Thermal Ablation Versus Partial Nephrectomy for cT1 Renal Mass in a Solitary Kidney: A Matched Cohort Comparative Analysis.

BACKGROUND: Nephron-sparing approaches are preferred for renal mass in a solitary kidney (RMSK), with partial nephrectomy (PN) generally prioritized. Thermal ablation (TA) also is an option for small renal masses in this setting; however, comparative functional/survival outcomes are not well-defined. METHODS: A retrospective study of 504 patients (1975-2022) with cT1 RMSK managed with PN (n = 409)/TA (n = 95) with necessary data for analysis was performed. Propensity score was used for matching patients, including age, preoperative glomerular filtration rate (GFR), tumor diameter, R.E.N.A.L. ((R)adius (tumor size as maximal diameter), (E)xophytic/endophytic properties of tumor, (N)earness of tumor deepest portion to collecting system or sinus, (A)nterior (a)/posterior (p) descriptor, and (L)ocation relative to polar lines), and comorbidities. Functional outcomes were compared, and Kaplan-Meier was used to analyze survival. RESULTS: The matched cohort included 132 patients (TA = 66/PN = 66), with median tumor diameter of 2.4 cm, R.E.N.A.L. of 6, and preoperative GFR of 52 ml/min/1.73 m2. Acute kidney injury occurred in 11%/61% in the TA/PN cohorts, respectively (p < 0.01). After recovery, median GFR preserved was 89%/83% for TA/PN, respectively (p = 0.02), and 5-year dialysis-free survival was 96% in both cohorts. Median follow-up was 53 months. Five-year recurrence-free survival (RFS) was 62%/86% in the TA/PN cohorts, respectively (p < 0.01). Five-year local recurrence (LR)-free survival was 74%/95% in the TA/PN cohorts, respectively (p < 0.01). Five-year cancer-specific survival (CSS) was 96%/98% in the TA/PN cohorts, respectively (p = 0.7). Local recurrence was observed in nine of 36 (25%) and five of 30 (17%) patients managed with laparoscopic versus percutaneous TA, respectively. For TA with LR (n = 14), nine patients presented with multifocality and/or cT1b tumors. Twelve LR were managed with salvage TA, and seven remained cancer-free, while five developed systemic recurrence, three with concomitant LR. CONCLUSIONS: Functional outcomes for TA for RMSK were improved compared with PN. Local recurrence was more common after TA and often was associated with the laparoscopic approach, multifocality, and large tumor size. Improved patient selection and greater experience with TA should improve outcomes. Salvage of LR was not always possible. Partial nephrectomy remains the reference standard for RMSK.

Parenchymal volume preservation during partial nephrectomy: improved methodology to assess impact and predictive factors.

OBJECTIVE: To rigorously evaluate the impact of the percentage of parenchymal volume preserved (PPVP) and how well the preserved parenchyma recovers from ischaemia (Recischaemia ) on functional outcomes after partial nephrectomy (PN) using an accurate and objective software-based methodology for estimating parenchymal volumes and split renal function (SRF). A secondary objective was to assess potential predictors of the PPVP. PATIENTS AND METHODS: A total of 894 PN patients with available studies (2011-2014) were evaluated. The PPVP was measured from cross-sectional imaging at ≤3 months before and 3-12 months after PN using semi-automated software. Pearson correlation evaluated relationships between continuous variables. Multivariable linear regression evaluated predictors of ipsilateral glomerular filtration rate (GFR) preserved and the PPVP. Relative-importance analysis was used to evaluate the impact of the PPVP on ipsilateral GFR preserved. Recischaemia was defined as the percentage of ipsilateral GFR preserved normalised by the PPVP. RESULTS: The median tumour size and R.E.N.A.L. nephrometry score were 3.4 cm and 7, respectively. In all, 49 patients (5.5%) had a solitary kidney. In all, 538 (60%)/251 (28%)/104 (12%) patients were managed with warm/cold/zero ischaemia, respectively. The median pre/post ipsilateral GFRs were 40/31 mL/min/1.73 m2 , and the median (interquartile range [IQR]) percentage of ipsilateral GFR preserved was 80% (71-88%). The median pre/post ipsilateral parenchymal volumes were 181/149 mL, and the median (IQR) PPVP was 84% (76-92%). In all, 330 patients (37%) had a PPVP of <80%, while only 34 (4%) had a Recischaemia of <80%. The percentage of ipsilateral GFR preserved correlated strongly with the PPVP (r = 0.83, P < 0.01) and loss of parenchymal volume accounted for 80% of the loss of ipsilateral GFR. Multivariable analysis confirmed that the PPVP was the strongest predictor of ipsilateral GFR preserved. Greater tumour size and endophytic and nearness properties of the R.E.N.A.L. nephrometry score were associated with a reduced PPVP (all P ≤ 0.01). Solitary kidney and cold ischaemia were associated with an increased PPVP (all P < 0.05). CONCLUSIONS: A reduced PPVP predominates regarding functional decline after PN, although a low Recischaemia can also contribute. Tumour-related factors strongly influence the PPVP, while surgical efforts can improve the PPVP as observed for patients with solitary kidneys.

Body morphometry may predict parastomal hernia following radical cystectomy with ileal conduit.

OBJECTIVE: To investigate whether preoperative body morphometry analysis can identify patients at risk of parastomal hernia (PH), which is a common complication after radical cystectomy (RC). PATIENTS AND METHODS: All patients who underwent RC between 2010 and 2020 with available cross-sectional imaging preoperatively and at 1 and 2 years postoperatively were included. Skeletal muscle mass and total fat mass (FM) were determined from preoperative axial computed tomography images obtained at the level of the L3 vertebral body using Aquarius Intuition software. Sarcopenia and obesity were assigned based on consensus definitions of skeletal muscle index (SMI) and FM index (FMI). PH were graded using both the Moreno-Matias and European Hernia Society criteria. Binary logistic regression and recursive partitioning were used to identify patients at risk of PH. The Kaplan-Meier method with log-rank and Cox proportional hazards models included clinical and image-based parameters to identify predictors of PH-free survival. RESULTS: A total of 367 patients were included in the final analysis, with 159 (43%) developing a PH. When utilising binary logistic regression, high FMI (odds ratio [OR] 1.63, P < 0.001) and low SMI (OR 0.96, P = 0.039) were primary drivers of risk of PH. A simplified model that only relied upon FMI, SMI, and preoperative albumin improved the classification of patients at risk of PH. On Kaplan-Meier analysis, patients who were obese or obese and sarcopenic had significantly worse PH-free survival (P < 0.001). CONCLUSION: Body morphometry analysis identified FMI and SMI to be the most consistent predictors of PH after RC.

Parenchymal volume analysis to assess longitudinal functional decline following partial nephrectomy.

OBJECTIVE: To identify factors associated with longitudinal ipsilateral functional decline after partial nephrectomy (PN). PATIENTS AND METHODS: Of 1140 patients managed with PN (2012-2014), 349 (31%) had imaging/serum creatinine levels pre-PN, 1-12 months post-PN (new baseline), and >3 years later necessary for inclusion. Parenchymal-volume analysis was used to determine split renal function. Patients were grouped as having significant renal comorbidity (CohortSRC : diabetes mellitus with insulin-dependence or end-organ damage, refractory hypertension, or severe pre-existing chronic kidney disease) vs not having significant renal comorbidity (CohortNoSRC ) preoperatively. Multivariable regression was used to identify predictors of annual ipsilateral parenchymal atrophy and functional decline relative to new baseline values post-PN, after the kidney had healed. RESULTS: The median follow-up was 6.3 years with 87/226/36 patients having cold/warm/zero ischaemia. The median cold/warm ischaemia times were 32/22 min. Overall, the median tumour size was 3.0 cm. The preoperative glomerular filtration rate (GFR) and new baseline GFR (NBGFR) were 81 and 71 mL/min/1.73 m2 , respectively. After establishment of the NBGFR, the median loss of global and ipsilateral function was 0.7 and 0.4 mL/min/1.73 m2 /year, respectively, consistent with the natural ageing process. Overall, the median ipsilateral parenchymal atrophy was 1.2 cm3 /year and accounted for a median of 53% of the annual functional decline. Significant renal comorbidity, age, and warm ischaemia were independently associated with ipsilateral parenchymal atrophy (all P < 0.01). Significant renal comorbidity and ipsilateral parenchymal atrophy were independently associated with annual ipsilateral functional decline (both P < 0.01). Annual median ipsilateral parenchymal atrophy and functional decline were both significantly increased for CohortSRC compared to CohortNoSRC (2.8 vs 0.9 cm3 , P < 0.01 and 0.90 vs 0.30 mL/min/1.73 m2 /year, P < 0.01, respectively). CONCLUSIONS: Longitudinal renal function following PN generally follows the normal ageing process. Significant renal comorbidities, age, warm ischaemia, and ipsilateral parenchymal atrophy were the most important predictors of ipsilateral functional decline following establishment of NBGFR.

Functional recovery after partial nephrectomy: next generation analysis.

OBJECTIVES: To provide a more rigorous assessment of factors affecting functional recovery after partial nephrectomy (PN) using novel tools that allow for analysis of more patients and improved accuracy for assessment of parenchymal volume loss, thereby revealing the potential impact of secondary factors such as ischaemia. PATIENTS AND METHODS: Of 1140 patients managed with PN (2012-2014), 670 (59%) had imaging and serum creatinine levels measured before and after PN necessary for inclusion. Recovery from ischaemia was defined as the ipsilateral glomerular filtration rate (GFR) saved normalised by parenchymal volume saved. Acute kidney injury was assessed through Spectrum Score, which quantifies the degree of acute ipsilateral renal dysfunction due to exposure to ischaemia that would otherwise be masked by the contralateral kidney. Multivariable regression was used to identify predictors of Spectrum Score and Recovery from Ischaemia. RESULTS: In all, 409/189/72 patients had warm/cold/zero ischaemia, respectively, with median (interquartile range [IQR]) ischaemia times for cold and warm ischaemia of 30 (25-42) and 22 (18-28) min, respectively. The median (IQR) global preoperative GFR and new baseline GFR (NBGFR) were 78 (63-92) and 69 (54-81) mL/min/1.73 m2 , respectively. The median (IQR) ipsilateral preoperative GFR and NBGFR were 40 (33-47) and 31 (24-38) mL/min/1.73 m2 , respectively. Functional recovery correlated strongly with parenchymal volume preserved (r = 0.83, P < 0.01). The median (IQR) decline in ipsilateral GFR associated with PN was 7.8 (4.5-12) mL/min/1.73 m2 with loss of parenchyma accounting for 81% of this loss. The median (IQR) recovery from ischaemia was similar across the cold/warm/zero ischaemia groups at 96% (90%-102%), 95% (89%-101%), and 97% (91%-102%), respectively. Independent predictors of Spectrum Score were ischaemia time, tumour complexity, and preoperative global GFR. Independent predictors of recovery from ischaemia were insulin-dependent diabetes mellitus, refractory hypertension, warm ischaemia, and Spectrum Score. CONCLUSIONS: The main determinant of functional recovery after PN is parenchymal volume preservation. A more robust and rigorous evaluation allowed us to identify secondary factors including comorbidities, increased tumour complexity, and ischaemia-related factors that are also independently associated with impaired recovery, although altogether these were much less impactful.

Neocapsular reconstruction for challenging partial nephrectomy: A feasibility study in a porcine model and recent clinical experience.

OBJECTIVES: Multifocal renal masses and large central-endophytic tumors can be challenging for partial nephrectomy (PN) due to the paucity of capsule remaining after tumor removal. Our objective was to develop a neocapsule to provide tamponade and test its feasibility/safety in a porcine model. METHODS: Eight live pigs (50-70 kg) underwent unclamped open right flank PN. Renal defects were 1 cm deep and had moderate ongoing venous bleeding. A 6 × 9 inch sheet of Nu-knit® was used for neocapsular reconstruction with Fibrillar™ packing to provide modest tamponade and preclude ongoing bleeding. Blood chemistry and hemoglobin (Hb) levels were drawn preoperatively and postoperative Days 3/5/8. On postoperative Day 8, euthanasia was performed, and both kidneys were inspected and analyzed for histologic changes. RESULTS: PN defects ranged from 1 × 1 × 1 cm to 4 × 2 × 1 cm; four pigs had PN performed in both poles and four in one pole. Neocapsular reconstruction was successful (n = 8), with no perioperative complications. Median baseline Hb was 10.4 g/dL, and median Hb postoperative Days 3/5/8 were 10.0/10.8/10.6 g/dL, respectively. Median baseline serum creatinine (SCr) was 1.9 mg/dL, and median SCr postoperative Days 3/5/8 were 1.5/1.4/1.5 mg/dL, respectively. At sacrifice, no significant hematomas were observed. Other than adjacent to the PN site, there were no significant histologic changes in the parenchyma for operative kidneys versus controls. Based on our experience, we recently performed neocapsular reconstruction safely/effectively after extensive PN for multifocal tumors and for an allograft with difficult-to-manage subcapsular hematoma. CONCLUSIONS: Neocapsular reconstruction after PN or capsular trauma appears feasible and safe and may be considered to reduce the risk of perioperative bleeding. However, further study will be needed to confirm the utility/efficacy of this approach.

New Baseline Renal Function after Radical or Partial Nephrectomy: A Simple and Accurate Predictive Model.

PURPOSE: Preoperative estimation of new baseline glomerular filtration rate after partial nephrectomy or radical nephrectomy for renal cell carcinoma has important clinical implications. However, current predictive models are either complex or lack external validity. We aimed to develop and validate a simple equation to estimate postoperative new baseline glomerular filtration rate. MATERIALS AND METHODS: For development and internal validation of the equation, a cohort of 7,860 patients with renal cell carcinoma undergoing partial nephrectomy/radical nephrectomy (2005-2015) at the Veterans Affairs National Health System was analyzed. Based on preliminary analysis of 94,327 first-year postoperative glomerular filtration rate measurements, new baseline glomerular filtration rate was defined as the final glomerular filtration rate within 3 to 12 months after surgery. Multivariable linear regression analyses were applied to develop the equation using two-thirds of the renal cell carcinoma Veterans Administration cohort. The simplest model with the highest coefficient of determination (R2) was selected and tested. This model was then internally validated in the remaining third of the renal cell carcinoma Veterans Administration cohort. Correlation/bias/accuracy/precision of equation were examined. For external validation, a similar cohort of 3,012 patients with renal cell carcinoma from an outside tertiary care center (renal cell carcinoma-Cleveland Clinic) was independently analyzed. RESULTS: New baseline glomerular filtration rate (in ml/minute/1.73 m2) can be estimated with the following simplified equation: new baseline glomerular filtration rate = 35 + preoperative glomerular filtration rate (× 0.65) - 18 (if radical nephrectomy) - age (× 0.25) + 3 (if tumor size >7 cm) - 2 (if diabetes). Correlation/bias/accuracy/precision were 0.82/0.00/83/-7.5-8.4 and 0.82/-0.52/82/-8.6-8.0 in the internal/external validation cohorts, respectively. Additionally, the area under the curve (95% confidence interval) to discriminate postoperative new baseline glomerular filtration rate ≥45 ml/minute/1.73 m2 from receiver operating characteristic analyses were 0.90 (0.88, 0.91) and 0.90 (0.89, 0.91) in the internal/external validation cohorts, respectively. CONCLUSIONS: Our study provides a validated equation to accurately predict postoperative new baseline glomerular filtration rate in patients being considered for radical nephrectomy or partial nephrectomy that can be easily implemented in daily clinical practice.

Split renal function in patients with renal masses: utility of parenchymal volume analysis vs nuclear renal scans.

OBJECTIVES: To evaluate the utility of parenchymal volume analysis (PVA) for estimation of split renal function (SRF) in patients with renal masses. SRF is important for deciding about partial vs radical nephrectomy (PN/RN) and assessing risk for developing severe chronic kidney disease after surgery. For renal donors PVA is routinely used to estimate SRF, but the utility of PVA for the more complex renal mass population remains undefined. PATIENTS AND METHODS: All patients (n = 374) with renal tumours and a normal contralateral kidney managed with PN (2010-2018), with preoperative/postoperative nuclear renal scans (NRS) and cross-sectional imaging were analysed. Parenchymal volumes were measured by free-hand scripting or software analysis. Concordance between ipsilateral estimated glomerular filtration rate (eGFR) values based on SRF from NRS vs PVA were evaluated by Pearson correlation and Bland-Altman plots. Parallel analysis of all 155 patients managed with RN at our centre (2006-2016) with preoperative NRS and imaging was also performed. RESULTS: For PN, the median age and tumour size were 62 years and 3.4 cm, respectively. The median preoperative ipsilateral parenchymal volume and eGFR were 181 cm3 and 36.9 mL/min/1.73 m2 , respectively. Parenchymal volumes estimated by free-hand scripting vs software analyses correlated strongly (r = 0.98, P < 0.001). Preoperative ipsilateral eGFR based on SRF from PVA vs NRS also correlated strongly (r = 0.94, P < 0.001). Ipsilateral eGFR saved after PN correlated strongly with parenchymal volume preserved (all r >0.60); however, the correlation was much stronger when ipsilateral eGFRs were based on SRF from PVA rather than NRS (z-statistic = 3.15, P = 0.002). For RN patients, preoperative eGFR in the contralateral kidney based on SRF from PVA vs NRS also correlated strongly (r = 0.87, P < 0.001). CONCLUSION: PVA has utility for estimation of SRF in patients with renal masses, even though this population is older and more comorbid than renal donors and the tumour can complicate the analysis. PVA can be obtained by software analysis from preoperative cross-sectional imaging and thus readily incorporated into routine clinical practice.

Medication Discontinuation Following Transurethral Prostatectomy: an Unrecognized Effectiveness Measure?

PURPOSE OF REVIEW: Freedom from medication is a common goal for patients undergoing surgical treatment of benign prostatic hyperplasia (BPH)/lower urinary tract symptoms (LUTS). Knowing medication discontinuation rates following various forms of transurethral prostatectomy may aid patient counseling and assessing the comparative effectiveness of different approaches. This review examined discontinuation rates of BPH/LUTS medications following transurethral prostatectomy. RECENT FINDINGS: Rates of BPH/LUTS medication use after transurethral resection of the prostate varied from 15% to 55%, and discontinuation rates were 54-95% across medications and follow-up periods. For laser prostatectomy, approximately 18% of patients continued medications postoperatively and discontinuation rates ranged from 53% to 75%. Minimal data on holmium laser enucleation existed. For reference, medication discontinuation rates after transurethral needle ablation or microwave therapy were only 15-28%. No recommendations or best practices inform the use of medical therapy following BPH surgery. Rates of BPH/LUTS medication use following transurethral prostatectomy are considerable.

Poorly functioning kidneys recover from ischemia after partial nephrectomy as well as strongly functioning kidneys.

PURPOSE: Poorly functioning kidneys may not recover from ischemia as well as strongly functioning kidneys. This could impact surgical approaches to partial nephrectomy. MATERIALS AND METHODS: We analyzed the records of 155 consecutive patients treated with partial nephrectomy who underwent appropriate studies to facilitate analysis of function and parenchymal mass in the operated kidney, including computerized tomography and glomerular filtration rate measurement within 2 months preoperatively and 4 to 12 months postoperatively. Patients with a contralateral kidney also underwent renal scan in the same time frame to provide split renal function. Computerized tomography was done to measure functional parenchymal volume before and after partial nephrectomy. Recovery from ischemia, defined as percent glomerular filtration rate saved/percent volume saved, was considered 100% if all nephrons recovered from the ischemic insult. RESULTS: The median R.E.N.A.L. nephrotomy score was 8. Cold ischemia was used in 64 patients and limited warm ischemia was used in 91 (median 27 and 20 minutes, respectively). The median percent glomerular filtration rate saved in the operated kidney was 80% and the median parenchymal volume saved was 83%. The overall median rate of recovery from ischemia was 95%, including 100% for cold ischemia and 92% for limited warm ischemia. Recovery from ischemia was approximately 100% and was similar for all strata of preoperative estimated glomerular filtration rates in the operated kidney (p = 0.24), even in the warm ischemia subgroup. CONCLUSIONS: Our results suggest that the quantity of parenchyma preserved is the main determinant of the postoperative glomerular filtration rate after partial nephrectomy as long as limited warm ischemia or hypothermia is used. Even poorly functioning kidneys recover well from the ischemic insult proportionate to the amount of parenchyma preserved.

Predictors of precision of excision and reconstruction in partial nephrectomy.

PURPOSE: The precision of excision and reconstruction to optimize vascularized parenchymal preservation is a major determinant of renal function after partial nephrectomy. We assessed partial nephrectomy surgical precision using volumetric computerized tomography and analyzed predictive factors. MATERIALS AND METHODS: We analyzed the records of 122 patients treated with partial nephrectomy in whom detailed analysis of the precision of excision and reconstruction specific to the operated kidney could be performed. We used volumetric computerized tomography to measure functional parenchymal volume before and after partial nephrectomy in the operated kidney. The glomerular filtration rate in the operated kidney was determined by the MDRD2 (Modification of Diet in Renal Disease 2) equation along with renal scan in patients with a contralateral kidney. Surgical precision was defined as actual postoperative parenchymal volume/predicted postoperative parenchymal volume, presuming loss of a 5 mm rim of normal parenchyma related to excision and reconstruction. RESULTS: Median patient age was 61 years and 64 patients (52%) underwent an open procedure. Cold ischemia was used in 50 patients (median 26 minutes) and limited warm ischemia (median 20 minutes) was used in 72. The R.E.N.A.L. (radius, exophytic/endophytic, nearness of tumor to collecting system or sinus, anterior/posterior and location relative to polar line) nephrometry score indicated low, intermediate and high complexity in 43 (35%), 55 (45%) and 24 patients (20%), respectively. A total of 45 patients (37%) with a solitary kidney were included in analysis. The median precision of excision and reconstruction was 93%. The median preserved glomerular filtration rate was 80% in the operated kidney. A solitary kidney was the only significant predictor of excision and reconstruction precision on univariable and multivariable analysis. CONCLUSIONS: A solitary kidney significantly impacted partial nephrectomy surgical precision. This was likely related to the recognized need to preserve as much renal parenchyma as possible to optimize renal function in the absence of a contralateral kidney.

Clinical upstaging after neoadjuvant chemotherapy impacting eligibility for vaginal-sparing cystectomy: identifying bladder cancer patients who may benefit from interim imaging.

INTRODUCTION AND OBJECTIVES: Limited data exists on the frequency with which clinical progression during neoadjuvant chemotherapy (NAC) for muscle invasive bladder cancer (MIBC) impacts eligibility for a vaginal-sparing surgical approach or on the utility of interim imaging assessment. We sought to evaluate the incidence of clinical upstaging following NAC that would render a patient ineligible for a vaginal-sparing cystectomy. METHODS: 89 female patients with non-metastatic MIBC treated with NAC and radical cystectomy (RC) (2012-2023) were retrospectively reviewed. Tumor location(s) was determined from transurethral resection of bladder tumor operative reports. Pre- and post-NAC clinical staging was determined from imaging. Outcomes of interest included clinical upstaging and upstaging to vaginal invasion after NAC. RESULTS: 75/89 patients had pre- and post-NAC imaging. 55 had no change in clinical staging, six patients were upstaged (4 cT2→cT3, 2 cT3→cT4), and 14 patients were downstaged (13 cT3→cT2, 1 cT4→cT2). Of the 75 patients with pre- and post-NAC imaging, 39 had trigone tumors. Of these, 28 had no change in clinical staging, two were upstaged (1 cT2→cT3, 1 cT3→cT4) and nine were downstaged (8 cT3→cT2, 1 cT4→cT2). Overall, 6/75 (8%) of patients demonstrated clinical upstaging after NAC. 2/39 (5%) of patients with trigone tumors clinically progressed after NAC and both had vaginal invasion (pT4) on final pathology. CONCLUSIONS: Although clinical upstaging after NAC was infrequent, 5% of patients with trigonal MIBC were rendered ineligible for vaginal-sparing cystectomy following NAC due to progression. Interim imaging assessment may identify non-responders and preserve eligibility for vaginal-sparing RC.

An exploratory study investigating the impact of the bladder tumor microbiome on Bacillus Calmette Guerin (BCG) response in non-muscle invasive bladder cancer.

PURPOSE: Intravesical Bacillus Calmette-Guerin (BCG) is standard of care for intermediate- and high-risk non-muscle invasive bladder cancer (NMIBC). The effect of the bladder microbiome on response to BCG is unclear. We sought to characterize the microbiome of bladder tumors in BCG-responders and non-responders and identify potential mechanisms that drive treatment response. MATERIALS AND METHODS: Patients with archival pre-treatment biopsy samples (2012-2018) were identified retrospectively. Prospectively, urine and fresh tumor samples were collected from individuals with high-risk NMIBC (2020-2023). BCG response was defined as tumor-free 2 years from induction therapy. Extracted DNA was sequenced for 16S rRNA and shotgun metagenomics. Primary outcomes were species richness (α-diversity) and microbial composition (ß-diversity). Paired t-tests were performed for α-diversity (Observed species/Margalef). Statistical analysis for ß-diversity (weighted and unweighted UniFrac distances, weighted Bray-Curtis dissimilarity) were conducted through Permanova, with 999 permutations. RESULTS: Microbial species richness (P < 0.001) and composition (P = 0.001) differed between BCG responders and non-responders. Lactobacillus spp. were significantly enriched in BCG-responders. Shotgun metagenomics identified possible mechanistic pathways such as assimilatory sulfate reduction. CONCLUSION: A compositional difference exists in the tumor microbiome of BCG responders and non-responders with Lactobacillus having increased abundance in BCG responders.

Impact of pathologic re-review on grade, clinical stage, and risk stratification for patients with nonmuscle invasive bladder cancer.

OBJECTIVES: Pathologic re-review of transurethral resection of bladder tumor (TURBT) specimen is a common practice at our tertiary care center, but its impact on disease risk stratification remains unknown. We sought to determine how pathologic re-review of specimen initially read at an outside institution changed grade, clinical T (cT) stage, and AUA non-muscle-invasive bladder cancer (NMIBC) risk stratification. METHODS AND MATERIALS: The laboratory information system was searched for patients who underwent TURBT from 2021 to 2022, yielding 561 records. 173 patients met inclusion criteria: 113 with

Oncologic outcomes of intravesical therapy in the management of nonmuscle invasive bladder cancer with variant histology.

PURPOSE: There is limited data on oncologic outcomes in nonmuscle invasive bladder cancer (NMIBC) with variant histology (VH) managed with intravesical therapy. We sought to evaluate oncologic outcomes for this cohort at a high-volume center. MATERIALS AND METHODS: A retrospective review of an IRB-approved bladder cancer database was performed. Patients with a history of NMIBC with VH present on transurethral resection of bladder tumor (TURBT) treated with intravesical therapy (BCG or chemotherapy) were identified. Outcomes of interest included recurrence within the bladder, progression to muscle-invasive bladder cancer (MIBC), metastatic progression, cancer-specific, and overall survival. Survival time was computed from the date of initiation of intravesical therapy to the date of event or censoring. For patients who underwent radical cystectomy, recurrence-free, cancer-specific, and overall survival were also computed. The Kaplan-Meier method with log rank was utilized to compare survival time between VH sub-groups. RESULTS: Ninety patients were included in the final cohort with a median follow-up of 38 months. The majority of patients had T1 disease (72%) and received intravesical BCG (83%) as their only form of intravesical therapy. The most commonly represented VH in this series were glandular and squamous differentiation (26%). Forty-eight patients (53%) experienced recurrence within the bladder with a median recurrence-free survival of 24 months (95% Confidence Interval [CI]: 2-46 months). Five-year rates of progression to MIBC and distant metastasis were both 14% respectively. Twenty-six patients (28%) eventually required cystectomy. When stratifying by VH, patients with sarcomatoid, plasmacytoid, and micropapillary had significantly worse oncologic outcomes. CONCLUSION: In this series of highly-selected patients with NMIBC and VH, bladder-sparing treatment with intravesical therapy demonstrated acceptable oncologic outcomes for most VHs. This may be an acceptable treatment option for patients without plasmacytoid, sarcomatoid, or micropapillary features who are not suitable cystectomy candidates or who prioritize bladder-sparing treatment.

Impact of Neoadjuvant Chemotherapy on Pathologic Downstaging in Patients With Variant Histology Undergoing Radical Cystectomy.

INTRODUCTION: Variant histology (VH) bladder cancer is often associated with poor outcomes and the role of neoadjuvant chemotherapy (NAC) remains incompletely defined. Our objective was to determine comparative pathologic downstaging at radical cystectomy (RC) following NAC for patients with and without VH. PATIENTS AND METHODS: Patients who underwent RC at 2 tertiary referral centers (1996-2018) were included. Patients with VH (sarcomatoid, nested, micropapillary, plasmacytoid) were matched 1:2 to patients with pure urothelial carcinoma by age, sex, clinical T (cT)stage, clinical N (cN)stage, cystectomy year and receipt of NAC. The primary outcome was pathologic downstaging (pT-stage < cT-stage). The differential impact of NAC on pathologic downstaging between VH and non-VH was assessed using multivariable logistic regression with interaction analysis. RESULTS: 225 VH and 437 non-VH patients were included. One hundred twenty-eight of six hundred sixty-two (19.3%) patients experienced downstaging, including 54/121 (44.6%) patients who received NAC and 74/542 (13.2%) patients who did not (P < .01). Rates of downstaging after NAC for subgroups were: 45/78 (57.7%) urothelial, 3/8 (37.5%) sarcomatoid, 2/12 (16.7%) nested, 3/14 (21.4%) micropapillary, and 1/8 (12.5%) plasmacytoid. Collectively, 9/42 (21.4%) of VH patients who received NAC were downstaged. On multivariable analyses, NAC was associated with increased likelihood of downstaging in the overall cohort (OR 5.25, 95% CI, 3.29-8.36, P < .0001) and this effect was not modified by VH versus non-VH histology (P = .13 for interaction). VH patients had worse survival outcomes compared to non-VH (P < 0.01 for all). CONCLUSION: When comparing patients with VH to matched pure urothelial carcinoma controls, VH did not have an adverse effect on downstaging following NAC. VH patients should not be excluded from NAC if otherwise eligible.

Parenchymal obliteration by renal masses: Functional and oncologic implications.

OBJECTIVES: Most renal tumors merely displace nephrons while others can obliterate parenchyma in an invasive manner. Substantial parenchymal volume replacement (PVR) by renal cell carcinoma (RCC) may have oncologic implications; however, studies regarding PVR remain limited. Our objective was to evaluate the oncologic implications associated with PVR using improved methodology including more accurate and objective tools. PATIENTS/METHODS: A total of 1,222 patients with non-metastatic renal tumors managed with partial nephrectomy (PN) or radical nephrectomy (RN) at Cleveland Clinic (2011-2014) with necessary studies were retrospectively evaluated. Parenchymal volume analysis via semiautomated software was used to estimate split renal function and preoperative parenchymal volumes. Using the contralateral kidney as a control, %PVR was defined: (parenchymal volumecontralateral-parenchymal volumeipsilateral) normalized by parenchymal volumecontralateral x100%. PVR was determined preoperatively and not altered by management. Patients were grouped by degree of PVR: minimal (<5%, N = 566), modest (5%-25%, N = 414), and prominent (≥25%, N = 142). Kaplan-Meier was used to evaluate survival outcomes relative to degree of PVR. Multivariable Cox-regression models evaluated predictors of recurrence-free survival (RFS). RESULTS: Of 1,122 patients, 801 (71%) were selected for PN and 321 (29%) for RN. Overall, median tumor size was 3.1 cm and 6.8 cm for PN and RN, respectively, and median follow-up was 8.6 years. Median %PVR was 15% (IQR = 6%-29%) for patients selected for RN and negligible for those selected for PN. %PVR correlated inversely with preoperative ipsilateral GFR (r = -0.49, P < 0.01) and directly with advanced pathologic stage, high tumor grade, clear cell histology, and sarcomatoid features (all P < 0.01). PVR≥25% associated with shortened recurrence-free, cancer-specific, and overall survival (all P < 0.01). Male sex, ≥pT3a, tumor grade 4, positive surgical margins, and PVR≥25% independently associated with reduced RFS (all P < 0.02). CONCLUSIONS: Obliteration of normal parenchyma by RCC substantially impacts preoperative renal function and patient selection. Our data suggests that increased PVR is primarily driven by aggressive tumor characteristics and independently associates with reduced RFS, although further studies will be needed to substantiate our findings.

Functional recovery after partial nephrectomy in a solitary kidney.

OBJECTIVES: Partial nephrectomy (PN) is the reference standard for renal mass in a solitary kidney (RMSK), although factors determining functional recovery in this setting remain poorly defined. PATIENTS/METHODS: Single center, retrospective analysis of 841 RMSK patients (1975-2022) managed with PN with functional data, including 361/435/45 with cold/warm/zero ischemia, respectively. A total of 155 of these patients also had necessary studies for detailed analysis of parenchymal volume preserved. Acute kidney injury (AKI) was classified by RIFLE (Risk/Injury/Failure/Loss/Endstage). Recovery-from-ischemia (Rec-Ischemia) was defined as glomerular filtration rate (GFR) saved normalized by parenchymal volume saved. Logistic regression identified predictive factors for AKI and predictors of Rec-Ischemia were analyzed by multivariable linear regression. RESULTS: Overall, median preoperative GFR was 56.7 ml/min/1.73m2 and new-baseline and 5-year GFRs were 43.1 and 44.5 ml/min/1.73m2, respectively. Median follow-up was 55 months; 5-year dialysis-free survival was 97%. In the detailed analysis cohort, a primary focus of this study, median warm (n = 70)/cold (n = 85) ischemia times were 25/34 minutes, respectively; and median preoperative, new-baseline and 5-year GFRs were 57.8, 45.0, and 41.7 ml/min/1.73m2, respectively. Functional recovery correlated strongly with parenchymal volume preserved (r = 0.84, p < 0.001). Parenchymal volume loss accounted for 69% of the total median GFR decline associated with PN, leaving only 3 to 4 ml/min/1.73m2 attributed to ischemia and other factors. AKI occurred in 52% of patients and the only independent predictor of AKI was ischemia time. Independent predictors of reduced Rec-Ischemia were increased age, warm ischemia, and AKI. CONCLUSION: The main determinant of functional recovery after PN in RMSK is parenchymal volume preservation. Type/duration of ischemia, AKI, and age also correlated, although altogether their contributions were less impactful. Our findings suggest multiple opportunities for optimizing functional outcomes although preservation of parenchymal volume remains predominant. Long-term function generally remains stable with dialysis only occasionally required.