Small renal masses progressing to metastases under active surveillance: a systematic review and pooled analysis

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.

Decisional Conflict Among Patients Newly Diagnosed With Clinical T1 Renal Masses: A Prospective Study

PURPOSE

Because multiple management options exist for clinical T1 renal masses, patients may experience a state of uncertainty about the course of action to pursue (ie, decisional conflict). To better support patients, we examined patient, clinical, and decision-making factors associated with decisional conflict among patients newly diagnosed with clinical T1 renal masses suspicious for kidney cancer.

MATERIALS AND METHODS

From a prospective clinical trial, participants completed the Decisional Conflict Scale (DCS), scored 0 to 100 with < 25 associated with implementing decisions, at 2 time points during the initial decision-making period. The trial further characterized patient demographics, health status, tumor burden, and patient-centered communication, while a subcohort completed additional questionnaires on decision-making. Associations of patient, clinical, and decision-making factors with DCS scores were evaluated using generalized estimating equations to account for repeated measures per patient.

RESULTS

Of 274 enrollees, 250 completed a DCS survey; 74% had masses ≤ 4 cm in size, while 11% had high-complexity tumors. Model-based estimated mean DCS score across both time points was 17.6 (95% CI 16.0-19.3), though 50% reported a DCS score ≥ 25 at least once. On multivariable analysis, DCS scores increased with age (+2.64, 95% CI 1.04-4.23), high- vs low-complexity tumors (+6.50, 95% CI 0.35-12.65), and cystic vs solid masses (+9.78, 95% CI 5.27-14.28). Among decision-making factors, DCS scores decreased with higher self-efficacy (-3.31, 95% CI -5.77 to -0.86]) and information-seeking behavior (-4.44, 95% CI -7.32 to -1.56). DCS scores decreased with higher patient-centered communication scores (-8.89, 95% CI -11.85 to -5.94).

CONCLUSIONS

In addition to patient and clinical factors, decision-making factors and patient-centered communication relate with decisional conflict, highlighting potential avenues to better support patient decision-making for clinical T1 renal masses.

Diagnostic accuracy of the Clear Cell Likelihood Score and selected MRI parameters in the characterization of indeterminate renal masses - a single-institution study

PURPOSE

We aimed to assess the diagnostic accuracy of the clear cell likelihood score (ccLS) and value of other selected magnetic resonance imaging (MRI) features in the characterization of indeterminate small renal masses (SRMs).

METHODS

Fifty patients with indeterminate SRMs discovered on MRI between 2012 and 2023 were included. The ccLS for the characterization of clear cell renal cell carcinoma (ccRCC) was calculated and compared to the final diagnosis (ccRCC vs. 'all other' masses).

RESULTS

The ccLS = 5 had a satisfactory accuracy of 64.0% and a very high specificity of 96.3%; however, its sensitivity of 26.1% was relatively low. Receiver operating curve (ROC) analysis revealed that from the selected MRI features, only T1 ratio and arterial to delayed enhancement (ADER) were good discriminators between ccRCC and other types of renal masses (area under curve, AUC = 0.707, p = 0.01; AUC = 0.673, p = 0.03; respectively). The cut-off points determined in ROC analysis using the Youden index were 0.73 (p = 0.01) for T1 ratio and 0.99 for ADER (p = 0.03). The logistic regression model demonstrated that ccLS = 5 and T1 ratio (OR = 15.5 [1.1-218.72], p = 0.04; OR = 0.002 [0.00-0.81], p = 0.04) were significant predictors of ccRCC.

CONCLUSIONS

The ccLS algorithm offers an encouraging method for the standardization of imaging protocols to aid in the diagnosis and management of SRMs in daily clinical practice by enhancing detectability of ccRCC and reducing the number of unnecessary invasive procedures for benign or indolent lesions. However, its diagnostic performance needs multi-center large cohort studies to validate it before it can be incorporated as a diagnostic algorithm and will guide future iterations of clinical guidelines. The retrospective nature of our study and small patient population confined to a single clinical center may impact the generalizability of the results; thus, future studies are required to define whether employment of the T1 ratio or ADER parameter may strengthen the diagnostic accuracy of ccRCC diagnosis.

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.

The Impact of a Multidisciplinary Tumor Board (MTB) on Treatment Decision Making for Patients With Renal Cell Carcinoma (RCC): 5-Year Data Analysis

OBJECTIVE

To describe the impact of a multidisciplinary tumor board (MTB) for renal cell carcinoma (RCC) patients in a locoregional renal cancer network by evaluating shared decision making (SDM) and adherence to MTB recommendations.

DESIGN, SETTING AND PARTICIPANTS

This prospective cohort study included all cases from a Dutch renal cancer network with suspicion of or histologically confirmed RCC discussed in MTBs between 2017-2022. Main endpoints were distribution of cases presented, proportion of recommendations with multiple treatment options enabling shared decision making (SDM), definite treatment after SDM and adherence to MTB recommendations. Further endpoints were definite treatment per tumor stage stratified by age and inclusion in clinical trials. Outcomes were displayed as means and proportions (%). Pearson's Chi-Squared test was used to analyze the effect of age on definite treatment advice.

RESULTS

Overall, 2651 cases were discussed, of which 1900 (72%) were new referrals and 751 (28%) rediscussions. Majority of cases were cT1a-b tumors (46%) and 22% were local recurrences or metachronous metastatic. Adherence to MTB recommendation was 96% and in 30% multiple treatment options were recommended, allowing for SDM. In 45% of cases with cT1a tumors multiple treatment options were recommended by the MTB, resulting in (cryo)ablation (32%) and AS (30%) as most frequent definite treatments after SDM. Among patients with cT3-4 tumors the inclusion rate in clinical trials was 47%.

CONCLUSIONS

A network MTB creates opportunity to discuss multiple treatment options and clinical trials in SDM with patients at a high rate of adherence to MTB recommendation.

Active Surveillance of Small Renal Masses in a Large Danish Cohort: Assessing Proficiency in Patient Selection

Small renal masses (SRMs) are often benign or early-stage cancers with low metastatic potential. The risk of overtreating SRMs is a particular concern in elderly or comorbid patients, for whom the risks associated with active surveillance (AS) are lower than the risks of surgical management. The aim is to systematically analyse a large cohort of AS patients to provide valuable insights into patient selection and outcomes concerning delayed intervention (DI) and AS termination. We retrospectively analysed data from 563 AS patients across three institutions from 2012 to 2023. Patients were classified into three groups: those currently in AS (n=283), those who underwent DI (n=75), and those who terminated AS (n=205). DI patients were younger, and had larger initial tumour size and higher growth rates (GRs) than AS patients. A significant number of patients terminated their AS, mainly due to comorbidities and death from non-kidney cancer causes, suggesting unsuitability for initial AS enrolment. AS appears to be a safe initial management strategy for SRMs, with an overall low GR and only one patient developing metastasis. The patient selection for AS appears inconsistent, highlighting the need for improved criteria to identify AS candidates, especially considering comorbidities and the possibility of subsequent active treatment in the event of progression.

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.

Comparison of aggressiveness in central versus peripheral T1a clear-cell renal cell carcinoma

PURPOSE

This study aimed to estimate the difference between peripheral and central small renal lesions in terms of their oncologic potential.

METHODS

Cross-sectional retrospective analysis of patients with small renal masses (T1a) who underwent surgical treatment between January 2008 and July 2019 at the affiliated hospital. Only patients with ccRCC pathology were included. Cases were divided into 2 groups depending on tumor location (central or peripheral) based on the R.E.N.A.L and local nephrometry scoring. Presence of nodal involvement, distant metastases, ISUP grade and endophytic growth were defined as aggressiveness predictors. Statistical analyses was performed using a standard statistical software (IBM SPPS Statistics Ver. 22), with P < 0.05 considered statistically significant. Associations between tumor location and Fuhrman grade, exo-/endophytic growth, TNM classification, and type of operation were tested using the Pearson χ² test and 1-way ANOVA test.

RESULTS

Patients with centrally located tumors had a higher incidence of clinical and pathological lymph node involvement (P = 0.02, χ2 = 5.1). Patients in both groups had an equal number of distant metastases at the time of diagnosis (P = 0.3, χ2 = 0.8). The operation time was significantly longer in patients with central lesions, which obviously showed higher tumor complexity in this group (P < 0.005). Pathological evaluation revealed differences between ISUP grades in both groups (P < 0.005, χ2 = 29.9). Central masses were characterized by higher aggressiveness, indicating a worse prognosis. Furthermore, the cases in the first group were more often endophytic (P = 0.03, χ2 = 0.9). Nevertheless, this did not affect the surgical strategy in most cases with a tendency toward partial nephrectomy. Eventually, organ-sparing treatment was preferable in both groups (P = 0.13, χ2 = 2.29).

CONCLUSION

Centrally located kidney cancer has showed in present study a higher incidence of high ISUP grade, regional nodal involvement and endophytic growth type. Endophytic growth type was associated with worse ISUP grading. Distribution of ISUP grade was not age depended, thus showing no difference by this criterion, when comparing different age groups. Higher ISUP grade was strongly associated with presence of distant metastases in T1a kidney tumors. Further analysis is needed to investigate aggressiveness of centrally located T1a RCC, as it may influence current conservative management options.

Concordance between renal tumour biopsy and robotic-assisted partial and radical nephrectomy histology: a 10-year experience

We aimed to assess concordance between renal tumour biopsy (RTB) and surgical pathology from robotic-assisted partial nephrectomy (RAPN) or robotic-assisted radical nephrectomy (RARN). Patients with preoperative RTB undergoing RAPN or RARN for suspected malignancy (9 September 2013-9 September 2023) were enrolled retrospectively from three sites. Patients were excluded if the tumour had prior cryotherapy or if biopsy or nephrectomy histology were unavailable or inconclusive. The primary outcome was concordance with the presence/absence of malignancy. Secondary outcomes were concordance with tumour subtype, World Health Organisation nuclear grade (patients with RTB clear cell or papillary RCC only), false-negative rate, false-positive rate, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). In the enrolment period, 332 and 132 patients underwent RAPN and RARN, respectively. Of these, 160 received preoperative RTB, with nine patients excluded, leaving 151 eligible patients. Median age was 63 years, and 49 (32%) were female. On surgical specimens, 144 patients had malignant histology. RTB was highly concordant with presence/absence of malignancy (147/151, 97%). Concordance with tumour subtype occurred in 141 patients (93%), while concordance with nuclear grade was seen in 42/66 patients (64%, RTB grade missing in 53 patients). False-negative rate, false-positive rate, sensitivity, specificity, PPV, and NPV were 2%, 14%, 98%, 86%, 99%, and 67%, respectively. Limitations include absence of complication data and exclusion of patients biopsied without surgery. In patients undergoing RAPN or RARN, preoperative RTB has high concordance with surgical pathology, both in the presence of malignancy and RCC subtype.

Abbreviated MRI Protocols in the Abdomen and Pelvis

Abbreviated MRI (AMRI) protocols rely on the acquisition of a limited number of sequences tailored to a specific question. The main objective of AMRI protocols is to reduce exam duration and costs, while maintaining an acceptable diagnostic performance. AMRI is of increasing interest in the radiology community; however, challenges limiting clinical adoption remain. In this review, we will address main abdominal and pelvic applications of AMRI in the liver, pancreas, kidney, and prostate, including diagnostic performance, pitfalls, limitations, and cost effectiveness will also be discussed. Level of Evidence: 3 Technical Efficacy Stage: 3.

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.

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.

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.

Percutaneous Ablation of T1 Renal Masses: Comparative Local Control and Complications after Radiofrequency and Cryoablation

The efficacy and complication rates of percutaneous radiofrequency ablation (RFA) and cryoablation (CA) in the treatment of T1 renal masses in two Northern Italy hospitals were retrospectively investigated. Eighty-two patients with 80 T1a tumors and 10 T1b tumors treated with thermal ablation from 2015 through 2020 were included. A total of 43 tumors in 38 patients were treated with RFA (2.3 ± 0.9 cm), and 47 tumors in 44 patients were treated with CA (2.1 ± 0.8 cm). The mean follow-up observation period was 26 ± 19 months. The major complications and efficacy, as measured using the technical success and local tumor recurrence rates, were recorded. There were three (6.9%) technical failures with RFA and one (2.1%) with cryoablation (p = 0.30). Among the 40 tumors that were successfully treated with RFA, 1 tumor (2.5%) developed local tumor recurrence; 5/46 tumors that were treated with cryoablation (10.8%) developed local tumor recurrence (p = 0.17). T1b lesions (4.0 ± 0.7 cm) resulted in 1/6 technically unsuccessful cases with RFA and 0/4 with CA. No recurrent disease was detected in the T1b lesions. Major complications occurred after 2.3% (1/43) of RFAs and 0/47 of cryoablation procedures. RFA and cryoablation are both effective in the treatment of renal masses. Major complications with either procedure are uncommon.

The Judicious Use of Stereotactic Ablative Radiotherapy in the Primary Management of Localized Renal Cell Carcinoma

Localized renal cell carcinoma is primarily managed surgically, but this disease commonly presents in highly comorbid patients who are poor operative candidates. Less invasive techniques, such as cryoablation and radiofrequency ablation, are effective, but require percutaneous or laparoscopic access, while generally being limited to cT1a tumors without proximity to the renal pelvis or ureter. Active surveillance is another management option for small renal masses, but many patients desire treatment or are poor candidates for active surveillance. For poor surgical candidates, a growing body of evidence supports stereotactic ablative radiotherapy (SABR) as a safe and effective non-invasive treatment modality. For example, a recent multi-institution individual patient data meta-analysis of 190 patients managed with SABR estimated a 5.5% five-year cumulative incidence of local failure with one patient experiencing grade 4 toxicity, and no other grade ≥3 toxic events. Here, we discuss the recent developments in SABR for the management of localized renal cell carcinoma, highlighting key concepts of appropriate patient selection, treatment design, treatment delivery, and response assessment.

TRENDS IN SURGICAL MANAGEMENT OF RENAL NEOPLASMS: SINGLE CENTER RESULTS IN THE LAST DECADE

The majority of renal neoplasms can be treated surgically using open or minimally-invasive approach. Nephron-sparing surgery should be used when possible, regardless to the operative approach. In this retrospective study, we analyzed surgical trends of operative treatment of renal neoplasms in the period from February 2011 until December 2020. There were a total of 1031 procedures, 703 (68.2%) radical nephrectomies (RN) and 328 (31.8%) partial nephrectomies (PN). Laparoscopic approach was used in 211 (20.5%) (111 PN and 100 RN), while open approach was used in 820 (79.5%) (328 PN and 703 RN) cases. There were 12 procedures performed with the use of cardiopulmonary bypass and hypothermic arrest. The median operative time was 161 minutes for open RN and 158 for open PN, 160 for laparoscopic RN, and 162 for laparoscopic PN. The most common pathology was clear cell carcinoma in 693 (67.3%), papillary carcinoma in 115 (11.2%), chromophobe carcinoma in 67 (6.5%), oncocytoma in 46 (4.5%), and angiomyolipoma in 33 (3.2%) patients. Pathologically, pT1 stage was diagnosed in 56.9%, pT2 in 5.8%, pT3 in 22.4% and pT4 in 1.2% of patients. Regional lymphadenectomy was performed in 354 (34.3%) patients, among which lymph nodes were positive in 40 (11.3%) cases. Surgical margins were positive in 27 cases when PN was performed (8.2%). In conclusion, there was an ongoing raising trend in the number of procedures in general, and also in minimally invasive and nephron-sparing surgery in our study.

The Metastatic Risk of Renal Cell Carcinoma by Primary Tumor Size and Subtype

Background

Current data on the association between tumor size, subtype, and metastases, and thresholds for intervention, for renal cell carcinoma (RCC), are largely based on single-center nephrectomy registries that may under-represent those presenting with metastatic disease.

Objective

We sought to assess tumor size and histologic subtype in relation to metastatic status at presentation for patients with RCC.

Design setting and participants

Using Surveillance, Epidemiology and End Results cancer registry data, we identified patients with a diagnosis of RCC made between 2004 and 2019, and a known size of primary tumor. We used nodal and metastatic TNM staging to assess metastatic disease at presentation.

Outcome measurements and statistical analysis

We report the proportion of metastatic disease across varying tumor sizes for clear cell (ccRCC), papillary (pRCC), and chromophobe (chRCC) RCC. We also examine sarcomatoid RCC and RCC with sarcomatoid features (sarcRCC). Logistic regression models were used to model the likelihood of metastatic disease for each histologic subtype.

Results and limitations

Of 181 096 RCC patients included, 23 829 had metastatic disease. For any RCC, metastatic rates of 3.6%, 13.1%, 30.3%, and 45.1% were observed for tumors ≤4, 4-≤7, 7-≤10, and >10 cm, respectively. Metastatic rates of chRCC were low at even large sizes, 11.0% at >10 cm. In contrast, sarcRCC had high metastatic rates at all sizes, 27.1% at ≤4 cm. Metastatic rates for ccRCC and pRCC increased steadily above 3 cm. For any RCC and each evaluated subtype, tumor size was found to be associated with metastatic disease on logistic regression (p < 0.001).

Conclusions

The likelihood of a renal mass being metastatic varies greatly with both its subtype and size. We report higher likelihoods of metastatic disease across tumor sizes compared with what has been reported previously. These results may help clinicians pick appropriate thresholds for intervention and candidates for active surveillance.

Patient summary

We find that the metastatic probability of renal cell carcinoma varies greatly with subtype and increases with tumor size.

Impact of diabetes and chronic kidney disease on active surveillance outcomes for small renal masses: A cohort study

Introduction

The American Cancer Society estimates 79,000 individuals will be diagnosed with kidney cancer in 2022, most of which are initially found as small renal masses (SRMs). Proper management of SRM patients includes careful evaluation of risk factors such as medical comorbidities and renal function. To investigate the importance of these risk factors, we examined their effect on crossover to delayed intervention (DI) and overall survival (OS) in patients undergoing active surveillance (AS) for SRMs.

Methods

This is an Institutional Review Board-approved retrospective analysis of AS patients presented at kidney tumor conferences with SRMs between 2007 and 2017. Univariable and multivariable logistic regression analyses were performed to determine how factors including estimated glomerular filtration rate (eGFR), diabetes, and chronic kidney disease are associated with DI and OS.

Results

A total of 111 cases were reviewed. In general, AS patients were elderly and had significant comorbidities. On univariate analysis, intervention was more likely to occur in patients with a younger age (P = 0.01), better kidney function (P = 0.01), and higher tumor growth rates (GRs) (P = 0.02). Higher eGFR was associated with better survival (P = 0.03), while higher tumor GRs (P = 0.014), greater Charlson Comorbidity Index (P = 0.01), and larger tumors (P = 0.01) were associated with worse OS. Of the comorbidities, diabetes was found to be an independent predictor of worse OS (P = 0.01).

Conclusions

Patient-level factors - such as diabetes and eGFR - are associated with the rate of DI and OS among SRM patients. Consideration of these factors may facilitate better AS protocols and improve patient outcomes for those with SRMs.

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.

Radiofrequency Ablation, Cryoablation, and Microwave Ablation for the Treatment of Small Renal Masses: Efficacy and Complications

Over the last two decades the detection rate of small renal masses has increased, due to improving diagnostic accuracy, and nephron-sparing treatments have become the first-choice curative option for small renal masses. As a minimally invasive alternative, thermal ablation has increased in popularity, offering a good clinical outcome and low recurrence rate. Radiofrequency ablation, Cryoablation, and Microwave ablation are the main ablative techniques. All of them are mostly overlapping in term of cancer specific free survival and outcomes. These techniques require imaging study to assess lesions features and to plan the procedure: US, CT, and both of them together are the leading guidance alternatives. Imaging findings guide the interventional radiologist in assessing the risk of complication and possible residual disease after procedure. The purpose of this review is to compare different ablative modalities and different imaging guides, underlining the effectiveness, outcomes, and complications related to each of them, in order to assist the interventional radiologist in choosing the best option for the patient.

Urine Molecular Biomarkers for Detection and Follow-Up of Small Renal Masses

Active surveillance (AS) is the best strategy for small renal masses (SRMs) management; however, reliable methods for early detection and disease aggressiveness prediction are urgently needed. The aim of the present study was to validate DNA methylation biomarkers for non-invasive SRM detection and prognosis. The levels of methylated genes TFAP2B, TAC1, PCDH8, ZNF677, FLRT2, and FBN2 were evaluated in 165 serial urine samples prospectively collected from 39 patients diagnosed with SRM, specifically renal cell carcinoma (RCC), before and during the AS via quantitative methylation-specific polymerase chain reaction. Voided urine samples from 92 asymptomatic volunteers were used as the control. Significantly higher methylated TFAP2B, TAC1, PCDH8, ZNF677, and FLRT2 levels and/or frequencies were detected in SRM patients' urine samples as compared to the control. The highest diagnostic power (AUC = 0.74) was observed for the four biomarkers panel with 92% sensitivity and 52% specificity. Methylated PCDH8 level positively correlated with SRM size at diagnosis, while TFAP2B had the opposite effect and was related to SRM progression. To sum up, SRMs contribute significantly to the amount of methylated DNA detectable in urine, which might be used for very early RCC detection. Moreover, PCDH8 and TFAP2B methylation have the potential to be prognostic biomarkers for SRMs.

Predicting Oncologic Outcomes in Small Renal Tumors

BACKGROUND

Most patients diagnosed with renal cancer today present with small renal masses (SRMs). Although these patients have a low risk of dying from their disease and many are followed with active surveillance protocols, a small subset of renal cell carcinomas (RCCs) behave aggressively. Knowledge regarding features of aggressive behavior would enable better adoption of active surveillance strategies among these patients.

OBJECTIVE

We sought to improve prognostic models to predict metastasis-free survival after nephrectomy through focused analyses of clinicopathologic characteristics of SRMs associated with adverse outcomes.

DESIGN, SETTING, AND PARTICIPANTS

We identified consecutive patients with surgically resected SRMs (≤4 cm) at the University of Texas Southwestern Kidney Cancer Program between 1998 and 2020. In addition, we evaluated the ability of SRMs to form tumors when implanted in mice, an indicator of tumor aggressiveness.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We examined the clinicopathologic factors associated with metastasis including prospectively performed BAP1 immunohistochemistry at our Clinical Laboratory Improvement Amendments laboratory. Multivariable Cox proportional hazard regression was used to predict metastasis-free survival.

RESULTS AND LIMITATIONS

A total of 3900 evaluable nephrectomies (from 3674 ethnically diverse patients) were identified, of which 1984 (51%) were SRMs including 1720 RCC. Of these patients with RCC (SRMRCC), 1576 did not have synchronous or metachronous larger RCCs and among these, 37 (2%) developed metastases. SRMRCC that metastasized were significantly enriched for aggressive morphologic phenotypes and engrafted in mice at comparable rates as larger metastatic tumors. BAP1 loss remained significantly associated with metastasis-free survival after accounting for TNM (tumor-node-metastasis) stage and SSIGN (stage, size, grade, and necrosis) score in multivariable analysis.

CONCLUSIONS

We identified clinicopathologic features that influence metastasis-free survival for patients with SRMRCC. If validated independently, these data should assist with patient prognosis and help with active surveillance strategies.

PATIENT SUMMARY

We report the identification of features of aggressiveness in small renal tumors that influence the likelihood of metastases after surgery.

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.

The Role of Focal Therapy and Active Surveillance for Small Renal Mass Therapy

Small and low-grade renal cell carcinomas have little potential for metastasis and disease-related mortality. As a consequence, the main problem remains the use of appropriately tailored treatment for each individual patient. Surgery still remains the gold standard, but many clinicians are questioning this approach and present the advantages of focal therapy. The choice of treatment regimen remains a matter of debate. This article summarizes the current treatment options in the management of small renal masses.

An Evaluation of a Web-Based Decision Aid for Treatment Planning of Small Kidney Tumors: Pilot Randomized Controlled Trial

Background

Surgery is the most common treatment for localized small kidney masses (SKMs) up to 4 cm, despite a lack of evidence for improved overall survival. Nonsurgical management options are gaining recognition, as evidence supports the indolence of most SKMs. Decision aids (DAs) have been shown to improve patient comprehension of the trade-offs of treatment options and overall decision quality, and may improve consideration of all major options according to individual health priorities and preferences.

Objective

This pilot randomized controlled trial (RCT) primarily aims to evaluate the impact of a new web-based DA on treatment decisions for patients with SKM; that is, selection of surgical versus nonsurgical treatment options. Secondary objectives include an assessment of decision-making outcomes: decisional conflict, decision satisfaction, and an understanding of individual preferences for treatment that incorporate the trade-offs associated with surgical versus nonsurgical interventions.

Methods

Three phases comprise the construction and evaluation of a new web-based DA on SKM treatment. In phase 1, this DA was developed in print format through a multidisciplinary design committee incorporating patient focus groups. Phase 2 was an observational study on patient knowledge and decision-making measures after randomization to receive the printed DA or institutional educational materials, which identified further educational needs applied to a web-based DA. Phase 3 will preliminarily evaluate the web-based DA: in a pilot RCT, 50 adults diagnosed with SKMs will receive the web-based DA or an existing web-based institutional website at urology clinics at a large academic medical center. The web-based DA applies risk communication and information about diagnosis and treatment options, elicits preferences regarding treatment options, and provides a set of options to consider with their doctor based on a decision-analytic model of benefits/harm analysis that accounts for comorbidity, age group, and tumor features. Questionnaires and treatment decision data will be gathered before and after viewing the educational material.

Results

This phase will consist of a pilot RCT from August 2022 to January 2023 to establish feasibility and preliminarily evaluate decision outcomes. Previous study phases from 2018 to 2020 supported the feasibility of providing the printed DA in urology clinics before clinical consultation and demonstrated increased patient knowledge about the diagnosis and treatment options and greater likelihood of favoring nonsurgical treatment just before consultation. This study was funded by the National Cancer Institute. Recruitment will begin in August 2022.

Conclusions

A web-based DA has been designed to address educational needs for patients making treatment decisions for SKM, accounting for comorbidities and treatment-related benefits and risks. Outcomes from the pilot trial will evaluate the potential of a web-based DA in personalizing treatment decisions and in helping patients weigh attributes of surgical versus nonsurgical treatment options for their SKMs.

Trial Registration

ClinicalTrials.gov NCT05387863; https://clinicaltrials.gov/ct2/show/NCT05387863

International Registered Report Identifier (IRRID)

PRR1-10.2196/41451

The multispeciality approach to the management of localised kidney cancer

Historically, kidney cancer was approached in a siloed single-speciality way, with urological surgeons managing the localised stages of the disease and medical oncologists caring for patients if metastases developed. However, improvements in the management of localised kidney cancer have occurred rapidly over the past two decades with greater understanding of the disease biology, diagnostic options, and innovations in curative treatments. These developments are favourable for patients but provide a substantially more complex landscape for patients and clinicians to navigate, with associated challenging decisions about who to treat, how, and when. As such, the skill sets needed to manage the various aspects of the disease and guide patients appropriately outstrips the capabilities of one particular specialist, and the evolution of a multispeciality approach to the management of kidney cancer is now essential. In this Review, we summarise the current best multispeciality practice for the management of localised kidney cancer and the areas in need of further research and development.

Benefit and Harm of Active Surveillance for Biopsy-proven Renal Oncocytoma: A Systematic Review and Pooled Analysis

Context

Active surveillance (AS) of biopsy-proven renal oncocytomas may reduce overtreatment. However, on biopsy, the risk of misdiagnosis owing principally to entities with peculiar hybrids and overlap morphology, and phenotypes argues for early intervention.

Objective

To assess the benefit and harm of AS in biopsy-proven renal oncocytoma.

Evidence acquisition

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). We systematically searched PubMed, Scopus, and Web of Science databases from September 26 up to October 2021, for studies that analyzed the outcomes of AS in patients with biopsy-proven renal oncocytoma.

Evidence synthesis

A total of ten studies with 633 patients met our inclusion criteria and were included for analysis. After a median follow-up of 34.5 mo (95% confidence interval [CI] 30.6–38.4), the overall definitive treatment rate from AS to definitive treatment was 17.3% (n = 75/433, six studies). The pooled pathological agreement between the initial renal mass biopsy and the surgical pathology report was 91.1%. The main indications for surgery during follow-up were rapid tumor growth and patient request. The pooled median growth rate was 1.55 mm/yr (95% CI 0.9–2.2). No metastasis or death related to renal oncocytoma was reported.

Conclusions

Annual tumor growth of biopsy-proven renal oncocytoma is low. AS is oncologically safe, with favorable compliance of patients. Crossover to definitive treatment revealed a strong concordance between biopsy and final pathology. Further studies on the long-term outcomes of AS are needed.

Patient summary

In this study, we examined the benefit and harm of active surveillance (AS) in biopsy-proven oncocytoma. Based on the available data, AS appears oncologically safe and may represent a promising alternative to immediate treatment. Patients should be included in AS decision discussions.

Development and Pilot Evaluation of a Decision Aid for Small Kidney Masses

OBJECTIVE

To develop and pilot test a patient decision aid (DA) describing small kidney masses and risks and benefits of treatment for the masses.

METHODS

An expert committee iteratively designed a small kidney mass DA, incorporating evidence-based risk communication and informational needs for treatment options and shared decision making. After literature review and drafting content with the feedback of urologists, radiologists, and an internist, a rapid qualitative assessment was conducted using two patient focus groups to inform user-centered design. In a pilot study, 30 patients were randomized at the initial urologic consultation to receive the DA or existing institutional patient educational material (PEM). Preconsultation questionnaires captured patient knowledge and shared decision-making preferences. After review of the DA and subsequent clinician consultation, patients completed questionnaires on discussion content and satisfaction. Proportions between arms were compared using Fisher exact tests, and decision measures were compared using Mann-Whitney tests.

RESULTS

Patient informational needs included risk of tumor growth during active surveillance and ablation, significance of comorbidities, and posttreatment recovery. For the DA, 84% of patients viewed all content, and mean viewing time was 20 min. Significant improvements in knowledge about small mass risks and treatments were observed (mean total scores: 52.6% DA versus 22.3% PEM, P < .001). DA use also increased the proportion of patients discussing ablation (66.7% DA versus 18.2% PEM, P = .02). Decision satisfaction measures were similar in both arms.

DISCUSSION

Patients receiving a small kidney mass DA are likely to gain knowledge and preparedness to discuss all treatment options over standard educational materials.

Metastatic Potential of Small Testicular Germ Cell Tumors: Implications for Surveillance of Small Testicular Masses

Patient summary

ACR Appropriateness Criteria® Post-Treatment Follow-up and Active Surveillance of Clinically Localized Renal Cell Carcinoma: 2021 Update

Renal cell carcinoma (RCC) accounts for most malignant renal tumors and is considered the most lethal of all urologic cancers. For follow-up of patients with treated or untreated RCC and those with neoplasms suspected to represent RCC, radiologic imaging is the most valuable component of surveillance, as most relapses and cases of disease progression are identified when patients are asymptomatic. Understanding the strengths and limitations of the various imaging modalities for the detection of disease, recurrence, or progression is essential when planning follow-up regimens. This document addresses the appropriate imaging examinations for asymptomatic patients who have been treated for RCC with radical or partial nephrectomy or ablative therapies. It also discusses the appropriate imaging examinations for asymptomatic patients with localized biopsy-proven or suspected RCC undergoing active surveillance. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Diagnosis and Treatment of Small Renal Masses: Where Do We Stand?

PURPOSE OF REVIEW

To present an overview of the current evidence-based studies covering diagnostic and management of SRM.

RECENT FINDINGS

Renal cell carcinoma (RCC) represents 3% of the cancers. Nowadays, partial nephrectomy (PN) represents gold standard treatment. New nephron-sparing approaches such as active surveillance and ablative therapies have been increasingly used as an alternative to surgical intervention. Due to novel comprehension of RCC and widespread use of imaging techniques, diagnosis at early stage in elderly patients has increased. Treatment decision-making should be based on patient and tumour characteristics. With expanding treatment options, the management of SRMs has become a debate and should be adjusted to patient and tumour characteristics. In a shared decision manner, both active surveillance with possible delayed intervention and focal therapy should be discussed with the patient as an alternative to partial nephrectomy.

Does histologic subtype impact overall survival in observed T1a kidney cancers compared with competing risks? Implications for biopsy as a risk stratification tool

OBJECTIVES

We sought to assess if adding a biopsy proven histologic subtype to a model that predicts overall survival that includes variables representing competing risks in observed, biopsy proven, T1a renal cell carcinomas, enhances the model's performance.

METHODS

The National Cancer Database was assessed (years 2004-2015) for patients with observed T1a renal cell carcinoma who had undergone renal mass biopsy. Kaplan-Meier curves were utilized to estimate overall survival stratified by histologic subtype. We utilized C-index from a Cox proportional hazards model to evaluate the impact of adding histologic subtypes to a model to predict overall survival for each stage.

RESULTS

Of 132 958 T1a renal masses identified, 1614 had biopsy proven histology and were managed non-operatively. Of those, 61% were clear cell, 33% papillary, and 6% chromophobe. Adjusted Kaplan-Meier curves demonstrated a difference in overall survival between histologic subtypes (P = 0.010) with greater median overall survival for patients with chromophobe (85.1 months, hazard rate 0.45, P = 0.005) compared to clear cell (64.8 months, reference group). Adding histology to a model with competing risks alone did not substantially improve model performance (C-index 0.65 vs 0.64 respectively).

CONCLUSIONS

Incorporation of histologic subtype into a risk stratification model to determine prognostic overall survival did not improve modeling of overall survival compared with variables representing competing risks in patients with T1a renal cell carcinoma managed with observation. These results suggest that performing renal mass biopsy in order to obtain tumor histology may have limited utility. Future studies should further investigate the overall utility of renal mass biopsy for observed T1a kidney cancers.

Overview of clinical management for older patients with renal cell carcinoma

The rapidly increasing pool of older patients being diagnosed with and surviving their cancer is creating many challenges. Regarding localized renal cell carcinoma, surgery is considered as gold standard treatment options even in older men, whereas active surveillance and ablation therapy are alternative options for a proportion of these patients. With regard to advanced disease, anti-vascular endothelial growth factor tyrosine kinase inhibitors (VEGFR-TKI) and immune check point inhibitor are standard treatment modalities, although treatment choice from multiple regimens and prevention of adverse events need to be considered. Better assessment techniques, such as comprehensive geriatric assessment to meet the unique needs of older patients, are a central focus in the delivery of high-quality geriatric oncology care. Through this process, shared decision-making should be adopted in clinical care to achieve optimal goals of care that reflect patient and caregiver hopes, needs and preferences. It is necessary to continue investigating oncological outcomes and complications associated with treatment in this population to ensure appropriate cancer care. In this narrative review, we completed a literature review of the various treatments for renal cell carcinoma in older patients that aimed to identify the current evidence related to the full range of the treatments including active surveillance, surgery, ablation therapy and systemic therapy. Prospectively designed studies and studies regarding geriatric assessment were preferentially added as references. Our goals were to summarize the real-world evidence and provide a decision framework that guides better cancer practices for older patients with renal cell carcinoma.

Real world outcomes of biopsy‐proven oncocytic neoplasm of the kidney managed by surveillance

Objectives

To evaluate outcomes of patients diagnosed with oncocytic renal neoplasms on routine renal mass biopsy and to describe the natural history of these tumours when managed with surveillance as opposed to immediate intervention. To report disease‐specific survival.

Patients and methods

Patients were identified from a retrospective review of pathology databases from three tertiary referral centres that utilise renal mass biopsy in routine clinical practice. All patients with biopsy‐proven oncocytic tumours were included and a retrospective review of online patient records was undertaken.

Results

There were 184 biopsy‐proven oncocytic renal neoplasms identified in 172 patients. There were two biopsy complications (both pneumothorax, Clavien–Dindo Grade I). Of these lesions, 135 were reported as oncocytomas or oncocytic renal neoplasms that were not further classified and 37 were reported as chromophobe carcinoma (ChRCC). The median age at diagnosis was 70 (33–88). The average tumour diameter at diagnosis was 33 mm. One hundred seven tumours were initially managed with surveillance (including 13 ChRCC) with a minimum follow‐up of 6 months and a median of 39 months (6–144) whereas 49 patients underwent immediate treatment. The mean growth rate across all oncocytic renal neoplasms managed by surveillance was 3 mm/year. There was no statistically significant difference in growth rates between oncocytic renal neoplasms and ChRCC. Thirteen patients with oncocytic renal neoplasms initially managed by surveillance moved on to an active management strategy during follow‐up. The clinical indication given for a change from surveillance was tumour growth in 12 cases and patient choice in 1 case. Where definitive pathology was available, there was 85% concordance with the biopsy. There were no cases of development of metastatic disease or disease‐related morbidity or mortality during the study.

Conclusions

This multicentre retrospective cohort study supports the hypothesis that selected biopsy‐proven oncocytic renal neoplasms can be safely managed with surveillance in the medium term. Routine renal mass biopsy may reduce surgery for benign or indolent renal tumours and the potential associated morbidity for these patients.

The value of sestamibi single-photon emission computed tomography/computed tomography in differentiating and staging renal cell carcinomas

Misdiagnosis of benign renal neoplasms can lead to unnecessary surgical resections, which increases the risk of other morbidities and mortality. Therefore, it is crucial to find a diagnostic modality for differentiation between benign and malignant renal masses. In the current study, we summarized published pieces of evidence concerning the use of technetium-99m (^99mTc)-sestamibi single-photon emission computed tomography/computed tomography (SPECT/CT) as a promising diagnostic nuclear imaging modality for the differentiation of renal neoplasms. The study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement for Systematic Reviews and Meta-Analyses. We conducted a systematic electronic database search for suitable studies from inception till February 20, 2020 in 9 databases. The risk of bias was assessed for the included studies using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. We identified 9373 records after exclusion of 8978 duplicates using EndNote software. Title and abstract screening resulted in 761 records for further full-text screening. Finally, four studies were included with total sample size of 80 patients. The overall risk of bias was low to moderate. The results of all the included studies supported using ^99mTc-sestamibi SPECT/CT for the differentiation between benign and malignant renal neoplasms. The use of ^99mTc-sestamibi SPECT/CT could be a rapid, less invasive, promising diagnostic modality for histological diagnosis and staging of renal neoplasm, as well as monitoring post-therapy tumor's response. However, more studies with large sample sizes are essential to confirm the reliability and accuracy of this modality for usage.

The changing trends of image-guided biopsy of small renal masses before intervention-an analysis of European multinational prospective EuRECA registry

Objectives

To evaluate the use of pre-cryoablation biopsy for small renal masses (SRMs) and the effects of increasing uptake on histological results of treated SRMs.

Methods

From 2015 to 2019, patients with sporadic T1N0M0 SRMs undergoing percutaneous, laparoscopic, or open cryoablation from 14 European institutions within the European Registry for Renal Cryoablation (EuRECA) were included for the retrospective analysis. Univariate and multivariate logistic models were used to evaluate the trends, histological results, and the factors influencing use of pre-cryoablation biopsy.

Results

In total, 871 patients (median (IQR) age, 69 (14), 298 women) undergoing cryoablation were evaluated. The use of pre-cryoablation biopsy has significantly increased from 42% (65/156) in 2015 to 72% (88/122) in 2019 (p < 0.001). Patients treated for a benign histology are significantly more likely to have presented later in the trend, where pre-cryoablation biopsy is more prevalent (OR: 0.64, 95% CI 0.51–0.81, p < 0.001). Patients treated for undiagnosed histology are also significantly less likely to have presented in 2018 compared to 2016 (OR 0.31, 95% CI 0.10–0.97, p = 0.044). Patients aged 70+ are less likely to be biopsies pre-cryoablation (p < 0.05). R.E.N.A.L. nephrometry score of 10+ and a Charlson Comorbidity Index > 1 are factors associated with lower likelihood to not have received a pre-cryoablation biopsy (p < 0.05).

Conclusion

An increased use of pre-cryoablation biopsy was observed and cryoablation patients treated with a benign histology are more likely to have presented in periods where pre-cryoablation biopsy is not as prevalent. Comparative studies are needed to draw definitive conclusions on the effect of pre-cryoablation biopsy on SRM treatments.

Key Points

• The use of biopsy pre-ablation session has increased significantly from 42% of all patients in 2015 to 74% in 2019.

• Patients are less likely to be treated for a benign tumour if they presented later in the trend, where pre-cryoablation biopsy is more prevalent, compared to later in the trend (OR 0.64, 95% CI 0.51–0.81, p < 0.001).

• Patients with comorbidities or a complex tumour (R.E.N.A.L. nephrometry score > 10) are less likely to not undergo biopsy as a separate session to cryoablation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-022-08556-2.

Renal Mass Biopsy

Kidney cancer accounts for 2% of cancer related deaths. Historically, a patient with a solid renal mass would undergo surgery without biopsy given the previously low diagnostic yield of biopsy and the fear of tumor seeding. This led to a high rate of resection for benign masses. With the rising incidence of renal masses discovered on imaging, improvements in biopsy technique and advancements in pathologic evaluation of biopsy samples of renal masses, renal mass biopsy now plays an important role in selected patients with renal masses. Coaxial core needle biopsy is the preferred technique with a low rate of complications and a high diagnostic yield. This article will discuss indications, methods, utility, limitations and complications of renal mass biopsy.

How We Do It: Managing the Indeterminate Renal Mass with the MRI Clear Cell Likelihood Score

The widespread use of cross-sectional imaging has led to a continuous increase in the number of incidentally detected indeterminate renal masses. Frequently, these clinical scenarios involve an older patient with comorbidities and a small renal mass (≤4 cm). Despite aggressive treatment in early stages of the disease, a clear positive effect in reducing kidney cancer-specific mortality is lacking, indicating that many renal cancers exhibit an indolent oncologic behavior. Furthermore, in general, one in five small renal masses is histologically benign and may not benefit from aggressive treatment. Although active surveillance is increasingly recognized as a management option for some patients, the absence of reliable clinical and imaging predictive biologic markers of aggressiveness can contribute to patient anxiety and limit its use in clinical practice. A standardized approach to the image interpretation of solid renal masses has not been broadly implemented. The clear cell likelihood score (ccLS) derived from multiparametric MRI is useful in noninvasively identifying the clear cell subtype, the most common and aggressive form of kidney cancer. Herein, a review of the ccLS is presented, including a step-by-step guide for image interpretation and additional guidance for its implementation in clinical practice.

Active Surveillance of Renal Masses: The Role of Radiology

Active surveillance of renal masses, which includes serial imaging with the possibility of delayed treatment, has emerged as a viable alternative to immediate therapeutic intervention in selected patients. Active surveillance is supported by evidence that many benign masses are resected unnecessarily, and treatment of small cancers has not substantially reduced cancer-specific mortality. These data are a call to radiologists to improve the diagnosis of benign renal masses and differentiate cancers that are biologically aggressive (prompting treatment) from those that are indolent (allowing treatment deferral). Current evidence suggests that active surveillance results in comparable cancer-specific survival with a low risk of developing metastasis. Radiology is central in this. Imaging is used at the outset to estimate the probability of malignancy and degree of aggressiveness in malignant masses and to follow up masses for growth and morphologic change. Percutaneous biopsy is used to provide a more definitive histologic diagnosis and to guide treatment decisions, including whether active surveillance is appropriate. Emerging applications that may improve imaging assessment of renal masses include standardized assessment of cystic and solid masses and radiomic analysis. This article reviews the current and future role of radiology in the care of patients with renal masses undergoing active surveillance.

Evidence-based Urology: Trustworthy Guidelines

Clinical guidelines for guiding clinical decision-making must be trustworthy, especially when there is controversy or a shifting paradigm. In urology, the management of small renal masses is one area in which there is currently a paradigm shift towards active surveillance. A number of international guidelines address this paradigm shift to some extent, with varying degrees of rigor. To be trustworthy, guidelines should be developed by panels that include content experts - the traditional panel members - as well as methodologists with expertise in evidence interpretation, front-line clinicians who take care of the patients who constitute the target audience, and patient partners. At a minimum, panels should integrate four key concepts: (1) guidelines provide a systematic summary of evidence used to support answerable questions, including assessment of the quality of the evidence; (2) there is a clear and transparent link between the evidence and recommendations; (3) recommendations incorporate patient values and preferences; and (4) conflicts of interest are managed optimally. In this article we address several issues in four international guidelines, with an emphasis on guideline methods and implications for guidance statements. The strengths and limitations of available recommendations are reviewed and summarized with suggestions for improving the next iterations of guidelines on the management of small renal masses. PATIENT SUMMARY: Good clinical decision-making relies on trustworthy guidelines. We assessed four international guidelines on the management of small kidney tumors that illustrate some of the key issues in developing a trustworthy guideline. Patient values and preferences are under-represented in most clinical guidelines.

Cross-sectional imaging assessment of renal masses with emphasis on MRI

Magnetic resonance imaging (MRI) is a useful complementary imaging tool for the diagnosis and characterization of renal masses, as it provides both morphologic and functional information. A core MRI protocol for renal imaging should include a T1-weighted sequence with in- and opposed-phase images (or, alternatively with DIXON technique), T2-weighted and diffusion-weighted images as well as a dynamic contrast-enhanced sequence with subtraction images, followed by a delayed post-contrast T1-weighted sequence. The main advantages of MRI over computed tomography include increased sensitivity for contrast enhancement, less sensitivity for detection of calcifications, absence of pseudoenhancement, and lack of radiation exposure. MRI may be applied for renal cystic lesion characterization, differentiation of renal cell carcinoma (RCC) from benign solid renal tumors, RCC histologic grading, staging, post-treatment follow-up, and active surveillance of patients with treated or untreated RCC.

Disease Progression in Older Patients With Renal Tumor Assigned to an Active Surveillance Protocol

BACKGROUND

Active surveillance (AS) is a validated option for the treatment of small renal masses (SMRs), especially in older patients. This study investigates the oncologic outcomes and competitive mortality of older patients prospectively assigned to AS.

METHODS

We conducted a monocentric study on patients ≥75 years treated between 2011 and 2016 for a SMR. Treatment modalities, biopsy data, survivals (overall, specific, cancer progression) and delayed interventions were analyzed.

RESULTS

Overall, 106 patients (median age 80.5 years) were included, of which 41 were managed by AS during a follow-up of 3.4 years [0-7.1]. Seven patients (17%) had a primary biopsy with 3 confirmed renal cell carcinomas. Fourteen patients (34.1%) presented with progression (29.2% local; 4.9% metastatic), 8 (19.5%) requiring delayed interventions (75% ablative therapy and 25% radical nephrectomy). Overall survival (OS) was 68.3% and cancer specific survival was 95.1% during the study period. Competitive mortality was higher (84.6%) than cancer specific mortality (15.4%), P = .001.

CONCLUSION

The growth rate of progression including 4.9% metastatic progression underlines the value of AS compared to simple watchful surveillance in the treatment of SMRs in older patients. Of note, the higher competitive mortality confirm that AS should be preferred to active intervention at the beginning of the management.

Survival benefits analyses of T1a renal cell carcinoma patients treated with microwave ablation

PURPOSE

The individual decision-making reference of Microwave ablation (MWA) for T1a RCC treatment is not clear, and it may not benefit all the patients equally. Therefore, we quantitatively evaluated the distinct survival benefits of patients with T1a RCC stratified by survival predictors.

MATERIALS AND METHODS

A total of 237 patients with T1a RCC who underwent MWA over the last 16 years were retrospectively reviewed for survival benefit analysis. Cox proportional hazard models were used to control for the prognostic variables of OS, CSS, and PFS. Survival rates were calculated using the Kaplan-Meier method and compared by log-rank analysis. Linear extrapolation was used to compute median survival periods.

RESULTS

The OS benefit was significantly dependent on age (HR:2.499, 95% CI: 1.245-5.016, p = 0.010) and age-adjusted Charlson comorbidity index (CCI) score (HR:3.956, 95% CI, 1.409-11.110, p = 0.009). OS in patients aged <75 years or with an age-adjusted CCI score <7 was significantly prolonged (44.68, 65.55 months) compared to OS in patients aged ≥75 years or with CCI score ≥7 (p < 0.001 for both). PFS benefit was significantly dependent on age-adjusted CCI (HR:3.325, 95% CI, 1.390-7.956, p = 0.007), patient type (HR:0.4, 95% CI, 0.214-0.745, p = 0.004), and tumour growth pattern (HR:12.562, 95% CI, 1.552-101.696, p = 0.018). PFS in incipient patients was significantly prolonged (33.75 months) compared to that in the relapsed patients (p = 0.037). Patients with an age-adjusted CCI score <7 or without tumour protruding into the renal pelvis, lived free from recurrence or metastasis (55.69 or 101.61 months) longer than that in patients with an age-adjusted CCI score ≥7 or with tumour protruding into the renal pelvis (p < 0.01 for both). None of the variables was associated with CSS benefit.

CONCLUSIONS

The OS and PFS benefits from MWA were not equal for all T1a RCC patients. Age ≥75 years and age-adjusted CCI ≥ 7 significantly shortened OS. Age-adjusted CCI ≥ 7, relapsed RCC, and RCC protruding into the renal pelvis significantly shortened the PFS period. For a better survival prognosis, appropriate patient triage is still needed.