Five-year analysis of a multi-institutional prospective clinical trial of delayed intervention and surveillance for small renal masses: the DISSRM registry

Predictive factors for recurrence and outcomes in T1a renal cell carcinoma: Analysis of the INMARC (International Marker Consortium for Renal Cancer) database

OBJECTIVE

Stage migration in renal cell carcinoma (RCC) has led to an increasing proportion of diagnosed small renal masses. Emerging knowledge regarding heterogeneity of RCC histologies and consequent impact on prognosis led us to further explore outcomes and predictive factors in surgically-treated T1a RCC.

METHODS

The INMARC database was queried for T1aN0M0 RCC. Patients were stratified into groups based on recurrence. Primary outcome was overall survival (OS). Multivariable analyses (MVA) were performed for factors associated with recurrence, cancer-specific (CSM), and all-cause mortality (ACM). Kaplan-Meier analyses (KMA) assessed survival by histology and grade. Subset analysis for time to recurrence was conducted for grade and histologic groups and compared with recent AUA follow-up guidelines [low-risk (AUA-LR), intermediate-risk (AUA-IR), high-risk (AUA-HR), and very-high risk (AUA-VHR) groups].

RESULTS

We analyzed 1,878 patients (median follow-up 35.2 months); 101 (5.4%) developed recurrence. MVA for recurrence demonstrated increasing age (P = 0.026), male sex (P = 0.043), diabetes (P = 0.007), high/unclassified grade (P < 0.001-0.007), and variant histology (P = 0.017) as independent risk factors for increased risk, while papillary (P = 0.016) and chromophobe (P = 0.049) were associated with decreased risk. MVA identified high/unclassified grade (P = 0.003-0.004) and pT3a upstaging (P = 0.043) as predictive factors for worsened risk of CSM while papillary (P = 0.034) was associated with improved risk. MVA for ACM demonstrated increasing age (P < 0.001), non-white (P < 0.001), high-grade (P = 0.022), variant histology (P = 0.049), recurrence (P = 0.004), and eGFR<45 at last follow-up (P < 0.001) to be independent risk factors. KMA comparing clear cell, chromophobe, papillary, and variant RCC revealed significant differences for 5-year CSS (P = 0.018) and RFS (P < 0.001), but not OS (P = 0.34). Median time to recurrence was 23.8 months for low-grade (AUA-LR), 17.3 months for high-grade (AUA-IR), 18 months for pT3a upstaging (AUA-HR), and 12 months for variant histology (AUA-VHR; P < 0.001).

CONCLUSION

We noted differential outcomes in T1a RCC based on histology and grade for recurrence and CSM, while renal functional decline in addition to pathological factors and recurrence were predictive for ACM. Our findings support recently promulgated AUA follow-up guidelines for low-grade and variant histology pT1a RCC, but call for consolidation of follow-up protocols for high-grade pT1a and pT3a upstaged patients, with intensification of frequency of imaging follow-up in pT1a high-grade RCC.

Renal cell carcinoma

The landscape of the management of renal cell carcinoma has evolved substantially in the last decade, leading to improved survival in localised and advanced disease. We review the epidemiology, pathology, and diagnosis of renal cell carcinoma and discuss the evidence for current management strategies from localised to metastatic disease. Developments in adjuvant therapies are discussed, including use of pembrolizumab-the first therapy to achieve overall survival benefit in the adjuvant setting. The treatment of advanced disease, including landmark trials that have established immune checkpoint inhibition as a standard of care, are also reviewed. We also discuss the current controversies that exist surrounding the management of metastatic renal cell carcinoma, including the use of risk assessment models for disease stratification and treatment selection for frontline therapy. Management of non-clear cell renal cell carcinoma subtypes is also reviewed. Future directions of research, including a discussion of ongoing clinical trials and the need for reliable biomarkers to guide treatment in kidney cancer, are also highlighted.

Avoiding "Needless" nephrectomy: What is the role of small renal mass biopsy in 2024?

Current guidelines do not mandate routine preoperative renal mass biopsy (RMB) for small renal masses (SRMs), which results in a considerable rate (18%-26%) of needless nephrectomy/partial nephrectomy for benign renal tumors. In light of this ongoing practice, a narrative review was conducted to examine the role of routine RMB for SRM. First, arguments justifying the current non-biopsy approach to SRM are critically reviewed and contested. Second, as a standalone procedure, RMB is critically assessed; RMB was found to have higher sensitivity, specificity, and an equal or lower complication rate when compared with other commonly preoperatively biopsied solid organ tumors (e.g., breast, prostate, lung, pancreas, thyroid, and liver). Based on the foregoing information, we propose a paradigm shift in SRM management, advocating for an updated policy in which partial nephrectomy or nephrectomy for SRM invariably occurs only after a preoperative biopsy confirms that a SRM is indeed malignant.

Plasma Kidney Injury Molecule-1 for Preoperative Prediction of Renal Cell Carcinoma Versus Benign Renal Masses, and Association With Clinical Outcomes

PURPOSE

Both clear cell and papillary renal cell carcinomas (RCCs) overexpress kidney injury molecule-1 (KIM-1). We investigated whether plasma KIM-1 (pKIM-1) may be a useful risk stratification tool among patients with suspicious renal masses.

METHODS

Prenephrectomy pKIM-1 was measured in two independent cohorts of patients with renal masses. Cohort 1, from the prospective K2 trial, included 162 patients found to have clear cell RCC (cases) and 162 patients with benign renal masses (controls). Cohort 2 included 247 patients with small (cT1a) renal masses from an academic biorepository, of whom 184 had RCC. We assessed the relationship between pKIM-1, surgical pathology, and clinical outcomes.

RESULTS

In Cohort 1, pKIM-1 distinguished RCC versus benign masses with area under the receiver operating curve (AUC-ROC, 0.81 [95% CI, 0.76 to 0.86]). In Cohort 2 (cT1a only), pKIM-1 distinguished RCC versus benign masses (AUC-ROC, 0.74 [95% CI, 0.67 to 0.80]) and the addition of pKIM-1 to an established nomogram for predicting malignancy improved the model AUC-ROC (0.65 [95% CI, 0.57 to 0.74] v 0.78 [95% CI, 0.72 to 0.85]). A pKIM-1 cutpoint identified using Cohort 2 demonstrated sensitivity of 92.5% and specificity of 60% for identifying RCC in Cohort 1. In long-term follow-up of RCC cases (Cohort 1), higher prenephrectomy pKIM-1 was associated with worse metastasis-free survival (multivariable MFS hazard ratio [HR] 1.29 per unit increase in log pKIM-1, 95% CI, 1.10 to 1.53) and overall survival (multivariable OS HR 1.31 per unit increase in log pKIM-1, 95% CI, 1.10 to 1.54). In long-term follow-up of Cohort 2, no metastatic events occurred, consistent with the favorable prognosis of resected cT1a RCC.

CONCLUSION

Among patients with renal masses, pKIM-1 is associated with malignant pathology, worse MFS, and risk of death. pKIM-1 may be useful for selecting patients with renal masses for intervention versus surveillance.

Stepwise algorithm using computed tomography and magnetic resonance imaging for differential diagnosis of fat-poor angiomyolipoma in small renal masses: A prospective validation study

OBJECTIVES

To validate the diagnostic accuracy of a stepwise algorithm to differentiate fat-poor angiomyolipoma (fp-AML) from renal cancer in small renal masses (SRMs).

METHODS

We prospectively enrolled 223 patients with solid renal masses <4 cm and no visible fat on unenhanced computed tomography (CT). Patients were assessed using an algorithm that utilized the dynamic CT and MRI findings in a stepwise manner. The diagnostic accuracy of the algorithm was evaluated in patients whose histology was confirmed through surgery or biopsy. The clinical course of the patients was further analyzed.

RESULTS

The algorithm classified 151 (68%)/42 (19%)/30 (13%) patients into low/intermediate/high AML probability groups, respectively. Pathological diagnosis was made for 183 patients, including 10 (5.5%) with fp-AML. Of these, 135 (74%)/36 (20%)/12 (6.6%) were classified into the low/intermediate/high AML probability groups, and each group included 1 (0.7%)/3 (8.3%)/6 (50%) fp-AMLs, respectively, leading to the area under the curve for predicting AML of 0.889. Surgery was commonly opted in the low and intermediate AML probability groups (84% and 64%, respectively) for initial management, while surveillance was selected in the high AML probability group (63%). During the 56-month follow-up, 36 (82%) of 44 patients initially surveyed, including 13 of 18 (72%), 6 of 7 (86%), and 17 of 19 (89%) in the low/intermediate/high AML probability groups, respectively, continued surveillance without any progression.

CONCLUSIONS

This study confirmed the high diagnostic accuracy for differentiating fp-AMLs. These findings may help in the management of patients with SRMs.

The evolving management of small renal masses

Small renal masses (SRMs) are a heterogeneous group of tumours with varying metastatic potential. The increasing use and improving quality of abdominal imaging have led to increasingly early diagnosis of incidental SRMs that are asymptomatic and organ confined. Despite improvements in imaging and the growing use of renal mass biopsy, diagnosis of malignancy before treatment remains challenging. Management of SRMs has shifted away from radical nephrectomy, with active surveillance and nephron-sparing surgery taking over as the primary modalities of treatment. The optimal treatment strategy for SRMs continues to evolve as factors affecting short-term and long-term outcomes in this patient cohort are elucidated through studies from prospective data registries. Evidence from rapidly evolving research in biomarkers, imaging modalities, and machine learning shows promise in improving understanding of the biology and management of this patient cohort.

[Nephron sparing in the management of localized solid renal mass]

Managing a malignant renal tumor requires, first of all, a reflection on the necessity of its treatment. It must consider the renal function, altered at the time of diagnosis in 50% of cases. The treatment method chosen depends on many factors, in particular, the predicted residual renal function, the risk of chronic kidney disease, the need for temporary or long-term dialysis, and overall long-term survival. Other factors include the size, position, and number of tumors and a hereditary tumor background. When a renal-sparing management alternative is available, total nephrectomy should no longer be performed in patients with small malignant renal masses (cT1a). This may consist of surgery (partial nephrectomy or lumpectomy), percutaneous thermo-ablation (by radiofrequency, microwave, or cryotherapy). In patients with limited life expectancy, imaging-based surveillance may be proposed to suggest treatment in case of local progression. Good coordination between urologist, radiologist, nephrologist, and sometimes radiotherapist should allow optimal management of patients with a malignant renal tumor with or without underlying renal failure.

Partial nephrectomy after a period of active surveillance: Are perioperative and pathology outcomes worsened compared to immediate surgery?

INTRODUCTION

Active surveillance (AS) is a viable strategy for managing small renal masses (SRMs) in lieu of immediate surgery, but concerns persist regarding its impact on delayed partial nephrectomy (PN) outcomes. We aimed to compare perioperative and pathological outcomes of patients initially on AS for SRMs, later undergoing PN, against those undergoing immediate PN.

MATERIALS AND METHODS

Data were extracted from a prospective institutional database (January 2018-September 2023) for patients with cT1a renal masses. Only malignancies confirmed at final pathology were included. Baseline patient and tumor characteristics and the time from AS enrollment to PN were recorded. Surgical, renal functional, and final pathology outcomes were analyzed, including histology, tumor size, pT stage, upstaging rate, and positive surgical margins. Predictors of upstaging were identified using logistic regression models.

RESULTS

Analysis included 356 patients: 307 immediate PN and 49 deferred PN after a median of 18 months in AS. Groups had comparable baseline characteristics; no significant differences emerged in surgical and postoperative outcomes. Final pathology revealed no significant disparities in tumor size, histology, positive margins, or upstaging, though pT stage distribution differed (2.4 % versus 4.3 % for pT3a, immediate versus deferred, p = 0.04). Univariable analysis identified RENAL Score (OR 1.29, 95 % C.I. 1.09-1.53, p = 0.003) and clinical tumor size (OR 1.16, 95 % C.I. 1.10-1.22, p < 0.01) as upstaging predictors, confirmed by multivariable analysis (p < 0.01).

CONCLUSION

Our comparative analysis found no worsened perioperative or adverse pathological outcomes in patients with deferred PN, supporting the safety of this approach in managing SRMs, at least as an initial option.

Adequacy of clinical guideline recommendations for patients with low-risk cancer managed with monitoring: systematic review

OBJECTIVES

The aim of this systematic review was to summarize national and international guidelines that made recommendations for monitoring patients diagnosed with low-risk cancer. It appraised the quality of guidelines and determined whether the guidelines adequately identified patients for monitoring, specified which tests to use, defined monitoring intervals, and stated triggers for further intervention. It then assessed the evidence to support each recommendation.

STUDY DESIGN AND SETTING

Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses, we searched PubMed and Turning Research into Practice databases for national and international guidelines' that were written in English and developed or updated between 2012 and 2023. Quality of individual guidelines was assessed using the AGREE II tool.

RESULTS

Across the 41 published guidelines, 48 different recommendations were identified: 15 (31%) for prostate cancer, 11 (23%) for renal cancer, 6 (12.5%) for thyroid cancer, and 10 (21%) for blood cancer. The remaining 6 (12.5%) were for brain, gastrointestinal, oral cavity, bone and pheochromocytoma and paraganglioma cancer. When combining all guidelines, 48 (100%) stated which patients qualify for monitoring, 31 (65%) specified which tests to use, 25 (52%) provided recommendations for surveillance intervals, and 23 (48%) outlined triggers to initiate intervention. Across all cancer sites, there was a strong positive trend with higher levels of evidence being associated with an increased likelihood of a recommendation being specific (P = 0.001) and the evidence for intervals was based on expert opinion or other guidance.

CONCLUSION

With the exception of prostate cancer, the evidence base for monitoring low-risk cancer is weak and consequently recommendations in clinical guidelines are inconsistent. There is a lack of direct evidence to support monitoring recommendations in the literature making guideline developers reliant on expert opinion, alternative guidelines, or indirect or nonspecific evidence.

Deep learning algorithm (YOLOv7) for automated renal mass detection on contrast-enhanced MRI: a 2D and 2.5D evaluation of results

INTRODUCTION

Accurate diagnosis and treatment of kidney tumors greatly benefit from automated solutions for detection and classification on MRI. In this study, we explore the application of a deep learning algorithm, YOLOv7, for detecting kidney tumors on contrast-enhanced MRI.

MATERIAL AND METHODS

We assessed the performance of YOLOv7 tumor detection on excretory phase MRIs in a large institutional cohort of patients with RCC. Tumors were segmented on MRI using ITK-SNAP and converted to bounding boxes. The cohort was randomly divided into ten benchmarks for training and testing the YOLOv7 algorithm. The model was evaluated using both 2-dimensional and a novel in-house developed 2.5-dimensional approach. Performance measures included F1, Positive Predictive Value (PPV), Sensitivity, F1 curve, PPV-Sensitivity curve, Intersection over Union (IoU), and mean average PPV (mAP).

RESULTS

A total of 326 patients with 1034 tumors with 7 different pathologies were analyzed across ten benchmarks. The average 2D evaluation results were as follows: Positive Predictive Value (PPV) of 0.69 ± 0.05, sensitivity of 0.39 ± 0.02, and F1 score of 0.43 ± 0.03. For the 2.5D evaluation, the average results included a PPV of 0.72 ± 0.06, sensitivity of 0.61 ± 0.06, and F1 score of 0.66 ± 0.04. The best model performance demonstrated a 2.5D PPV of 0.75, sensitivity of 0.69, and F1 score of 0.72.

CONCLUSION

Using computer vision for tumor identification is a cutting-edge and rapidly expanding subject. In this work, we showed that YOLOv7 can be utilized in the detection of kidney cancers.

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.

Diagnostic Biopsy for Small Renal Tumours: A Survey of Current European Practice

Background and objective

Renal tumour biopsy (RTB) can help in risk stratification of renal tumours with implications for management, but its utilisation varies. Our objective was to report current practice patterns, experiences, and perceptions of RTB and research gaps regarding RTB for small renal masses (SRMs).

Methods

Two web-based surveys, one for health care providers (HCPs) and one for patients, were distributed via the European Association of Urology Young Academic Urologist Renal Cancer Working Group and the European Society of Residents in Urology in January 2023.

Key findings and limitations

The HCP survey received 210 responses (response rate 51%) and the patient survey 54 responses (response rate 59%). A minority of HCPs offer RTB to >50% of patients (14%), while 48% offer it in <10% of cases. Most HCPs reported that RTB influences (61.5%) or sometimes influences (37.1%) management decisions. Patients were more likely to favour active treatment if RTB showed high-grade cancer and less likely to favour active treatment for benign histology. HCPs identified situations in which they would not favour RTB, such as cystic tumours and challenging anatomic locations. RTB availability (67%) and concerns about delays to treatment (43%) were barriers to offering RTB. Priority research gaps include a trial demonstrating that RTB leads to better clinical outcomes, and better evidence that benign/indolent tumours do not require active treatment.

Conclusions and clinical implications

Utilisation of RTB for SRMs in Europe is low, even though both HCPs and patients reported that RTB results can affect disease management. Improving timely access to RTB and generating evidence on outcomes associated with RTB use are priorities for the kidney cancer community.

Patient summary

A biopsy of a kidney mass can help patients and doctors make decisions on treatment, but our survey found that many patients in Europe are not offered this option. Better access to biopsy services is needed, as well as more research on what happens to patients after biopsy.

Safety and Diagnostic Efficacy of Image-Guided Biopsy of Small Renal Masses

INTRODUCTION

Image-guided renal mass biopsy is gaining increased diagnostic acceptance, but there are limited data concerning the safety and diagnostic yield of biopsy for small renal masses (≤4 cm). This study evaluated the safety, diagnostic yield, and management after image-guided percutaneous biopsy for small renal masses.

METHODS

A retrospective IRB-approved study was conducted on patients who underwent renal mass biopsy for histopathologic diagnosis at a single center from 2015 to 2021. Patients with a prior history of malignancy or a renal mass >4 cm were excluded. Descriptive statistics were used to summarize patient demographics, tumor size, the imaging modality used for biopsy, procedure details, complications, pathological diagnosis, and post-biopsy management. A biopsy was considered successful when the specimen was sufficient for diagnosis without need for a repeat biopsy. Complications were graded according to the SIR classification of adverse events. A chi-squared test (significance level set at p ≤ 0.05) was used to compare the success rate of biopsies in different lesion size groups.

RESULTS

A total of 167 patients met the inclusion criteria. The median age was 65 years (range: 26-87) and 51% were male. The median renal mass size was 2.6 cm (range: one-four). Ultrasound was solely employed in 60% of procedures, CT in 33%, a combination of US/CT in 6%, and MRI in one case. With on-site cytopathology, the median number of specimens obtained per procedure was four (range: one-nine). The overall complication rate was 5%. Grade A complications were seen in 4% (n = 7), consisting of perinephric hematoma (n = 6) and retroperitoneal hematoma (n = 1). There was one grade B complication (0.5%; pain) and one grade D complication (0.5%; pyelonephritis). There was no patient mortality within 30 days post-biopsy. Biopsy was successful in 88% of cases. A sub-group analysis showed a success rate of 85% in tumors <3 cm and 93% in tumors ≥3 cm (p = 0.01). Pathological diagnoses included renal cell carcinoma (65%), oncocytoma (18%), clear cell papillary renal cell tumors (9%), angiomyolipoma (4%), xanthogranulomatous pyelonephritis (1%), lymphoma (1%), high-grade papillary urothelial carcinoma (1%), and metanephric adenoma (1%), revealing benign diagnosis in 30% of cases. The most common treatment was surgery (40%), followed by percutaneous cryoablation (22%). In total, 37% of patients were managed conservatively, and one patient received chemotherapy.

CONCLUSION

This study demonstrates the safety and diagnostic efficacy of image-guided biopsy of small renal masses. The diagnostic yield was significantly higher for masses 3-4 cm in size compared to those <3 cm. The biopsy results showed a high percentage of benign diagnoses and informed treatment decisions in most patients.

Rate of benign histology after resection of suspected renal cell carcinoma: multicenter comparison between Korea and the United States

BACKGROUND

In the United States, the rate of benign histology among resected renal tumors suspected to be malignant is increasing. We evaluated the rates in the Republic of Korea and assessed the racial effect using recent multi-institutional Korean-United States data.

METHODS

We conducted a multi-institutional retrospective study of 11,529 patients (8,812 from The Republic of Korea and 2,717 from the United States) and compared the rates of benign histology between the two countries. To evaluate the racial effect, we divided the patients into Korean, Asian in the US, and Non-Asian in the US.

RESULTS

The rates of benign histology and small renal masses in Korean patients were significantly lower than that in United States patients (6.3% vs. 14.3%, p < 0.001) and (≤ 4 cm, 7.6% vs. 19.5%, p < 0.001), respectively. Women, incidentaloma, partial nephrectomy, minimally invasive surgery, and recent surgery were associated with a higher rate of benign histology than others.

CONCLUSIONS

In Korea, the rate of benign histology among resected renal tumors was significantly lower than that in the United States. This disparity could be caused by environmental or cultural differences rather than racial differences. Our findings suggest that re-evaluating current context-specific standards of care is necessary to avoid overtreatment.

Clinical Impact and Management of Incidental Renal Findings on Pre-TAVI CT Scan from the Urologist's Perspective

INTRODUCTION

The aim of the study was to investigate prevalence and impact of incidental renal masses (IRMs) accompanying increasing computed tomography (CT) work-up for symptomatic aortic valve stenosis (sAVS) of the elderly with regard to the relevance of urological consultation for overall survival (OS).

METHODS

A retrospective analysis of pre-transcatheter aortic-valve implantations (TAVIs) CT scans of patients with sAVS (N = 1,253) harboring IRM was performed for 2014-2019. According to the clinical management, groups 1 (urologic consultation) and 2 (findings ignored) were formed and analyzed in terms of OS.

RESULTS

The prevalence of IRM was 9% (119/1,253). In 19% (23/119), urological advice was sought (group 1). At baseline, group 1 showed a significantly higher rate of malignancy-specific lesions compared to 2 (p < 0.01). Other clinical parameters (e.g., age, cardiological scores, comorbidities) did not differ between groups (p > 0.05). In group 1, 4 (17%) findings were histologically confirmed, of which 3 (13%) underwent surgery. There was no significant difference in median OS at a median follow-up of 24.7 months between groups 1 and 2 with 35.7 (95% CI, 5.9; 65.4) and 47.4 months (95% CI, 33.0; 61.7), respectively (p = 0.4). In Cox regression analysis, chronic kidney disease but not urologic work-up or chronic obstructive pulmonary disease or heart failure emerged as an independent unfavorable predictor of OS (HR 2.44, 95% CI 1.37; 4.36, p = 0.003).

CONCLUSION

For the first time, a TAVI population with IRM was analyzed from the urologist's perspective. Urologic co-evaluation and work-up does not confer a significant benefit in terms of OS in this particular population.

Thermoablative Treatment of De Novo Tumor in Kidney Allograft

BACKGROUND

The overall cancer risk increases in transplant patients, including in kidney allografts. This study aimed to analyze the outcome of patients with kidney allograft malignant tumors who underwent percutaneous thermal ablation.

METHODS

We included 26 renal allograft tumors, including 7 clear-cell renal cell carcinoma (RCCs), 16 papillary RCCs, 1 clear-cell papillary RCC, and 2 tubulocystic RCCs, treated in 19 ablation sessions. Outcomes of thermal ablation therapy were assessed, including technical success, adverse events, local tumor progression, development of metastases, survival after thermal ablation, and changes in renal function.

RESULTS

Success rate was achieved in all ablation sessions (primary success rate: 96%; secondary success rate: 100%). No adverse events were observed in grades 3, 4, or 5. The median follow-up period was of 34 mo (15-69 mo). Two patients died during follow-up from a cause independent of renal cancer. The median decrease in estimated glomerular filtration rate 1 y after procedure was -4 (interquartile range, -7 to 0) mL/min/1.73 m 2 . One patient returned to dialysis within the year of the procedure.

CONCLUSIONS

Percutaneous thermal ablation shows convincing results for treating malignant renal graft tumors and should be a useful treatment option. The shorter hospitalization time, the advantage of avoiding a potentially challenging dissection of the transplant, and the excellent preservation of allograft function appear encouraging to extend this indication.

The kidney imaging surveillance scoring system (KISSS): using qualitative MRI features to predict growth rate of renal tumors in patients with von-Hippel Lindau (VHL) syndrome

OBJECTIVE

To determine the reliability of an MRI-based qualitative kidney imaging surveillance scoring system (KISSS) and assess which imaging features predict growth rate (GR) of renal tumors in patients with VHL.

MATERIALS AND METHODS

We identified 55 patients with VHL with 128 renal tumors who underwent intervention from 2015 to 2020 at the National Cancer Institute. All patients had 2 preoperative MRIs at least 3 months apart. Two fellowship-trained radiologists scored each tumor on location and MR-sequence-specific imaging parameters from the earlier MRI. Weighted kappa was used to determine the degree of agreement between radiologists for each parameter. GR was calculated as the difference in maximum tumor dimension over time (cm/year). Differences in mean growth rate (MGR) within categories of each imaging variable were assessed by ANOVA.

RESULTS

Apart from tumor margin and renal sinus, reliability was at least moderate (K > 0.40) for imaging parameters. Median initial tumor size was 2.1 cm, with average follow-up of 1.2 years. Tumor MGR was 0.42 cm/year. T2 hypointense, mixed/predominantly solid, and high restricted diffusion tumors grew faster. When comparing different combinations of these variables, the model with the lowest mean error among both radiologists utilized only solid/cystic and restricted diffusion features.

CONCLUSIONS

We demonstrate a novel MR-based scoring system (KISSS) that has good precision with minimal training and can be applied to other qualitative radiology studies. A subset of imaging variables (T2 intensity; restricted diffusion; and solid/cystic) were independently associated with growth rate in VHL renal tumors, with the combination of the latter two most optimal. Additional validation, including in sporadic RCC population, is warranted.

[Treatment of localized renal cell carcinoma]

BACKGROUND

Both partial nephrectomy (pNx) and total nephrectomy (TNx) are the mainstay of the surgical treatment of renal cell carcinoma. In smaller masses, ablative treatment as well as surveillance are possible options.

OBJECTIVE

The aim of this article is to provide a closer look at the surgical methods, active surveillance and ablative options as well as the current evidence to support their use.

MATERIAL AND METHODS

This study is based on a selective literature review regarding pNx and TNx for renal cell carcinoma using the PubMed database and the review of current European and American guidelines on surgical treatment and conservative options for renal cell carcinoma.

RESULTS

The choice of surgical method depends on the intrarenal tumor configuration as well as patient comorbidities. While pNx is used for smaller localized masses TNx is usually performed in larger more complex tumors. Both methods can be performed using a minimally invasive (laparoscopic or robotically assisted) or an open approach. In patients with severe comorbidities or a limited life expectancy, local ablative treatment options as well as surveillance strategies are suitable strategies.

Risk-stratified screening for the early detection of kidney cancer

Earlier detection and screening for kidney cancer has been identified as a key research priority, however the low prevalence of the disease in unselected populations limits the cost-effectiveness of screening. Risk-stratified screening for kidney cancer may improve early detection by targeting high-risk individuals whilst limiting harms in low-risk individuals, potentially increasing the cost-effectiveness of screening. A number of models have been identified which estimate kidney cancer risk based on both phenotypic and genetic data, and while several of the former have been shown to identify individuals at high-risk of developing kidney cancer with reasonable accuracy, current evidence does not support including a genetic component. Combined screening for lung cancer and kidney cancer has been proposed, as the two malignancies share some common risk factors. A modelling study estimated that using lung cancer risk models (currently used for risk-stratified lung cancer screening) could capture 25% of patients with kidney cancer, which is only slightly lower than using the best performing kidney cancer-specific risk models based on phenotypic data (27%-33%). Additionally, risk-stratified screening for kidney cancer has been shown to be acceptable to the public. The following review summarises existing evidence regarding risk-stratified screening for kidney cancer, highlighting the risks and benefits, as well as exploring the management of potential harms and further research needs.

Comprehensive analysis of subtypes and risk model based on complement system associated genes in ccRCC

BACKGROUND

Immune therapy is widely used in treating clear cell renal cell carcinoma (ccRCC), yet identifying patient subgroups that are expected to response remains challenging. As complement system can mediate immune effects, including the progression of tumors, a correlation between complement system and immune therapy may exist.

METHODS

Based on 11 complement system associated genes (CSAGs) identified from The Cancer Genome Atlas (TCGA), we performed unsupervised clustering and classified the tumors into two different complement system (CS) patterns. The clinical significance, tumor microenvironment (TME), functional enrichment, and immune infiltration were further analyzed. A novel scoring system named CSscore was developed based on the expression levels of the 11 CSAGs.

RESULTS

Two distinct CS patterns were identified, classified as Cluster1 and Cluster2, and Cluster1 showed poor clinical outcome. Further analysis of functional enrichment, immune cell infiltration, and genetic variation revealed that Cluster1 had high infiltration of TME immune cells, but also exhibited high immune escape. The novel prognostic model, CSscore could act as an independent prognostic factor and effectively predict patients' prognosis and distinguish the therapeutic efficacy of different immune treatment strategies. The pan-cancer analysis of the CSscore indicates its potential to be further generalized to other types of cancer.

CONCLUSIONS

Two distinct CS patterns were identified and were further analyzed in terms of infiltration of TME immune cells and immune escape, providing potential explanations for the impact on prognosis of ccRCC. Our CSscore prognostic model may offer a novel perspective in the management of ccRCC patients, and potentially other types of cancer as well.

The national utilization of nonoperative management for small renal masses over 10 years

BACKGROUND

Management of small renal masses often involves a nonoperative approach, but there is a paucity of information about the use and associated predictors of such approaches. This study aimed to determine the trends in and predictors of use of nonoperative management of small renal masses.

METHODS

Using data from the National Cancer Database for localized small renal masses (N0/M0, cT1a) diagnosed between 2010 and 2020, we conducted a cross-sectional study. Nonoperative management was defined as expectant management (active surveillance or watchful waiting) or focal ablation. Adjusted odds ratios (AORs) were calculated using multivariable logistic regression models.

RESULTS

Of the 156 734 patients included, 10.5% underwent expectant management, and 13.9% underwent focal ablation. Later year of diagnosis was associated with a higher likelihood of nonoperative management. In 2020, the odds of receiving expectant management and focal ablation were 90% (AOR = 1.90, 95% confidence interval [CI] = 1.71 to 2.11) and 44% (AOR = 1.44, 95% CI = 1.31 to 1.57) higher, respectively, than in 2010. Black patients had increased odds of expectant management (AOR = 1.47, 95% CI = 1.39 to 1.55) but decreased odds of focal ablation (AOR = 0.93, 95% CI = 0.88 to 0.99).

CONCLUSION

Over the decade, the use nonoperative management of small renal masses increased, with expectant management more frequently used than focal ablation among Black patients. Possible explanations include race-based differences in physicians' risk assessments and resource allocation. Adjusting for Black race in calculations for glomerular filtration rate could influence the differential uptake of these techniques through deflated glomerular filtration rate calculations. These findings highlight the need for research and policies to ensure equitable use of less invasive treatments in small renal masses.

MRI for the detection of small malignant renal masses: a systematic review and meta-analysis

Objective

We aimed to review the available evidence on the diagnostic performance of magnetic resonance imaging in differentiating malignant from benign small renal masses.

Methods

An electronic literature search of Web of Science, MEDLINE (Ovid and PubMed), Cochrane Library, EMBASE, and Google Scholar was performed to identify relevant articles up to 31 January 2023. We included studies that reported the diagnostic accuracy of using magnetic resonance imaging to differentiate small (≤4 cm) malignant from benign renal masses. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were calculated using the bivariate model and the hierarchical summary receiver operating characteristic model. The study quality evaluation was performed with the Quality Assessment of Diagnostic Accuracy Studies-2 tool.

Results

A total of 10 studies with 860 small renal masses (815 patients) were included in the current meta-analysis. The pooled sensitivity and specificity of the studies for the detection of malignant masses were 0.85 (95% CI 0.79-0.90) and 0.83 (95% CI 0.67-0.92), respectively.

Conclusions

MRI had a moderate diagnostic performance in differentiating small malignant renal masses from benign ones. Substantial heterogeneity was observed between studies for both sensitivity and specificity.

Utility of multiparametric renal CT for differentiation of low-grade from high-grade cT1a clear cell renal cell carcinoma

OBJECTIVE

To determine if CT can differentiate low-grade from high-grade clear cell renal cell carcinoma (ccRCC) in cT1a solid ccRCC.

METHODS AND MATERIALS

This retrospective cross-sectional study evaluated 78 < 4 cm solid (>25% enhancing) ccRCC in 78 patients with renal CT within 12 months of surgery between January 2016 and December 2019. Two radiologists (R1/R2), blinded to pathology, independently recorded mass:size, calcification, attenuation and heterogeneity (5-point Likert scale) and recorded a 5-point ccRCC CT Score. Multivariate logistic regression (LR) was performed.

RESULTS

There were 64.1% (50/78) low-grade (5/50 Grade 1 and 45/50 Grade 2) and 35.9% (28/78) high-grade (27/28 Grade 3 and 1/28 Grade 4) tumors.Unenhanced CT attenuation was higher (35.9±10.3 R1 and 34.9±10.7 R2 high-grade vs 29.7±10.2 R1 and 29.5±9.8 R2 low-grade, p=0.01-0.02), absolute corticomedullary phase attenuation ratio (CMphase-ratio; 0.67±0.16 R1 and 0.66±0.16 R2 vs 0.93±0.83 R1 and 0.80±0.33 R2, p=0.04-0.05) and 3-tiered stratification of CMphase-ratio (p=0.02) lower in high-grade tumors.A two-variable LR-model including unenhanced CT attenuation and CM.phase-ratio achieved area under the receiver operator characteristic curve of: 73% (95% confidence intervals 59-86%) and 72% (59-84%) for R1 and R2.ccRCC CT score differed by ccRCC grade (p<0.01 R1, R2) with high-grade tumors occurring most commonly in moderately enhancing ccRCC score 4 (46.4% [13/28] R1 and 54% [15/28]).

CONCLUSION

Among cT1a ccRCC, high-grade tumors have higher unenhanced CT attenuation and are less avidly enhancing.

ADVANCES IN KNOWLEDGE

High-grade ccRCC have higher attenuation (possibly due to less microscopic fat) and lower corticomedullary phase enhancement compared to low-grade tumors. This may result in categorization of high-grade tumors in lower ccRCC diagnostic algorithm categories.

Morbidity of elective surgery for localized renal masses among elderly patients: A contemporary multicenter study

BACKGROUND

The aging population and the incidence of renal cell carcinoma (RCC) are increasing worldwide. Over 25% of newly diagnosed LRM (localized renal masses) occur in patients over the eighth decade of life. The decision-making and treatment approach to LRM in this population represents a clinical dilemma due to inherited decreased functional reserve and competing mortality risks. Current literature reports conflicting evidence regarding age as a risk factor for worst surgical outcomes. As such, we aimed to evaluate the contemporary morbidity of elective surgery for LRM among elderly patients, focusing on intraoperative and postoperative complications.

METHODS

After Ethical Committee approval, we queried our prospectively maintained databases to identify patients with preoperative eGFR ≥60 ml/min/1.73 m [(David and Bloom, 2022) 22 and a normal contralateral kidney who underwent partial or radical nephrectomy (PN or RN) for a single cT1-T2N0M0 LRM between 1/2015-12/2021 at four high-volume European Academic Institutions. Patients were categorized by age groups: <50 yrs (young) vs. 50-75 (middle-aged) yrs vs.> 75 yrs (elderly). Postoperative complications were recorded according to Clavien-Dindo (CD) classification. The primary objectives were the proportion of patients experiencing intraoperative (IOC), any grade (AGC), and high-grade postoperative complications (HGC), defined as CD grade 3-5.

RESULTS

Overall, 2469/3076 (80.2%) patients met the inclusion criteria. Of these, 363 (14.7%) were young, 1682 (68.1%) were middle-aged, and 424 (17.2%) were elderly. Compared to middle-aged and young patients, elderly patients had a higher median Charlson Comorbidity Index (6 vs. 4 vs. 0, p < 0.01) and a higher proportion of cT1 renal mass (87.6% vs. 93.0% vs. 93.6%, p < 0.01). No differences among the study groups were found regarding surgical approach (open vs. minimally-invasive) and type of surgery (PN vs. RN). We found that older patients experienced similar IOC (4.5% vs. 4.2% vs. 3.3%, p = 0.7) and AGC (23.1% vs. 20.0% vs. 21.5%, p = 0.4) compared to middle-aged and young patients, respectively. Similarly, there were no significant differences in HGC between the study cohorts (0.7% vs. 1.4% vs. 1.7%, p = 0.8). At multivariable analysis, open approach and PN significantly predicted the occurrence of AGCs, while only the open surgical approach was associated with the occurrence of HGCs.

CONCLUSION

In kidney cancer tertiary referral centers, the risk of IOC and postoperative HGC after PN or RN for localized renal masses (LRM) is low, despite a non-negligible risk of AGC, especially in elderly patients. Further efforts should focus on identifying multidisciplinary strategies to select patients most likely to benefit from surgery among elderly candidates with LRMs and decrease the morbidity of surgery in this specific setting.

Building a Roadmap for Surveillance of Renal Masses Using a Modified Delphi Method to Help Achieve Consensus

OBJECTIVE

To establish a consensus for initial evaluation and follow-up of patients on active surveillance (AS) for T1 renal masses (T1RM).

METHODS

A modified Delphi method was used to gather information about AS of T1RM, with a focus on patient selection, timing/type of imaging modality, and triggers for intervention. A consensus panel of Michigan Urological Surgery Improvement Collaborative-affiliated urologists who routinely manage renal masses was formed. Areas of consensus (defined >80% agreement) about T1RM AS were established iteratively via 3 rounds of online questionnaires.

RESULTS

Twenty-six Michigan Urological Surgery Improvement Collaborative urologists formed the panel. Consensus was achieved for 321/587 scenarios (54.7%) administered through 124 questions. Life expectancy, age, comorbidity, and renal function were most important for patient selection, with life expectancy ranking first. All tumors <3 cm and all patients with life expectancy <1 year were considered appropriate for AS. Appropriateness also increased with elevated perioperative risk, increasing tumor complexity, and/or declining renal function. Consensus was for multiphasic axial imaging initially (contrast CT for GFR >60 or MRI for GFR >30) with first repeat imaging at 3-6 months and subsequent imaging timing determined by tumor size. Consensus was for chest imaging for tumors >3 cm initially and >5 cm at follow up. Renal biopsy was not felt to be a requirement for entering AS, but useful in several scenarios. Consensus indicated rapid tumor growth as an appropriate trigger for intervention.

CONCLUSION

Our consensus panel was able to achieve areas of consensus to help define a clinically useful and specific roadmap for AS of T1RM and areas for further discussion where consensus was not achieved.

Surgical Management of Localized Disease and Small Renal Masses

The incidence of renal cancer has increased over the past several decades, but mortality has declined. This is thought to be related in part to earlier detection of renal masses which portend excellent 5-year survival rates. Management of small renal masses and localized disease include both nonsurgical and surgical options. The choice of intervention is ultimately based on comprehensive evaluation and shared decision-making. This article provides a comprehensive review of the current surgical management options for localized renal cancer.

A Matched Analysis of Active Surveillance Versus Nephrectomy for T1a Small Renal Masses

While patients with a small renal mass (SRM) on active surveillance (AS) experience excellent metastasis-free survival (MFS) and cancer-specific survival (CSS), differences in overall survival (OS) observed may be explained by selection of older/comorbid patients for AS. Few studies have evaluated AS versus primary intervention in clinically balanced groups. We identified patients aged 55-75 yr with an SRM (≤4 cm, T1a) in our institutional database (2000-2020). Patients from AS and nephrectomy subgroups were matched exactly for age, sex, Eastern Cooperative Oncology Group (ECOG) performance status, biopsy status, and histology. The primary outcomes were OS and an event-free survival (EFS) composite that included OS, CSS, MFS, progression, or systemic therapy, which we tested in Cox proportional-hazards models. We identified 377 patients (205 AS, 172 nephrectomy). The cohort was balanced after matching (n = 110; mean age 64 yr, 77% male, and 75% ECOG score 0). In each arm, 47% were biopsied (predominantly clear-cell histology). The predicted 5-yr OS was 96% for the nephrectomy group and 95% for the AS group (hazard ratio for nephrectomy vs AS [HR] 0.83, 95% confidence interval [CI] 0.13-5.32; p = 0.8), with corresponding 5-yr EFS rates of 93% and 96% (HR 1.88, 95% CI 0.35-10.15; p = 0.5). Among SRM cases well matched for age and overall health status, we observed higher 5-yr OS and EFS rates for AS than previously reported; the rates were not significantly different from those after nephrectomy. The matched characteristics of our population are similar to those for treatment arms in contemporary cohorts and the results support the safety of AS in younger, healthier patients. PATIENT SUMMARY: While it has been shown that active surveillance for small kidney tumors is safe in older and more frail patients, its safety in younger, healthier patients has not been confirmed. We compared outcomes for patients aged 55-75 yr who were managed with surgery or active surveillance, and were similar in age and overall health. The probability of death after 5 years was low overall and not significantly different between the groups, suggesting that active surveillance is safe in routine clinical practice.

Guidelines for surveillance of patients with von Hippel-Lindau disease: Consensus statement of the International VHL Surveillance Guidelines Consortium and VHL Alliance

Von Hippel‐Lindau disease is a rare inherited cancer‐predisposition syndrome. The authors report the updated recommendations for the multiorgan surveillance protocols.

The 5-item frailty index predicts 30-day morbidity and mortality in radical nephrectomy patients: A propensity matched analysis

PURPOSE

To assess the ability of the 5-item frailty index (5-IFi) score to predict 30-day morbidity and mortality post-radical nephrectomy (RN).

METHODS

ACS-NSQIP database was used to select patients who underwent RN from 2011 to 2020. 5-IFi score was calculated by assigning a point for each of the following comorbidities: chronic obstructive pulmonary disease or pneumonia, congestive heart failure, dependent functional status, hypertension, and diabetes. Patients were divided into 3 frailty groups 0, 1, and ≥2. Patient demographics, medical comorbidities, prolonged length of stay, and prolonged operative time were compared between different groups; mortality and morbidity using the Clavien-Dindo classification (CVD). Multivariable logistic regression models and propensity score matching were performed as a sensitivity analysis to control for possible confounders.

RESULTS

Cohort consisted of 36,682 patients whereby 5-IFi class 0, 1, and ≥2 included 11,564 (31.5%), 16,571 (45.2%), and 8,547 (25.3%) patients respectively. A multivariable analysis and propensity score matching revealed that patients with 5-IFi classes 1 and ≥ 2 were more likely to have a prolonged length of stay (OR = 1.11, 1.3, respectively) and to mortality (OR = 1.85 for frailty class ≥2); in addition to CVD class 1 & 2 (OR = 1.51, OR = 1.13, respectively), and CVD ≥ 4 (OR = 1.41, 1.86, respectively) as compared to 5-IFi class 0 (P < 0.001).

CONCLUSION

The 5-IFi score was found to be an independent predictor of prolonged length of stay, morbidity, and mortality after RN. This tool can play a major role in preoperative risk assessment and patient counseling based on individualized risks.

Exploring the Characteristics of Circulating Tumor DNA in Pt1a Clear Cell Renal Cell Carcinoma: A Pilot Study

Circulating tumor DNA (ctDNA) is a promising biomarker for clear cell renal cell carcinoma (ccRCC); however, its characteristics in small renal masses of ccRCC remain unclear. In this pilot study, we explored the characteristics of ctDNA in pT1a ccRCC. Plasma samples were collected preoperatively from 53 patients with pT1a ccRCC. The ctDNA of pT1a ccRCC was profiled using next-generation sequencing and compared with that of higher-stage ccRCC. The association of ctDNA in pT1a ccRCC with clinicopathological features was investigated. The positive relationship of mutations between ctDNA and matched tissues was evaluated. In pT1a ccRCC, the ctDNA detection rate, cell-free DNA concentration, and median variant allele frequency were 20.8%, 5.8 ng/mL, and 0.38%, respectively, which were significantly lower than those in metastatic ccRCC. The ctDNA gene proportions in pT1a samples differed from those in metastatic ccRCC samples. The relationships between ctDNA and tumor size, tumor grade, and patient age were not elucidated. The positive concordance between ctDNA and matched tissues was poor for pT1a ccRCC. Strategies are needed to increase sensitivity while eliminating noise caused by clonal hematopoiesis to increase the clinical utility of ctDNA analysis in small renal masses of ccRCC.

The Changing Role of Renal Mass Biopsy

The incidence and prevalence of small renal masses (SRMs) continues to rise and with increased detection comes increases in surgical management, although the probability of an SRM being benign is upward of 30%. An extirpative treatment first diagnose-later strategy persists and clinical tools for risk stratification such as renal mass biopsy remain severely underutilized. The overtreatment of SRMs has multiple detrimental effects including surgical complications, psychosocial stress, financial loss, and reduced renal function leading to downstream effects such as the need for dialysis and cardiovascular disease.

Diagnostic Accuracy of MRI for Solid Renal Masses: A Systematic Review and Meta-analysis

BACKGROUND

Biparametric (bp)-MRI and multiparametric (mp)-MRI may improve the diagnostic accuracy of renal mass histology.

PURPOSE

To evaluate the available evidence on the diagnostic accuracy of bp-MRI and mp-MRI for solid renal masses in differentiating malignant from benign, aggressive from indolent, and clear cell renal cell carcinoma (ccRCC) from other histology.

STUDY TYPE

Systematic review.

POPULATION

MEDLINE, EMBASE, and CENTRAL up to January 11, 2022 were searched.

FIELD STRENGTH/SEQUENCE

1.5 or 3 Tesla.

ASSESSMENT

Eligible studies evaluated the accuracy of MRI (with at least two sequences: T2, T1, dynamic contrast and diffusion-weighted imaging) for diagnosis of solid renal masses in adult patients, using histology as reference standard. Risk of bias and applicability were assessed using QUADAS-2.

STATISTICAL TESTS

Meta-analysis using a bivariate logitnormal random effects model.

RESULTS

We included 10 studies (1239 masses from approximately 1200 patients). The risk of bias was high in three studies, unclear in five studies and low in two studies. The diagnostic accuracy of malignant (vs. benign) masses was assessed in five studies (64% [179/281] malignant). The summary estimate of sensitivity was 95% (95% confidence interval [CI]: 77%-99%), and specificity was 63% (95% CI: 46%-77%). No study assessed aggressive (vs. indolent) masses. The diagnostic accuracy of ccRCC (vs. other subtypes) was evaluated in six studies (47% [455/971] ccRCC): the summary estimate of sensitivity was 85% (95% CI: 77%-90%) and specificity was 77% (95% CI: 73%-81%).

DATA CONCLUSION

Our study reveals deficits in the available evidence on MRI for diagnosis of renal mass histology. The number of studies was limited, at unclear/high risk of bias, with heterogeneous definitions of solid masses, imaging techniques, diagnostic criteria, and outcome measures.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

A novel nephrectomy-specific respiratory failure index using the ACS-NSQIP dataset

PURPOSE

Post-operative pulmonary failure is a major complication of nephrectomy that may lead to severe morbidity and mortality. Hence, we aimed to derive a nephrectomy-specific post-operative respiratory failure index.

METHODS

Our cohort was derived from The American College of Surgeons-National Surgical Quality Improvement Program database between 2005 and 2019. The outcome of interest was post-operative respiratory failure (PRF) defined as any incidence of unplanned intubation post-operatively or requiring mechanical ventilation post-operatively for a period > 48 h. A multivariable logistic regression model was constructed, and model calibration and performance were assessed using a ROC analysis and the Hosmer-Lemeshow test. Finally, we derived the nephrectomy-specific respiratory failure (NSRF) index and compared it to Gupta's index.

RESULTS

Seventy-nine thousand five hundred and twenty-three patients underwent nephrectomy between the years 2005 and 2019 of which nine hundred and sixty-two patients developed PRF. The final NSRF model encompassed ten variables: age, smoking status, American society of anesthesiology class, abnormal creatinine (≥ 1.5 mg/dL), anemia (< 36%), functional health status, chronic obstructive pulmonary disease, surgical approach, emergency case, and obesity (≥ 40 kg/m²). The NSRF ROC analysis provided C-statistic = 0.78, calibration R² = 0.99, and proper goodness of fit. In comparison, the C-statistics of Gupta's index was found to be 0.71 (p value < 0.001).

CONCLUSION

The NSRF is a procedure tailored index for predicting post-operative respiratory failure. It is a valuable tool in the pre-operative evaluation setting that can help identify high-risk patients who will require additional respiratory evaluation and preparation for their surgery.

Evaluation of Growth Rates for Small Renal Masses in Elderly Patients Undergoing Active Surveillance

Background

As the adoption of active surveillance (AS) for small renal masses (SRMs) grows, the number of elderly patients enrolled for a prolonged period of time will increase. However, our understanding of comparative growth rates (GRs) in aging patients with SRMs remains poor.

Objective

To examine whether particular age cutoffs are associated with an increased GR for patients undergoing AS for SRMs.

Design setting and participants

We identified all patients with SRMs enrolled in the multi-institutional, prospective Delayed Intervention and Surveillance for Small Renal Masses (DISSRM) registry since 2009 who elected for AS.

Outcome measurements and statistical analysis

Two definitions of GR were examined: GR from the initial image (GRi) and GR from the prior image (GRp). Image measurements were dichotomized based on patient age at the time of imaging. Multiple age cutoffs were examined: 65, 70, 75, and 80 yr. Mixed-effect linear regression examined the associations between age and GR, with controlling to account for multiple measurements from the same individual.

Results and limitations

We examined 2542 measurements from 571 patients. The median age at enrollment was 70.9 yr (interquartile range [IQR] 63.2-77.4) with a median tumor diameter of 1.8 cm (IQR 1.4-2.5). As a continuous variable, age was not associated with GRi (-0.0001 cm/yr, 95% confidence interval [CI] -0.007 to 0.007, p = 0.97) or GRp (0.008 cm/yr, 95% CI -0.004 to 0.020, p = 0.17) after adjustment. The only age thresholds associated with an increased GR were 65 yr for GRi and 70 yr for GRp. Limitations include the one-dimensional nature of the measurements used.

Conclusions

Increased age for patients on AS for SRMs is not associated with increased GRs.

Patient summary

We examined whether patients undergoing active surveillance (AS) exhibited accelerated growth of their small renal masses (SRMs) after a certain age. No demonstrable change was seen, suggesting that AS is a safe and durable management option for aging patients with SRMs.

Diagnostic performance of the "drooping" sign in CT diagnosis of exophytic renal angiomyolipoma

OBJECTIVE

To evaluate the prevalence of angular interface and the "drooping" sign in exophytic renal angiomyolipomas (AMLs) and the diagnostic performance in differentiating exophytic lipid-poor AMLs from other solid renal masses.

METHODS

This IRB-approved, two-center study included 185 patients with 188 exophytic solid renal masses < 4 cm with histopathology and pre-operative CT within 30 days of surgical resection or biopsy. Images were reviewed for the presence of angular interface and the "drooping" sign qualitatively by three readers blinded to the final diagnosis, with majority rules applied. Both features were assessed quantitatively by cohort creators (who are not readers) independently. Free-marginal kappa was used to assess inter-reader agreement and agreement between two methods assessing each feature. Fisher's exact test, Mann-Whitney test, and multivariable logistic regression with two-tailed p < 0.05 were used to determine statistical significance. Diagnostic performance was assessed.

RESULTS

Ninety-four patients had 96 AMLs, and 91 patients had 92 non-AMLs. Seventy-four (77%) of AMLs were lipid-poor based on quantitative assessment on CT. The presence of angular interface and the "drooping" sign by both qualitative and quantitative assessment were statistically significantly associated with AMLs (39% (qualitative) and 45% (quantitative) vs 15% (qualitative) and 13% (quantitative), and 48% (qualitative) and 43% (quantitative) vs 4% (qualitative) and 1% (quantitative), respectively, all p < 0.001) in univariable analysis. In multivariable analysis, only the "drooping" sign in either qualitative or quantitative assessment was a statistically significant predictor of AMLs (both p < 0.001). Inter-reader agreement for the "drooping" sign was moderate (k = 0.55) and for angular interface was fair (k = 0.33). Agreement between the two methods of assessing the "drooping" sign was substantial (k = 0.84) and of assessing the angular interface was moderate (k = 0.59). The "drooping" sign both qualitatively and quantitatively, alone or in combination of angular interface, had very high specificity (96-100%) and positive predictive value (PPV) (89-100%), moderate negative predictive value (62-68%), but limited sensitivity (23-49%) for lipid-poor AMLs.

CONCLUSION

The "drooping" sign by both qualitative and quantitative assessment is highly specific for lipid-rich and lipid-poor AMLs. This feature alone or in combination with angular interface can aid in CT diagnosis of lipid-poor AMLs with very high specificity and PPV.

Factors associated with pathological tumor stage and T3a upstage in clinical T1-2 renal cell carcinoma

INTRODUCTION

Considering the oncological outcomes, understanding the preoperative factors associated with and predicting advanced stage and T3a upstage will help in risk assessment and selection of the right treatment.

MATERIAL AND METHOD

Patients with postoperative pathology of Renal Cell Carcinoma (RCC) and stage T1-2 N0M0 were included in the study. Demographic and pathological characteristics of the patients, Neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and De Ritis- the ratio of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were recorded. Patients were classified according to T stage (T1-2 vs T3-4) and T3a upstage (T3a upstaged vs non-T3a upstaged).

RESULTS

A total of 289 patients participated in the study when inclusion and exclusion criteria were applied. No difference was found between the groups in terms of age, gender, body mass index, laterality, ABO blood group, Rh positivity and comorbidities. According to multivariate analysis, PLR, AST/ALT, Fuhrman grade, open radical nephrectomy (RN) and Clear Cell pathological subtype were found to be significant-independent factors in predicting advanced stage (T3-4) and T3a upstage (P<0.05).

CONCLUSION

It was found that higher PLR and AST/ALT ratios were associated with more advanced stage and postoperative T3a upstage in RCC patients. In addition, these patients more frequently had open RN and had higher Fuhrman grades, while the clear cell subtype was less common.

Sunitinib resistance in renal cell carcinoma: From molecular mechanisms to predictive biomarkers

Currently, renal cell carcinoma (RCC) is the most prevalent type of kidney cancer. Targeted therapy has replaced radiation therapy and chemotherapy as the main treatment option for RCC due to the lack of significant efficacy with these conventional therapeutic regimens. Sunitinib, a drug used to treat gastrointestinal tumors and renal cell carcinoma, inhibits the tyrosine kinase activity of a number of receptor tyrosine kinases, including vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), c-Kit, rearranged during transfection (RET) and fms-related receptor tyrosine kinase 3 (Flt3). Although sunitinib has been shown to be efficacious in the treatment of patients with advanced RCC, a significant number of patients have primary resistance to sunitinib or acquired drug resistance within the 6-15 months of therapy. Thus, in order to develop more efficacious and long-lasting treatment strategies for patients with advanced RCC, it will be crucial to ascertain how to overcome sunitinib resistance that is produced by various drug resistance mechanisms. In this review, we discuss: 1) molecular mechanisms of sunitinib resistance; 2) strategies to overcome sunitinib resistance and 3) potential predictive biomarkers of sunitinib resistance.

Survival benefit stratification of partial nephrectomy versus non-surgical treatment in elderly patients with T1a renal cell carcinoma

BACKGROUND

Renal cell carcinoma (RCC) of stage T1a has been proven to be of low-grade malignancy and mostly affects elderly individuals with relatively limited life expectancy. However, research on the survival benefit of surgery relative to non-surgical treatment (NST) is limited. The aim of the study was to investigate the survival difference between partial nephrectomy (PN) and NST and to establish a benefit stratification model for elderly patients (≥70 years) diagnosed with T1a RCC.

PATIENTS AND METHODS

Patients diagnosed with non-metastatic T1a RCC who received PN or NST were identified from the SEER database during 2004-2015. Before survival analysis, propensity score matching (PSM) was performed. Overall survival (OS) was estimated by the Kaplan-Meier method, and subgroup analyses were used to identify favorable factors of PN. Independent factors of survival were recognized by multivariate Cox regression analysis.

RESULTS

Patients diagnosed with non-metastatic T1a RCC who received PN or NST were identified from the SEER database during 2004-2015. Before survival analysis, propensity score matching (PSM) was performed. Overall survival (OS) was estimated by the Kaplan-Meier method, and subgroup analyses were used to identify favorable factors of PN. Independent factors of survival were recognized by multivariate Cox regression analysis.

CONCLUSIONS

Our findings suggest that the survival benefit of PN could be stratified based on the clinical characteristics in patients with stage T1a RCC aged 70 years or older, which may help physicians and patients optimize clinical decisions.

Diagnostic Accuracy of 99mTc-Sestamibi SPECT/CT for Characterization of Solid Renal Masses

Our objective was to assess the diagnostic accuracy of ^99mTc-sestamibi SPECT/CT for characterizing solid renal masses. Methods: Imaging and clinical records of patients who underwent ^99mTc-sestamibi SPECT/CT for clinical work-up of their solid renal masses from September 2018 to October 2021 were retrospectively reviewed. Histopathology formed the reference standard, and the diagnoses were categorized as malignant/concerning (renal cell carcinomas [RCCs] other than chromophobe histology) and benign/nonconcerning (oncocytic tumors including chromophobe RCC, other benign diagnoses) to calculate the sensitivity and specificity of ^99mTc-sestamibi SPECT/CT and contrast-enhanced CT (ceCT). The clinical reads of the SPECT/CT images were used for visual classification of the lesions. Additionally, the SPECT images were manually segmented to obtain the maximum and mean counts of the lesion and adjacent renal cortex and maximum and mean lesion Hounsfield units. Results: ^99mTc-sestamibi SPECT/CT was performed on 42 patients with 62 renal masses. A histopathologic diagnosis was available for 27 patients (18 male, 9 female) with 36 solid renal masses. ceCT findings were available for 20 of these patients. The most commonly identified single histologic type was clear cell RCC (13/36; 36.1%). Oncocytic tumors were the most common group of nonconcerning lesions (15/36), with oncocytoma as the predominant histologic type (n = 6). The sensitivity and specificity of SPECT/CT for diagnosing a nonconcerning lesion were 66.7% and 89.5%, respectively, compared with 10% and 75%, respectively, for ceCT. The lesion-to-kidney ratios for maximum and mean counts and maximum lesion Hounsfield units showed significant differences between the 2 groups (P < 0.05). The lesion-to-kidney mean count ratio at a cutoff of 0.46 showed a sensitivity and specificity of 87.5% and 86.67%, respectively, for detecting nonconcerning lesions, which was significantly higher than that of ceCT. Conclusion: The current literature on the utility of ^99mTc-sestamibi SPECT/CT for characterization of solid renal masses is limited. We offer additional evidence of the incremental value of ^99mTc-sestamibi SPECT/CT over ceCT for differentiating malignant or aggressive renal tumors from benign or indolent ones, thereby potentially avoiding overtreatment and its associated complications. Quantitative assessment can further increase the diagnostic accuracy of SPECT/CT and may be used in conjunction with visual interpretation.

A Renewal of the TNM Staging System for Patients with Renal Cancer To Comply with Current Decision-making: Proposal from the European Association of Urology Guidelines Panel

Over the past decade, only minor changes have been introduced in the TNM staging system for renal cancer. Conversely, many milestones and modifications in management of the disease have been achieved, especially for patients with locally advanced and metastatic cancers. The European Association of Urology guidelines panel proposes a new TNM classification scheme for staging of renal cell carcinoma to reflect these breakthrough clinical improvements.

Impact of Time-To-Surgery on the Prognosis of Patients with T1 Renal Cell Carcinoma: Implications for the COVID-19 Pandemic

Background: During the COVID-19 pandemic, elective surgery has to undergo longer wait times, including nephrectomy for T1 renal cell carcinoma (RCC). This study aimed to investigate the time-to-surgery (TTS) of Chinese T1 RCC patients and its influencing factors, and to illustrate the impact of TTS on the prognosis of T1 RCC. Methods: We retrospectively enrolled 762 Chinese patients with pathological T1 RCC that underwent nephrectomy. To discover the impact of TTS on survival outcomes, we explored the possible delay intervals by week using the Kaplan-Meier method and Log-rank test. Cox proportional hazard models with inverse probability-treatment weighting (IPTW) were used to assess the association between TTS and disease-free survival (DFS) and overall survival (OS). Results: The median TTS of T1 RCC patients was 15 days. The Charlson comorbidity index, the Preoperative Aspects and Dimensions Used for an Anatomical (PADUA) score, and the maximal tumor diameter on presentation were independent influencing factors for TTS. The cut-off point of TTS was selected as 5 weeks according to the Log-rank analysis. For T1a RCC, patients with TTS > 5 weeks had similar DFS (HR = 2.39; 95% CI, 0.82−6.94; p = 0.109) and OS (HR = 1.28; 95% CI, 0.23−7.16; p = 0.779) compared to patients with TTS ≤ 5 weeks. For T1b RCC, patients with TTS > 5 weeks had shorter DFS (HR = 2.90; 95% CI = 1.46−5.75; p = 0.002) and OS (HR = 2.49, 95% CI = 1.09−5.70; p = 0.030) than patients with TTS ≤ 5 weeks. Conclusions: Prolonged TTS had no impact on the prognosis of T1a RCC while surgery delayed for over 5 weeks may lead to worse survival in T1b RCC.

Understanding Hospital-Level Patterns of Nonoperative Management for Low-risk Thyroid and Kidney Cancer

IMPORTANCE

There is a growing trend toward conservative management for certain low-risk cancers. Hospital and health-system factors may play a role in determining how these patients are managed.

OBJECTIVE

To explore the contribution of hospitals on patients' odds of nonoperative management for low-risk cancer.

DESIGN, SETTING, AND PARTICIPANTS

In this cross-sectional study, individuals with low-risk papillary thyroid cancer and solitary kidney masses were identified, and those receiving nonoperative management vs surgery were compared. Patients with low-risk thyroid cancer and kidney cancer from 2015 to 2017 eligible for nonoperative management according to National Comprehensive Cancer Network guidelines within the National Cancer Database were included. Data were analyzed from October 2021 to March 2022.

MAIN OUTCOMES AND MEASURES

For each facility, the proportion of these patients who received operative and nonoperative management was calculated. A mixed-effects logistic regression model with a hospital-level random effects term was used to calculate factors associated with nonoperative management. Between-hospital variability was assessed using ranked caterpillar plots.

RESULTS

There were 19 570 individuals with low-risk thyroid cancer (15 344 women [78.4%]; mean [SD] age, 51.74 [95% CI, 51.39-52.08] years) and 41 403 with kidney cancer (25 253 men [61.0%]; mean [SD] age, 61.93 [95% CI, 61.70-62.17] years). In the group with low-risk thyroid cancer, 2.1% (419 patients) received nonoperative management, and in the group with kidney cancer, 9.5% (3928 patients) received nonoperative management. This varied between hospitals from 1.1% (95% CI, 1.0%-1.1%) in the bottom decile to 10.3% (95% CI, 8.0%-12.4%) in the top decile for low-risk thyroid cancer, and from 4.3% (95% CI, 4.1%-4.4%) in the bottom decile to 24.6% (95% CI, 22.7%-26.5%) in the top decile for small kidney masses. For both cancers, age was associated with increased odds of nonoperative treatment. The hospital-level odds of nonoperative management of thyroid and kidney cancer using unadjusted probabilities (observed proportions) were minimally correlated (Spearman ρ = .33; P < .001).

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that although health systems factors may be associated with the tendency to pursue nonoperative management, hospital-level factors may differ when comparing unrelated cancers.

Molecular subtypes based on cuproptosis regulators and immune infiltration in kidney renal clear cell carcinoma

Copper toxicity involves the destruction of mitochondrial metabolic enzymes, triggering an unusual mechanism of cell death called cuproptosis, which proposes a novel approach using copper toxicity to treat cancer. However, the biological function of cuproptosis has not been fully elucidated in kidney renal clear cell carcinoma (KIRC). Using the expression profile of 13 cuproptosis regulators, we first identified two molecular subtypes related to cuproptosis defined as “hot tumor” and “cold tumor”, having different levels of biological function, clinical prognosis, and immune cell infiltration. We obtained three gene clusters using the differentially expressed genes between the two cuproptosis-related subtypes, which were associated with different molecular activities and clinical characteristics. Next, we developed and validated a cuproptosis prognostic model that included two genes (FDX1 and DBT). The calculated risk score could divide patients into high- and low-risk groups. The high-risk group had a poorer prognosis, lower level of immune infiltration, higher frequency of gene alterations, and greater levels of FDX1 methylation and limited DBT methylation. The risk score was also an independent predictive factor for overall survival in KIRC. The established nomogram calculating the risk score achieved a high predictive ability for the prognosis of individual patients (area under the curve: 0.860). We then identified small molecular inhibitors as potential treatments and analyzed the sensitivity to chemotherapy of the signature genes. Tumor immune dysfunction and exclusion (TIDE) showed that the high-risk group had a higher level of TIDE, exclusion and dysfunction that was lower than the low-risk group, while the microsatellite instability of the high-risk group was significantly lower. The results of two independent immunotherapy datasets indicated that cuproptosis regulators could influence the response and efficacy of immunotherapy in KIRC. Our study provides new insights for individualized and comprehensive therapy of KIRC.

IQGAP3 in clear cell renal cell carcinoma contributes to drug resistance and genome stability

Background

Clear cell renal clear cell carcinoma (ccRCC) is resistant to most chemotherapeutic drugs and the molecular mechanisms have not been fully revealed. Genomic instability and the abnormal activation of bypass DNA repair pathway is the potential cause of tumor resistance to radiotherapy and chemotherapy. IQ-motif GTPase activating protein 3 (IQGAP3) regulates cell migration and intercellular adhesion. This study aims to analysis the effects of IQGAP3 expression on cell survival, genome stability and clinical prognosis in ccRCC.

Methods

Multiple bioinformatics analysis based on TCGA database and IHC analysis on clinical specimens were included. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot (WB) were used to determine protein expression level. MTT assay and 3D spheroid cell growth assay were used to assess cell proliferation and drug resistance in RNAi transfected ccRCC cells. Cell invasion capacity was evaluated by transwell assay. The influence of IQGAP3 on genome instability was revealed by micronuclei number and γ H2AX recruitment test.

Results

The highly expressed IQGAP3 in multiple subtypes of renal cell carcinoma has a clear prognostic value. Deletion of IQGAP3 inhibits cell growth in 3D Matrigel. IQGAP3 depletion lso increases accumulated DNA damage, and improves cell sensitivity to ionizing radiation and chemotherapeutic drugs. Therefore, targeting DNA damage repair function of IQGAP3 in tumorigenesis can provide ideas for the development of new targets for early diagnosis.