoral metabolic heterogeneity in renal cell carcinoma.

Intratumoral genetic heterogeneity and the role of metabolic reprogramming in renal cell carcinoma (RCC) have been extensively documented. However, the distribution of these metabolic changes within the tissue has not been explored. We report on the first-in-human in vivo non-invasive metabolic interrogation of RCC using hyperpolarized carbon-13 (13C) magnetic resonance imaging (HP-MRI) and describe the validation of in vivo lactate metabolic heterogeneity against multi-regional ex vivo mass spectrometry. HP-MRI provides an in vivo assessment of metabolism and provides a novel opportunity to safely and non-invasively assess cancer heterogeneity.

Protocol for a feasibility study of a cohort embedded randomised controlled trial comparing NEphron Sparing Treatment (NEST) for small renal masses.

INTRODUCTION: Small renal masses (SRMs; ≤4 cm) account for two-thirds of new diagnoses of kidney cancer, the majority of which are incidental findings. The natural history of the SRM seems largely indolent. There is an increasing concern regarding surgical overtreatment and the associated health burden in terms of morbidity and economy. Observational data support the safety and efficacy of percutaneous cryoablation but there is an unmet need for high-quality evidence on non-surgical management options and a head-to-head comparison with standard of care is lacking. Historical interventional trial recruitment difficulties demand novel study conduct approaches. We aim to assess if a novel trial design, the cohort embedded randomised controlled trial (RCT), will enable carrying out such a comparison. METHODS AND ANALYSIS: Single-centre prospective cohort study of adults diagnosed with SRM (n=200) with an open label embedded interventional RCT comparing nephron sparing interventions. Cohort participants will be managed at patient and clinicians' discretion and agree with longitudinal clinical data and biological sample collection, with invitation for trial interventions and participation in comparator control groups. Cohort participants with biopsy-proven renal cell carcinoma eligible for both percutaneous cryoablation and partial nephrectomy will be randomly selected (1:1) and invited to consider percutaneous cryoablation (n=25). The comparator group will be robotic partial nephrectomy (n=25). The primary outcome of this feasibility study is participant recruitment. Qualitative research techniques will assess barriers and recruitment improvement opportunities. Secondary outcomes are participant trial retention, health-related quality of life, treatment complications, blood transfusion rate, intensive care unit admission and renal replacement requirement rates, length of hospital stay, time to return to pre-treatment activities, number of work days lost, and health technologies costs. ETHICS AND DISSEMINATION: Ethical approval has been granted (UK HRA REC 19/EM/0004). Study outputs will be presented and published. TRIAL REGISTRATION: ISRCTN18156881; Pre-results.