The penetration of renal mass biopsy in daily practice: a survey among urologists

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.

The Utility of Renal Mass Biopsy in Shared Decision-Making for Renal Mass Treatment

OBJECTIVE

To evaluate the utility of renal mass biopsy (RMB) in shared decision-making for renal mass treatment. Underutilization of RMB for patients with renal masses is due in part to physicians believing that results have limited clinical utility.

MATERIALS AND METHODS

This was a prospective study of all patients referred for RMB from October 2019 to October 2021. Patients and physicians completed pre- and post-RMB questionnaires. Questionnaires assessed both parties' perceived utility of RMB and the impact of biopsy results on treatment preference using Likert scales.

RESULTS

We enrolled 22 patients with a mean age of 66years (SD 14.5) and mean renal tumor size 3.1 cm (SD 1.4). Five were lost to follow-up (three pre-RMB, two post-RMB). Pre-RMB, 100% of patients believed that a biopsy would help them choose a treatment and 45% were unsure of their treatment preferences. After RMB, 92% perceived their biopsy results as useful and only 9% were unsure of treatment preference. Overall, 100% of patients were glad they had a biopsy. Results led patients and physicians to change their treatment preference in 57% and 40% of cases, respectively. Patients and physicians disagreed about treatment in 81% of cases prior to biopsy, but in only 25% of cases after biopsy.

CONCLUSION

Discordance between patient and physician treatment preference for renal masses is higher in the absence of RMB data. Select patients are willing to undergo RMB and RMB data can increase patient confidence and comfort in a shared decision-making approach for renal mass treatment.

Artificial Intelligence in Renal Cell Carcinoma Histopathology: Current Applications and Future Perspectives

Renal cell carcinoma (RCC) is characterized by its diverse histopathological features, which pose possible challenges to accurate diagnosis and prognosis. A comprehensive literature review was conducted to explore recent advancements in the field of artificial intelligence (AI) in RCC pathology. The aim of this paper is to assess whether these advancements hold promise in improving the precision, efficiency, and objectivity of histopathological analysis for RCC, while also reducing costs and interobserver variability and potentially alleviating the labor and time burden experienced by pathologists. The reviewed AI-powered approaches demonstrate effective identification and classification abilities regarding several histopathological features associated with RCC, facilitating accurate diagnosis, grading, and prognosis prediction and enabling precise and reliable assessments. Nevertheless, implementing AI in renal cell carcinoma generates challenges concerning standardization, generalizability, benchmarking performance, and integration of data into clinical workflows. Developing methodologies that enable pathologists to interpret AI decisions accurately is imperative. Moreover, establishing more robust and standardized validation workflows is crucial to instill confidence in AI-powered systems' outcomes. These efforts are vital for advancing current state-of-the-art practices and enhancing patient care in the future.

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.

Comprehensive optimization of urinary exfoliated tumor cells tests in bladder cancer with a promising microfluidic platform

BACKGROUND

Enrichment of urinary exfoliated tumor cells (UETCs) is a noninvasive way of bladder cancer diagnosis, but the lack of specific capture and identification of tumor cells from the urine remains a limitation that impedes the development of liquid biopsy.

METHODS

The CytoBot^® 2000, a novel circulating cell isolation and enrichment platform, was used for UETCs isolation after comprehensive optimization. The commercial cell lines of bladder cancer were used in spiking assay for cell recovery test. The flow cytometry and immunofluorescent staining assays were performed for expression validation of capture target and identification markers. The performance of optimized platform was validated by 159 clinical samples and analyzed using receiver operator characteristic curve.

RESULTS

The chip that had a pore diameter of 15*20 μm could reduce the background residues while maintaining a higher cell recovery rate. We found that the cell capture ability of chip significantly improved after anti-EpCam antibody encapsulation, but not with T4L6FM1. In identification system optimization, the spiking assay and validation of clinical sample showed that the performance of CK20 and DBC-1 were better that pan-CK in tumor cell identification, in addition, the staining quality is more legible with CK20.

CONCLUSION

The optimized capture chip is more specific for UETCs isolation. CK20 and DBC-1 are both sensitive biomarkers of UETCs in bladder cancer diagnosis. The performance of this optimized platform is excellent in clinical test that improves the accuracy of urine cell testing and provides a new alternative for the clinical application of BLCA liquid biopsy assessment.

Renal Tumor Biopsy: Rationale to Avoid Surgery in Small Renal Masses

PURPOSE OF REVIEW

The use of renal tumor biopsy (RTB) for small renal masses (SRMs) in daily practice, although safe and accurate, is unusual. Considering the large number of benign tumors in patients with renal masses < 4 cm, some patients with benign tumors are directly referred for surgery instead. This study aimed to report the diagnostic rates of RTB, determine the concordance with surgical pathology, and assess the number of procedures that could have been avoided. We retrospectively studied 255 patients who underwent RTB at our institution in 2010-2019. Of them, 73 were excluded from the analysis (exclusion criteria: > 4 cm, cystic lesion, missing data). The remaining 182 with undetermined SRMs ≤ 4 cm underwent RTB under computed tomography guidance.

RECENT FINDINGS

Biopsies were diagnostic in 154/182 (84.6%) cases. Of the non-diagnostic biopsies, 11 were diagnostic when repeated. When RTB was performed of all undetermined SRMs, active treatment (surgery or cryotherapy) was avoided in 50/182 patients (27.5%) because of a benign diagnosis, while 9/182 patients (4.9%) underwent surveillance after a shared multidisciplinary decision. The overall diagnostic rate was 90.6%. All adverse events (approximately 4%) were Clavien-Dindo grade I and did not require active treatment. RTB histology results and nuclear grade were highly concordant with the final pathology (96% and 86.6%, respectively). On univariate logistic regression analysis, male sex was the only contributing factor of diagnostic biopsy. RTB of SRMs should be performed more frequently as part of a multidisciplinary decision-making process since it avoided unnecessary surgical treatment in 1 of 3 patients in our institution.

Active Surveillance of Small Renal Masses: A Systematic Review

BACKGROUND: Our goal is to review current literature regarding active surveillance (AS) of small renal masses (SRMs) and identify trends in survival outcomes, factors that predict the need for further intervention, and quality of life (QOL). METHODS: We performed a comprehensive literature search in PubMed and EMBASE and identified 194 articles. A narrative summary was performed in lieu of a meta-analysis due to the heterogeneity of selected studies. RESULTS: Seventeen articles were chosen to be featured in this review. Growth rate (GR) was not an accurate predictor of malignancy, although it was the characteristic most commonly used to trigger delayed intervention (DI). The mean 5-year overall survival (OS) of all studies was 73.6% ±1.7% for AS groups. The combined cancer specific survival (CSS) for AS is 97.1% ±0.6%, compared to 98.6% ±0.4% for the primary intervention (PI) groups, (p = 0.038). CONCLUSIONS: Short and intermediate-term data demonstrate that AS with the option for DI is a management approach whose efficacy (in terms of CSS) approaches that of PI at 5 years, is cost effective, and prevents overtreatment, especially in patients with significant comorbidities.

Feasibility and Outcomes of Renal Mass Biopsy for Anatomically Complex Renal Tumors

OBJECTIVE

To compare the feasibility and outcomes of renal mass biopsies (RMB) of anatomically complex vs non-complex renal masses.

METHODS

Our institutional renal tumor database was queried for patients who underwent RMB between 2005 and 2019 and with available nephrometry score. Complex masses were: (1) small (<2 cm), (2) entirely endophytic (nephrometry E=3), (3) hilar (h) or (4) partially endophytic (E=2) and anterior. Demographic and pathologic data were compared. Biopsies were deemed adequate if they resulted in a diagnosis. Concordance with surgical pathology was assessed. These were both presented using proportions. Factors associated with biopsy outcomes were identified using multivariable logistic regression. RMB sensitivity and specificity were calculated using contingency methods.

RESULTS

A total of 306 RBMs were included, 179 complex and 127 non-complex. A total of 199 (65%) had an extirpative procedure. Complex lesions were less likely to have an adequate biopsy (89% vs 96%, P = .03), and to be concordant with final surgical pathology from an oncologic standpoint (89% vs 97%, P = .03). There was no significant difference in concordance of histology (76% vs 86%, P = .10) or grade (48 vs 51%, P = .66). On multivariable analyses, only male gender was associated with biopsy adequacy (OR 3.31, 95% CI 1.28-8.55, P = .01). Our overall sensitivity was 93%, specificity 93%, and accuracy 93%. There were no significant differences over time in biopsy outcomes during the study period.

CONCLUSION

RMB of complex lesions is associated with excellent diagnostic yield, albeit lower than non-complex lesions. RMB should not be deferred in cases of anatomically complex lesions where additional data could improve clinical decision-making.

[Dignity of Small Renal Masses: Implications for Diagnostics and Therapy]

Dignity of Small Renal Masses: Implications for Diagnostics and Therapy Abstract. The ubiquitous availability of radiological imaging has increased the diagnosis of renal incidentalomas with a diameter ≤4 cm. If malignancy is suspected, these are often treated surgically without prior biopsy. However, several studies demonstrate a relevant proportion of benign tumors, equating to a degree of overtreatment. There are no Swiss data available. Renal tumors resected in our center between 2006 and 2014 (n = 404) were retrospectively examined for size on cross-sectional imaging and their respective histology, identifying 221 (54.7 %) small renal masses with a diameter ≤4 cm. Of these, 62 (28 %) were benign and three (1.4 %) were of unclear or low malignant potential. Among the remaining 156 malignancies, 116 (74.4 %) were classified as prognostically favorable, allowing for active surveillance, if the patient's clinical context allows.

Utilization of renal mass biopsy in patients with localized renal cell carcinoma: A population-based study utilizing the National Cancer Database

OBJECTIVE

To evaluate trends and factors predicting use of renal mass biopsy (RMB) for localized Renal Cell Carcinoma in the United States (US) in the context of current guidelines recommendations.

METHODS

We queried the National Cancer Database for cT1-cT3N0M0 Renal Cell Carcinoma diagnosed between 2004 and 2015. Temporal trends of RMB were characterized based on tumor size, treatment (partial nephrectomy [PN], radical nephrectomy [RN], ablation, and no treatment), age and Charlson Comorbidity Index with slopes compared using analysis of variance. Multivariable analysis was used to determine factors associated with use of RMB.

RESULTS

Of 338,252 patients analyzed, 11.9% (40,276) underwent RMB. Use of RMB increased throughout the study period from 1,586 (7.6%) in 2004 to 5,629 (16.2%) in 2015 (P < 0.001). Use of RMB increased greatest for ablation (27 to 63%, P < 0.001) and tumors 2-4 cm (9 to 20%, P < 0.001). Multivariable analysis showed year of diagnosis (OR = 1.06; P < 0.001), higher education (OR = 1.09; P < 0.001) and insured status (OR = 1.23; P < 0.001) were associated with increased RMB. Compared to tumors ≤2 cm, tumors 2.1-4 cm (OR = 1.36; P=<0.001), 4.1-7 cm (OR = 1.18; P <0.001) and >7 cm (OR = 1.05; P = 0.03) were associated with higher rates of RMB. Compared to RN, PN was not associated with increased RMB (OR = 1.00; P = 0.92), while ablation (OR = 10.90; P < 0.001) and no surgical treatment (OR = 4.83; P < 0.001) were.

CONCLUSION

RMB utilization increased overall, with largest increase associated with ablation. Nonetheless, only two-thirds of patients underwent RMB with ablation, suggesting persistent underutilization. Rates of RMB for tumors ≤2 cm and in those undergoing no treatment increased less, suggesting less utilization for surveillance. However, rates for tumors >2-4 cm increased more, suggesting selective utilization of RMB to guide decision-making and risk stratification in small renal masses.

Contemporary trends in percutaneous renal mass biopsy utilization in the United States

INTRODUCTION

Patients with a renal mass traditionally proceed directly to surgery without a preoperative tissue diagnosis confirming malignancy. Many surgically treated renal masses represent benign tumors or indolent malignancies on final pathology. This has led to a growing body of literature supporting an expanded role for percutaneous renal mass biopsy (RMB). This study aims to characterize national trends in RMB utilization.

METHODS

Patients undergoing renal biopsy during a 12-year period (2006-2017) in the Premier Hospital Database were captured using International Classification of Diseases, Ninth Revision and Tenth Revision codes. We restricted our analysis to patients with a concurrent diagnosis of a renal mass. We determined utilization rate, subsequent interventions within 90 days of biopsy, predictors of RMB, and 30-day RMB complication rates. We applied sampling weights and adjusted for hospital clustering to achieve a nationally representative analysis.

RESULTS

Among 115,511 patients who met the inclusion criteria, the annual number of RMB rose from 7,196 in 2006 to 11,528 in 2017; during this period, more than 3 times as many patients proceeded directly to surgery without a prior RMB. After RMB, 85,848 (74.32%) patients were not treated within 90 days. Of those treated, thermal ablation was more common than surgery (17,269 vs. 12,394). Trend analysis showed that patients with metastatic disease represented a decreasing proportion of patients receiving RMB (27.0%-21.8%; P < 0.001). Compared to patients who proceeded directly to surgery, RMB was more commonly performed in patients in the highest age group (80 years and older, 15.9% vs. 9.2%), unmarried (50% vs. 45.9%), with more medical comorbidities (Charlson comorbidity index ≥4, 30.9% vs. 17.4%), or with metastatic disease (24.5% vs. 10.4%). Multivariable regression analysis determined the primary predictor of RMB was the presence of metastatic disease. Hematuria was the most common complication present in 5.18% of patients followed by pneumothorax in 1.75%. All other complications were rare (<0.4%).

CONCLUSION

Although there has been progressive adoption of RMB for the management of renal masses in the United States, utilization remains relatively limited and differentially employed across the population based on both clinical and nonclinical patient factors. More research is needed to understand which factors are considered when determining whether to utilize RMB in the evaluation of a renal mass.

The role of renal mass biopsy in the management of small renal masses – patterns of use and surgeon opinion

Aims:

Renal mass biopsy (RMB) is advocated to improve management of small renal masses, however there is concern about its clinical utility. This study aimed to elicit opinions about the role of RMB in small renal mass management from surgeons managing renal cell carcinomas (RCC), and examine the frequency of pre-treatment biopsy in those with RCC.

Methods:

All surgeons in two Australian states (Queensland: n = 59 and Victoria: n = 108) who performed nephrectomies for RCC in 2012/2013 were sent questionnaires to ascertain views about RMB. Response rates were 54% for Queensland surgeons and 38% for Victorian surgeons. We used medical records data from RCC patients to determine RMB frequency.

Results:

Most Queensland (81%) and Victorian (59%) surgeons indicated they rarely requested RMB; however 34% of Victorians reported often requesting RMB, compared with no Queensland surgeons. This was consistent with medical records data: 17.6% of Victorian patients with T1a tumours received RMB versus 6.7% of Queensland patients ( p < 0.001). Surgeons’ principal concerns regarding RMB related to sampling reliability (90%) and/or histopathological interpretation (76%).

Conclusions:

Most surgeons report infrequent use of RMB for small renal masses, however we observed practice variation. The principal reasons for infrequent use were concerns about sampling reliability and histopathological interpretation, which may be valid in regions with less access to interventional radiologists and uropathologists. Further evidence is required to define patient groups for whom biopsy results will alter management.

Level of evidence:

Not applicable for this multicentre audit.

Searching for prognostic biomarkers for small renal masses in the urinary proteome

Renal cell carcinoma (RCC) is frequently diagnosed incidentally as an early-stage small renal mass (SRM; pT1a, ≤4 cm). Overtreatment of patients with benign or clinically indolent SRMs is increasingly common and has resulted in a recent shift in treatment recommendations. There are currently no available biomarkers that can accurately predict clinical behavior. Therefore, we set out to identify early biomarkers of RCC progression. We employed a quantitative label-free liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) proteomics approach and targeted parallel-reaction monitoring to identify and validate early, noninvasive urinary biomarkers for RCC-SRMs. In total, we evaluated 115 urine samples, including 33 renal oncocytoma (≤4 cm) cases, 30 progressive and 26 nonprogressive clear cell RCC (ccRCC)-SRM cases, in addition to 26 healthy controls. We identified six proteins, which displayed significantly elevated expression in clear cell RCC-SRMs (ccRCC-SRMs) relative to healthy controls. Proteins C12ORF49 and EHD4 showed significantly elevated expression in ccRCC-SRMs compared to renal oncocytoma (≤4 cm). Additionally, proteins EPS8L2, CHMP2A, PDCD6IP, CNDP2 and CEACAM1 displayed significantly elevated expression in progressive relative to nonprogressive ccRCC-SRMs. A two-protein signature (EPS8L2 and CCT6A) showed significant discriminatory ability (areas under the curve: 0.81, 95% CI: 0.70-0.93) in distinguishing progressive from nonprogressive ccRCC-SRMs. Patients (Stage I-IV) with EPS8L2 and CCT6A mRNA alterations showed significantly shorter overall survival (p = 1.407 × 10^-6 ) compared to patients with no alterations. Our in-depth proteomic analysis identified novel biomarkers for early-stage RCC-SRMs. Pretreatment characterization of urinary proteins may provide insight into early RCC progression and could potentially help assign patients to appropriate management strategies.

Utilization and Operative Influence of Renal Mass Biopsy in the Small Renal Mass: Analysis from the Clinical Research Office of the Endourological Society Small Renal Mass registry

Introduction and Objective: Definitive inclusion of renal mass biopsy (RMB) in small renal mass (SRM) diagnostic algorithm remains controversial. We assessed incidence and accuracy of RMB in SRMs in the CROES Renal Mass registry and the influence of preoperative RMB on perioperative complications after SRM nephron-sparing surgery (NSS). Materials and Methods: "ad hoc" description of incidence of preoperative RMB and characteristics of SRM cases with and without RMB. Accuracy of RMB was calculated in the SRM subcohort that received extirpative treatment and complication rate after NSS compared to between the two groups. Continuous variables were compared using t-test; categorical variables were compared using the chi-square test. K-statistics was used to analyze agreement between the biopsy histology and surgical pathology. Logistic regression was used to assess the association between RMB and NSS complications. All tests were two sided, and p-values <0.05 were considered statistically significant. Results: The rate of preoperative RMB in SRMs was 11.6% (175/1597) in Europe and the United States. RMB patients were more likely to have hypertension (p < 0.04), be on dialysis (p < 0.024), or smokers (p = 0.005), with multiple/bilateral tumors (0.008 and 0.010) and previous other malignancy (p = 0.021). They underwent radical nephrectomy more frequently than non-RMB group (p = 0.034). RMB was nondiagnostic in 16 cases (9%). Accuracy of RMB in distinguishing malignant from benign was 89.5%. Agreement between biopsy and final surgical pathology was 93% for malignant vs benign tumors (kappa = 0.655). Upstaging to pT3a occurred more frequently in the RMB group (12.6% vs 6.25% [p = 0.022]). Complication rate in renal mass-NSS subcohort was 15.8%, not statistically different between RMB and non-RMB groups. On logistic regression analysis, RMB was not associated with increased risk of postoperative complication after NSS (OR: 0.9, 95% CI: 0.43-1.89). Conclusion: The practice of RMB in SRM is still scarce despite high accuracy and concordance with final pathology. RMB does not seem to increase complication rate after NSS.

Renal mass biopsy: an oncological conundrum

PURPOSE OF REVIEW

We evaluate the reasons that the majority of urologists infrequently biopsy a T1a small renal mass (SRM).

RECENT FINDINGS

The majority of urologists report that a renal mass biopsy will not change their management in patients with a SRM given concerns of safety and efficacy of the biopsy. However, when comparing the safety and efficacy of SRM biopsy with neoplasms in all other major organ systems (all of which require biopsy prior to treatment), renal mass biopsy results are favorable. In addition to being safe and effective, renal mass biopsy should be more cost-effective for the healthcare system. Finally, in properly selected patients, renal mass biopsy can be performed in the urologist's office, thereby further decreasing cost.

SUMMARY

Renal mass biopsy is an essential clinical tool that needs to be incorporated into the decision-making process among patients with a T1a SRM. A biopsy-driven, tissue-specific diagnosis of SRMes should become the standard of care in urology to bring us to parity with standard practice to management of lesions identified in every other organ system.

Current Management of Small Renal Masses, Including Patient Selection, Renal Tumor Biopsy, Active Surveillance, and Thermal Ablation

Renal cancer represents 2% to 3% of all cancers, and its incidence is rising. The increased use of ultrasonography and cross-sectional imaging has resulted in the clinical dilemma of incidentally detected small renal masses (SRMs). SRMs represent a heterogeneous group of tumors that span the full spectrum of metastatic potential, including benign, indolent, and more aggressive tumors. Currently, no composite model or biomarker exists that accurately predicts the diagnosis of kidney cancer before treatment selection, and the use of renal mass biopsy remains controversial. The management of SRMs has changed dramatically over the last two decades as our understanding of tumor biology and competing risks of mortality in this population has improved. In this review, we critically assess published consensus guidelines and recent literature on the diagnosis and management of SRMs, with a focus on patient treatment selection and use of renal mass biopsy, active surveillance, and thermal ablation. Finally, we highlight important opportunities for leveraging recent research discoveries to identify patients with SRMs at high risk for renal cell carcinoma-related mortality and minimize overtreatment and patient morbidity.

Pretreatment Diagnosis of the Small Renal Mass: Status of Renal Biopsy in the United States of America

INTRODUCTION

We surveyed United States of America-based urologists to characterize practice patterns and indications to perform a renal mass biopsy for small renal masses.

MATERIALS AND METHODS

Members of the American Urological Association who practice in the United States were invited to participate in a 11-question web-based survey that was distributed via SurveyMonkey^® from December 2016 to January 2017.

RESULTS

There were 1131 respondents. The respondents equally represented all regions of the United States; the majority were in private practice. Overall, 32% of American urologists would "never" perform a biopsy of a renal mass ≤4 cm. Those who saw fewer than five small renal masses per year were more likely to "never" perform a renal biopsy on either a renal mass ≤4 cm or a renal mass 2-3 cm compared with those who saw more than five small renal masses per year (p < 0.001). Urologists who practiced at an academic hospital were more likely to perform a renal biopsy on both a renal mass ≤4 cm and a renal mass 2-3 cm compared with private practice and government-based urologists (p < 0.001 and p = 0.008 respectively). The primary reason for not performing a biopsy, cited by 68% of responding urologists, was that the results of a biopsy "would not change their management of the renal mass." Respondents independently performed only 2% of biopsies; however, almost half stated that they would be interested in learning office-based ultrasound-guided biopsy of a small renal mass.

CONCLUSIONS

Among members of the American Urological Association, biopsy of a small renal mass remains an underutilized diagnostic procedure, especially in light of 6000 unnecessary surgeries annually; nonuniversity-based urologists and those who see <5 renal mass cases each year infrequently perform a biopsy. Currently, interventional radiologists perform almost all small renal mass biopsies.

Update on the types and usage of liquid biopsies in the clinical setting: a systematic review

Background

This systematic review aimed to gather evidence from research on the current state of liquid biopsy in medical practice, specifically focusing on mutation detection and monitoring.

Methods

A systematic search was performed via Medline.

Results

The results of this investigation indicate that liquid biopsy plays a critical role in the detection and management of tumors. This technique gives healthcare providers the ability to gather critical and reliable information that may potentially shape the diagnosis, treatment, and prognosis of a variety of cancers in the near future. This study further reveals that liquid biopsy has several potential shortcomings that may limit its application and use in the healthcare setting. Nevertheless, liquid biopsy remains a valuable tool that is gradually becoming a part of routine healthcare practice in oncology departments and hospitals worldwide.

Conclusions

The evidence described herein reveals the potential relevance of liquid biopsy as an important prognostic, diagnostic, and theranostic tool. This non-invasive procedure enables healthcare practitioners to detect and monitor genomic alterations and will likely replace tumor tissue biopsy as the standard method for detecting and monitoring mutations in the future. The information obtained herein can enable physicians to make informed decisions regarding current treatment options; however, liquid biopsy has not yet been incorporated into routine clinical diagnostics for cancer patients.

Identifying the use and barriers to the adoption of renal tumour biopsy in the management of small renal masses

INTRODUCTION

Renal tumour biopsies (RTBs) can provide the histology of small renal masses (SRMs) prior to treatment decision-making. However, many urologists are reluctant to use RTB as a standard of care. This study characterizes the current use of RTB in the management of SRMs and identifies barriers to a more widespread adoption.

METHODS

A web-based survey was sent to members of the Canadian and Quebec Urological Associations who had registered email address (n=767) in June 2016. The survey examined physicians' practice patterns, RTB use, and potential barriers to RTB. Chi-squared tests were used to assess for differences between respondents.

RESULTS

The response rate was 29% (n=223), of which 188 respondents were eligible. A minority of respondents (12%) perform RTB in >75% of cases, while 53% never perform or perform RTB in <25% of cases. Respondents with urological oncology fellowship training were more likely to request a biopsy than their colleagues without such training. The most frequent management-related reason for not using routine RTB was a belief that biopsy won't alter management, while the most frequent pathology-related reason was the risk of obtaining a false-negative or a non-diagnostic biopsy.

CONCLUSIONS

Adoption of RTBs remains low in Canada. Concerns about the accuracy of RTB and its ability to change clinical practice are the largest barriers to adoption. A knowledge translation strategy is needed to address these concerns. Future studies are also required in order to define where RTB is most valuable and how to best to implement it.

Accuracy and safety of ultrasound-guided percutaneous needle core biopsy of renal masses: A single center experience in China

Our aim is to determine the sufficiency, accuracy, and safety of ultrasound-guided percutaneous needle core biopsy of renal masses in Chinese patients.Patients who had undergone ultrasound-guided needle core renal mass biopsy from June 2012 to June 2016 at West China Hospital, China were retrospectively reviewed. The information obtained included demographics, mass-related parameters, biopsy indications, technique, complications, pathologic results, and follow-up. Concordance of surgical resection pathology and follow-up data were assessed.Renal mass biopsies were performed in 106 patients. Thirty-nine (36.8%) were asymptomatic. The male/female ratio was 60/46, with a median age of 49.5 years. Median mass size was 8.1 cm (range 1.8-20). Biopsy was performed through a 16-gauge needle, with median cores of 2 taken (range 1-5). Only one significant biopsy-related complication (hemorrhage requiring transfusion) was encountered. An adequate tissue sample was obtained in 97.2% (103/106) of biopsies. Eighty-seven biopsies (82.1%) showed malignant neoplasms, 16 (15.1%) yielded benignity, and 3 (2.8%) were nondiagnostic. After biopsy, 46 patients (43.4%) underwent surgery. Compared with the subsequent mass resection pathology, the biopsy diagnoses were identical in 43 cases. The accuracy rate of biopsy distinguishing malignant from benign lesions was 99.1%, and the rate for determining tumor histological type (excluding the nondiagnostic biopsies) was 95.1%. The sensitivity and specificity in detecting malignancy were 98.9% and 100%, respectively.In several situations, there is still a role for biopsy before intervention. Percutaneous needle core biopsy under ultrasonography guidance is highly accurate and safe, and can determine the proper management of undefinable masses.

Diagnostic Needle Biopsies in Renal Masses: Patient and Physician Perspectives

BACKGROUND

The utility of renal mass biopsies (RMB) in the diagnosis of kidney tumors remains debatable.

OBJECTIVE

To assess patient and urologist preferences regarding the utilization of RMB.

DESIGN, SETTING, AND PARTICIPANTS

Seventy-three patients diagnosed with renal tumors and 59 board-certified urologists were asked to participate in an interview-based study.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Using the standard gamble method we determined the minimal accepted accuracy at which RMB would be favored as part of the diagnostic process. Clinical and demographic data with potential to affect participants' preferences were analyzed.

RESULTS AND LIMITATIONS

At the time of the study interview, 56 patients (77%) were referred for kidney surgery and 17 (23%) opted for surveillance. Overall, 59% of the patients accepted some level of inaccuracy (1-20%), whereas 27% refuted a biopsy. Anxiety associated with the possibility of missing cancer was the primary determinant (82%) for declining RMB among patients referred for surgery, while fear of complications was the primary reason (58%) among those undergoing surveillance. Having an academic degree was associated with a lower accuracy threshold (p=0.03). Of the 59 participating urologists, 39% were reluctant to recommend RMB, primarily because of its inexorable nondiagnostic rate.

CONCLUSIONS

Most patients and urologists would favor RMB to facilitate their definitive treatment decision. Diagnostic accuracy of 95% was acceptable by the majority of study participants. The utility of RMB as part of the diagnostic algorithm for renal tumors should be discussed with patients, emphasizing its potential benefits and limitations.

PATIENT SUMMARY

Although needle biopsy seems to be an effective tool to differentiate benign from malignant kidney lesions, it is not commonly used. Our study shows that most patients would opt for a biopsy before definitive treatment decision despite its imperfect accuracy. Hence, the option of undergoing renal biopsy should be discussed with all patients diagnosed with small renal tumors.

Liquid biopsy: a step forward towards precision medicine in urologic malignancies

There is a growing trend towards exploring the use of a minimally invasive "liquid biopsy" to identify biomarkers in a number of cancers, including urologic malignancies. Multiple aspects can be assessed in circulating cell-free DNA, including cell-free DNA levels, integrity, methylation and mutations. Other prospective liquid biopsy markers include circulating tumor cells, circulating RNAs (miRNA, lncRNAs and mRNAs), cell-free proteins, peptides and exosomes have also emerged as non-invasive cancer biomarkers. These circulating molecules can be detected in various biological fluids, including blood, urine, saliva and seminal plasma. Liquid biopsies hold great promise for personalized medicine due to their ability to provide multiple non-invasive global snapshots of the primary and metastatic tumors. Molecular profiling of circulating molecules has been a stepping-stone to the successful introduction of several non-invasive multi-marker tests into the clinic. In this review, we provide an overview of the current state of cell-free DNA-based kidney, prostate and bladder cancer biomarker research and discuss the potential utility other circulating molecules. We will also discuss the challenges and limitations facing non-invasive cancer biomarker discovery and the benefits of this growing area of translational research.

Magnetic Resonance Imaging as a Biomarker for Renal Cell Carcinoma

As the most common neoplasm arising from the kidney, renal cell carcinoma (RCC) continues to have a significant impact on global health. Conventional cross-sectional imaging has always served an important role in the staging of RCC. However, with recent advances in imaging techniques and postprocessing analysis, magnetic resonance imaging (MRI) now has the capability to function as a diagnostic, therapeutic, and prognostic biomarker for RCC. For this narrative literature review, a PubMed search was conducted to collect the most relevant and impactful studies from our perspectives as urologic oncologists, radiologists, and computational imaging specialists. We seek to cover advanced MR imaging and image analysis techniques that may improve the management of patients with small renal mass or metastatic renal cell carcinoma.

Renal Tumor Biopsy for Small Renal Masses: A Single-center 13-year Experience

BACKGROUND

Renal tumor biopsy (RTB) for the characterization of small renal masses (SRMs) has not been widely adopted despite reported safety and accuracy. Without pretreatment biopsy, patients with benign tumors are frequently overtreated.

OBJECTIVE

To assess the diagnostic rate of RTBs, to determine their concordance with surgical pathology, and to assess their impact on management.

DESIGN, SETTING, AND PARTICIPANTS

This is a single-institution retrospective study of 529 patients with biopsied solid SRMs ≤4 cm in diameter. RTBs were performed to aid in clinical management.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Diagnostic and concordance rates were presented using proportions. Factors that contributed to a diagnostic biopsy were identified using a multivariable logistic regression.

RESULTS AND LIMITATIONS

The first biopsy was diagnostic in 90% (n=476) of cases. Of the nondiagnostic biopsies, 24 patients underwent a second biopsy of which 83% were diagnostic. When both were combined, RTBs yielded an overall diagnostic rate of 94%. Following RTB, treatment could have been avoided in at least 26% of cases because the lesion was benign. Tumor size and exophytic location were significantly associated with biopsy outcome. RTB histology and nuclear grade were highly concordant with final pathology (93% and 94%, respectively). Adverse events were low (8.5%) and were all self-limited with the exception of one. Although excellent concordance between RTB and final pathology was observed, only a subset of patients underwent surgery following biopsy. Thus it is possible that some patients were misdiagnosed.

CONCLUSIONS

RTB of SRMs provided a high rate of diagnostic accuracy, and more than a quarter were benign. Routine RTB for SRMs informs treatment decisions and diminishes unnecessary intervention. Our results support its systematic use and suggest that a change in clinical paradigm should be considered.

PATIENT SUMMARY

Renal tumor biopsy (RTB) for pretreatment identification of the pathology of small renal masses (SRMs) is safe and reliable and decreases unnecessary treatment. Routine RTB should be considered in all patients with an indeterminate SRM for which treatment is being considered.

Renal biopsy with 16G needle: a safety study

INTRODUCTION AND OBJECTIVE

The development of percutaneous renal biopsy as a routinary diagnostic procedure for renal masses is topic of discussion for the last few years. However, this technique has been associated with some complications, although infrequent, and morbidity. Our objective is to carry out a descriptive study about complications and outcomes of orthotopic kidney biopsies with 16 G needle.

MATERIAL AND METHODS

A retrospective review of 180 orthotopic ultrasound-guided renal biopsies performed in our service among January 2008 to May 2010 was carried out. The procedure was developed using an automated biopsy gun (16G needle). Multiple clinical variables, early post-procedure complications and its management were collected. Complication rates as well as the relationship between risk factors and occurrence of complications were studied.

RESULTS

Mean age was 55.8 years. The average number of biopsy cylinders per intervention was 2.49. The overall complication rate was 5.6%. An interventionist attitude derived from complication of the procedure was necessary in only 3 patients (1.67%). No surgical interventions were required and no death as consequence of procedure was registered. No relationship between hypertension (P=.09) previous anticoagulation (P=.099) or previous antiaggregation (P=.603) and complications were demonstrated. In 2.8% of biopsies the material obtained was insufficient for diagnosing.

CONCLUSIONS

Percutaneous ultrasound-guided renal biopsy with 16G needle is a safe technique with high diagnostic performance.

BAP1 immunohistochemistry predicts outcomes in a multi-institutional cohort with clear cell renal cell carcinoma

PURPOSE

Mutations in the tumor suppressor gene BAP1 occur in approximately 15% of clear cell renal cell carcinoma cases. Sequencing efforts demonstrated worse outcomes in patients with BAP1 mutated clear cell renal cell carcinoma. We investigated the clinicopathological significance and oncologic outcomes of BAP1 loss using a previously validated immunohistochemical assay.

MATERIALS AND METHODS

Immunohistochemistry for BAP1 was performed on tissue microarray sections from 559 nonmetastatic clear cell renal cell carcinoma cases treated with nephrectomy at multiple institutions. The association of BAP1 expression with clinicopathological parameters was analyzed using the Wilcoxon rank sum and Cochran-Mantel-Haenszel tests. Survival was assessed by Cox regression analysis, which also identified independent predictors of time dependent outcomes.

RESULTS

At a median followup of 50 months (range 0 to 183) 86 of 483 patients (17.8%) experienced recurrence and 121 of 559 (21.6%) had died. BAP1 was negative in 82 of 559 tumors (14.7%). BAP1 loss was associated with adverse clinicopathological variables, including high Fuhrman grade (p <0.0001), advanced pT stage (p = 0.0021), sarcomatoid dedifferentiation (p = 0.0001) and necrosis (p <0.0001). Cox regression revealed that patients with BAP1 negative tumors had significantly worse disease-free survival (HR 2.9, 95% CI 1.8-4.7, p <0.0001) and overall survival (HR 2.0, 95% CI 1.3-3.1, p = 0.0010) than patients with BAP1 positive tumors.

CONCLUSIONS

Immunohistochemistry for BAP1 serves as a powerful marker to predict poor oncologic outcomes and adverse clinicopathological features in patients with nonmetastatic clear cell renal cell carcinoma. BAP1 assessment using immunohistochemistry on needle biopsy may benefit preoperative risk stratification and guide treatment planning in the future.

A review of contemporary data on surgically resected renal masses--benign or malignant?

OBJECTIVE

To clearly define the proportions of benign vs malignant histologic findings in resected renal masses through an in-depth review of the contemporary medical data to assist in preoperative risk assessment.

MATERIALS AND METHODS

PubMed and select oncology congresses were searched for publications that identify the histologic classification of resected renal masses in a representative sample from the contemporary data: [search] incidence AND (renal cell carcinoma AND benign); incidence AND (renal tumor AND benign); percentage AND (renal cell carcinoma AND benign); limit 2003-2011.

RESULTS

We identified 26 representative studies meeting the inclusion criteria and incorporating 27,272 patients. The frequency of benign tumors ranged from 7% to 33%, with most studies within a few percentage points of the mean (14.5% ± 5.2%, median 13.9%). Clear cell renal cell carcinoma occurred in 46% to 83% of patients, with a mean of 68.3% (median 61.3; SD = 11.9%). An inverse relationship between tumor size and benign pathologic features was identified in 14 of 19 (74%) studies that examined an association between tumor size and pathologic characteristics. A statistically significant correlation between clear cell renal cell carcinoma and tumor size was identified in 13 of 19 studies (63%). The accuracy of preoperative cross-sectional imaging was low in the 2 studies examining computed tomography (17%).

CONCLUSION

Benign renal tumors represent ∼15% of detected surgically resected renal masses and are more prevalent among small clinical T1a lesions. Noninvasive preoperative differentiation between more and less aggressive renal masses would be an important clinical advance that could allow clinicians greater diagnostic confidence and guide patient management through improved risk stratification.