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.

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.

Reducing False-Positives Due to Urinary Stagnation in the Prostatic Urethra on 18 F-DCFPyL PSMA PET/CT With MRI

PURPOSE

Prostate-specific membrane antigen (PSMA)-targeting PET radiotracers reveal physiologic uptake in the urinary system, potentially misrepresenting activity in the prostatic urethra as an intraprostatic lesion. This study examined the correlation between midline 18 F-DCFPyL activity in the prostate and hyperintensity on T2-weighted (T2W) MRI as an indication of retained urine in the prostatic urethra.

PATIENTS AND METHODS

Eighty-five patients who underwent both 18 F-DCFPyL PSMA PET/CT and prostate MRI between July 2017 and September 2023 were retrospectively analyzed for midline radiotracer activity and retained urine on postvoid T2W MRIs. Fisher's exact tests and unpaired t tests were used to compare residual urine presence and prostatic urethra measurements between patients with and without midline radiotracer activity. The influence of anatomical factors including prostate volume and urethral curvature on urinary stagnation was also explored.

RESULTS

Midline activity on PSMA PET imaging was seen in 14 patients included in the case group, whereas the remaining 71 with no midline activity constituted the control group. A total of 71.4% (10/14) and 29.6% (21/71) of patients in the case and control groups had urethral hyperintensity on T2W MRI, respectively ( P < 0.01). Patients in the case group had significantly larger mean urethral dimensions, larger prostate volumes, and higher incidence of severe urethral curvature compared with the controls.

CONCLUSIONS

Stagnated urine within the prostatic urethra is a potential confounding factor on PSMA PET scans. Integrating PET imaging with T2W MRI can mitigate false-positive calls, especially as PSMA PET/CT continues to gain traction in diagnosing localized prostate cancer.

Limitations of Parenchymal Volume Analysis for Estimating Split Renal Function and New Baseline Glomerular Filtration Rate After Radical Nephrectomy

PURPOSE

Accurately predicting new baseline glomerular filtration rate (NBGFR) after radical nephrectomy (RN) can improve counseling about RN vs partial nephrectomy. Split renal function (SRF)-based models are optimal, and differential parenchymal volume analysis (PVA) is more accurate than nuclear renal scans (NRS) for this purpose. However, there are minimal data regarding the limitations of PVA. Our objective was to identify patient-/tumor-related factors associated with PVA inaccuracy.

MATERIALS AND METHODS

Five hundred and ninety-eight RN patients (2006-2021) with preoperative CT/MRI were retrospectively analyzed, with 235 also having NRS. Our SRF-based model to predict NBGFR was: 1.25 × (GlobalGFRPre-RN × SRFContralateral), where GFR indicates glomerular filtration rate, with SRF determined by PVA or NRS, and with 1.25 representing the median renal functional compensation in adults. Accuracy of predicted NBGFR within 15% of observed was evaluated in various patient/tumor cohorts using multivariable logistic regression analysis.

RESULTS

PVA and NRS accuracy were 73%/52% overall, and 71%/52% in patients with both studies (n = 235, P < .001), respectively. PVA inaccuracy independently associated with pyelonephritis, hydronephrosis, renal vein thrombosis, and infiltrative features (all P < .03). Ipsilateral hydronephrosis and renal vein thrombosis associated with PVA underprediction, while contralateral hydronephrosis and increased age associated with PVA overprediction (all P < .01). NRS inaccuracy was more common and did not associate with any of these conditions. Even among cohorts where PVA inaccuracy was observed (22% of our patients), there was no significant difference in the accuracies of NRS- and PVA-based predictions.

CONCLUSIONS

PVA was more accurate for predicting NBGFR after RN than NRS. Inaccuracy of PVA correlated with factors that distort the parenchymal volume/function relationship or alter renal functional compensation. NRS inaccuracy was more common and unpredictable, likely reflecting the inherent inaccuracy of NRS. Awareness of cohorts where PVA is less accurate can help guide clinical decision-making.

PADRES: a phase 2 clinical trial of neoadjuvant axitinib for complex partial nephrectomy

OBJECTIVE

To report the results of PADRES (Prior Axitinib as a Determinant of Outcome of Renal Surgery, NCT03438708), a study investigating neoadjuvant axitinib for tumours of high complexity with imperative indication for partial nephrectomy (PN).

METHODS

We conducted a single-arm phase II clinical trial of localized (cT1b-cT3M0) clear-cell renal cell carcinoma (RCC) patients with imperative indications for nephron preservation, where PN is a high-risk procedure due to complexity (RENAL score 10-12). Axitinib 5 mg was administered twice daily for 8 weeks with repeat imaging at completion, followed by surgery. The primary outcome was successful completion of planned PN following axitinib treatment. Secondary objectives included changes in tumour diameter, RENAL nephrometry score, renal function and Response Evaluation Criteria in Solid Tumours (RECIST) v1.1, and surgical complications.

RESULTS

Twenty-seven patients were enrolled (median age 69 years). Prior to therapy, twenty patients (74.0%) had ≥ clinical T3a staged tumours. Axitinib resulted in reductions in tumour diameter (7.5 vs 6.2 cm; P < 0.001) and RENAL score (11 vs 10; P < 0.001). Nine patients (33.3%) had partial response based on RECIST and nine (33.3%) were clinically downstaged. PN was performed in twenty patients (74.0%); twenty-five patients (96.2%) had negative margins. Six patients (22.2%) had Clavien III-IV complications. The median change in estimated glomerular filtration rate (preoperative to last follow-up) was 8.5 mL/min/1.73 m2 .

CONCLUSION

Neoadjuvant axitnib resulted in reductions in tumour size and complexity, enabling safe and feasible PN and functional preservation in patients with complex renal masses and imperative indication.

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.

Practical Prediction of New Baseline Renal Function After Partial Nephrectomy

BACKGROUND

Partial nephrectomy (PN) is generally preferred for localized renal masses due to strong functional outcomes. Accurate prediction of new baseline glomerular filtration rate (NBGFR) after PN may facilitate preoperative counseling because NBGFR may affect long-term survival, particularly for patients with preoperative chronic kidney disease. Methods for predicting parenchymal volume preservation, and by extension NBGFR, have been proposed, including those based on contact surface area (CSA) or direct measurement of tissue likely to be excised/devascularized during PN. We previously reported that presuming 89% of global GFR preservation (the median value saved from previous, independent analyses) is as accurate as the more subjective/labor-intensive CSA and direct measurement approaches. More recently, several promising complex/multivariable predictive algorithms have been published, which typically include tumor, patient, and surgical factors. In this study, we compare our conceptually simple approach (NBGFRPost-PN = 0.90 × GFRPre-PN) with these sophisticated algorithms, presuming that an even 90% of the global GFR is saved with each PN.

PATIENTS AND METHODS

A total of 631 patients with bilateral kidneys who underwent PN at Cleveland Clinic (2012-2014) for localized renal masses with available preoperative/postoperative GFR were analyzed. NBGFR was defined as the final GFR 3-12 months post-PN. Predictive accuracies were assessed from correlation coefficients (r) and mean squared errors (MSE).

RESULTS

Our conceptually simple approach based on uniform 90% functional preservation had equivalent r values when compared with complex, multivariable models, and had the lowest degree of error when predicting NBGFR post-PN.

CONCLUSIONS

Our simple formula performs equally well as complex algorithms when predicting NBGFR after PN. Strong anchoring by preoperative GFR and minimal functional loss (≈ 10%) with the typical PN likely account for these observations. This formula is practical and can facilitate counseling about expected postoperative functional outcomes after PN.

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.

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.

Selective Use of Neoadjuvant Targeted Therapy Is Associated with Greater Achievement of Partial Nephrectomy for High-complexity Renal Masses in a Solitary Kidney

Background

Partial nephrectomy (PN) is preferred for a renal mass in a solitary kidney (RMSK), although tumors with high complexity can be challenging.

Objective

To evaluate the evolution of RMSK management with a focus on achievement of PN.

Design setting and participants

Patients with nonmetastatic RMSK (n = 499) were retrospectively reviewed; 133 had high tumor complexity, including 80 in the pre-tyrosine kinase inhibitor (TKI) era (1999-2008) and 53 in the TKI era (2009-2022). After 2009, 23/53 patients received neoadjuvant TKI and 30/53 had immediate-surgery.

Outcome measurements and statistical analysis

Functional outcomes, adverse events and complications, dialysis-free survival, and recurrence-free survival (RFS) were the measures evaluated. Mann-Whitney and χ2 tests were used to compare cohorts, and the log-rank test was applied for survival analyses.

Results and limitations

Overall, the median RENAL score was 10 and the median tumor diameter was 5.2 cm. Demographic characteristics, tumor diameter, and RENAL scores were similar between the pre-TKI-era and TKI-era groups. In the TKI era, 23/53 patients (43%) with clear-cell histology were selected for neoadjuvant TKI. These 23 patients had a greater median tumor diameter (7.1 vs 4.4 cm; p = 0.02) and RENAL score (11 vs 10; p = 0.07). After TKI treatment, the median tumor diameter decreased to 5.6 cm and the RENAL score to 9, and tumor volume was reduced by 59% (all p < 0.05). PN was accomplished in 21/23 (91%) the TKI-treated cases and in 27/30 (90%) of the immediate-surgery cases (2009-2022). PN was only accomplished in 52/80 (65%) of the patients from the pre-TKI era (p < 0.01). The 5-yr dialysis-free survival rate was 59% in the pre-TKI-era group and 91% in the TKI-era group. The 5-yr RFS rate was lower in the TKI-era group (59% vs 74%; p = 0.21), which was mostly related to more aggressive tumor biology, as reflected by a predominance of systemic rather than local recurrences.

Conclusions

Management of RMSK with high tumor complexity is challenging. Selective use of TKI therapy was associated with greater use of PN, although a randomized study is needed. RFS mostly reflected aggressive tumor biology rather than failure of local management.

Patient summary

For complex kidney tumors in patients with a single kidney, management is challenging. Use of drugs called tyrosine kinase inhibitors before surgery was associated with reductions in tumor size and greater ability to achieve partial kidney removal for cancer control. Most recurrences were metastatic, which reflects aggressive tumor biology rather than failure of surgery.

Metastatic renal cell carcinoma to the pancreas and other sites-a multicenter retrospective study

Background

Metastatic renal cell carcinoma (mRCC) is a heterogenous disease with poor 5-year overall survival (OS) at 14%. Patients with mRCC to endocrine organs historically have prolonged OS. Pancreatic metastases are uncommon overall, with mRCC being the most common etiology of pancreatic metastases. In this study, we report the long-term outcomes of patients with mRCC to the pancreas in two separate cohorts.

Methods

We performed a multicenter, international retrospective cohort study of patients with mRCC to the pancreas at 15 academic centers. Cohort 1 included 91 patients with oligometastatic disease to the pancreas. Cohort 2 included 229 patients with multiples organ sites of metastases including the pancreas. The primary endpoint for Cohorts 1 and 2 was median OS from time of metastatic disease in the pancreas until death or last follow up.

Findings

In Cohort 1, the median OS (mOS) was 121 months with a median follow up time of 42 months. Patients who underwent surgical resection of oligometastatic disease had mOS of 100 months with a median follow-up time of 52.5 months. The mOS for patients treated with systemic therapy was not reached. In Cohort 2, the mOS was 90.77 months. Patients treated with first-line (1L) VEGFR therapy had mOS of 90.77 months; patients treated with IL immunotherapy (IO) had mOS of 92 months; patients on 1L combination VEGFR/IO had mOS of 74.9 months.

Interpretations

This is the largest retrospective cohort of mRCC involving the pancreas. We confirmed the previously reported long-term outcomes in patients with oligometastatic pancreas disease and demonstrated prolonged survival in patients with multiple RCC metastases that included the pancreas. In this retrospective study with heterogeneous population treated over 2 decades, mOS was similar when stratified by first-line therapy. Future research will be needed to determine whether mRCC patients with pancreatic metastases require a different initial treatment strategy.

Funding

Statistical analyses for this study were supported in part by the University of Colorado Cancer Center Support Grant from the NIH/NCI, P30CA046934-30.

Long-Term Renal Function Following Renal Cancer Surgery: Historical Perspectives, Current Status, and Future Considerations

Knowledge of functional recovery after partial (PN) and radical nephrectomy for renal cancer has advanced considerably, with PN now established as the reference standard for most localized renal masses. However, it is still unclear whether PN provides an overall survival benefit in patients with a normal contralateral kidney. While early studies seemingly demonstrated the importance of minimizing warm-ischemia time during PN, multiple new investigations over the last 10 years have proven that parenchymal mass lost is the most important predictor of new baseline renal function. Minimizing loss of parenchymal mass during resection and reconstruction is the most important controllable aspect of long-term post-operative renal function preservation.

Point of care parenchymal volume analyses to estimate split renal function and predict functional outcomes after radical nephrectomy

Accurate prediction of new baseline GFR (NBGFR) after radical nephrectomy (RN) can inform clinical management and patient counseling whenever RN is a strong consideration. Preoperative global GFR, split renal function (SRF), and renal functional compensation (RFC) are fundamentally important for the accurate prediction of NBGFR post-RN. While SRF has traditionally been obtained from nuclear renal scans (NRS), differential parenchymal volume analysis (PVA) via software analysis may be more accurate. A simplified approach to estimate parenchymal volumes and SRF based on length/width/height measurements (LWH) has also been proposed. We compare the accuracies of these three methods for determining SRF, and, by extension, predicting NBGFR after RN. All 235 renal cancer patients managed with RN (2006-2021) with available preoperative CT/MRI and NRS, and relevant functional data were analyzed. PVA was performed on CT/MRI using semi-automated software, and LWH measurements were obtained from CT/MRI images. RFC was presumed to be 25%, and thus: Predicted NBGFR = 1.25 × Global GFRPre-RN × SRFContralateral. Predictive accuracies were assessed by mean squared error (MSE) and correlation coefficients (r). The r values for the LWH/NRS/software-derived PVA approaches were 0.72/0.71/0.86, respectively (p < 0.05). The PVA-based approach also had the most favorable MSE, which were 120/126/65, respectively (p < 0.05). Our data show that software-derived PVA provides more accurate and precise SRF estimations and predictions of NBGFR post-RN than NRS/LWH methods. Furthermore, the LWH approach is equivalent to NRS, precluding the need for NRS in most patients.

Phase II study of axitinib prior to partial nephrectomy to preserve renal function: An interim analysis of the PADRES clinical trial

683

Background: In renal cell carcinoma (RCC), partial nephrectomy (PN) is indicated for patients with solitary kidney, chronic kidney disease, or bilateral tumors. A subset of these patients, however, may have large and complex renal masses not initially suitable for PN. Neoadjuvant Tyrosine Kinase Inhibitor therapy has shown promising results in cytoreducing renal tumors and may permit PN in circumstances not otherwise feasible. Methods: This was a single arm phase II clinical trial of neoadjuvant axitinib in patients with complex (RENAL nephrometry score 10-12 and cT1b-cT3M0) biopsy-proven clear cell RCC with strong indications for partial nephrectomy (PN), and in whom radical nephrectomy may result in dialysis dependence. Axitinib 5 mg was administered orally twice daily for 8 weeks prior to surgery. Primary outcome was reduction in longest tumor diameter; secondary outcomes included tumor response (RECIST), change in RENAL score, feasibility of PN, change in estimated glomerular filtration rate (DeGFR), and post-surgical complications. Results: 26 patients were enrolled. 19 (73.1%) patients had ≥ clinical T3a staged tumors. Post therapy, 17 (65.4%) patients had ≥T3a staged tumors. Axitinib resulted in reductions in tumor size (7.7 vs. 6.3 cm, p<0.001) and RENAL score (11 vs. 10, p <0.001); 9 (34.6%) had partial response, and 17 (65.4%) stable disease by RECIST criteria. PN was successfully performed in 19 (73.1%); 24 (96.8%) achieved negative margins. Six (23.1%) had Clavien III-IV post-surgical complications. Median percentage DeGFR was 14.7%; one (3.8%) patient who had a radical nephrectomy had long-term dialysis dependence. Conclusions: Neoadjuvant axitnib resulted in significant reductions in tumor size and complexity, enabling PN in a cohort of complex renal masses, and with acceptable safety and functional preservation. Clinical trial information: NCT03438708 . [Table: see text]

BMX inhibition and HSD3B1-driven resistance in prostate cancer in the Maverick trial

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Background: Kinase inhibitors have been ineffective in prostate cancer and have no known role in androgen biosynthesis. Inheritance of the adrenal-permissive HSD3B1(1245C) allele encodes a 3βHSD1 enzyme missense that up-regulates the rate-limiting step of androgen biosynthesis from non-gonadal precursor steroids and confers poor clinical outcomes in castration-resistant prostate cancer (CRPC). About half of all men with prostate cancer inherit the adrenal-permissive HSD3B1 allele. Multiple clinical studies demonstrate that adrenal-permissive HSD3B1 allele inheritance confers more rapid progression on ADT and others also suggest worse CRPC outcomes even after treatment with abiraterone or enzalutamide. However, there is no known method to clinically block 3βHSD1. Furthermore, 3βHSD1 is not known to be phosphorylated. Methods: Mass spectrometry was used to identify protein phosphorylation sites and steroid metabolites, genetic and pharmacologic methods were used to identify the kinase required for 3βHSD1 phosphorylation and mouse xenograft studies were performed with BMX inhibition. The identified mechanism was used to design and launch a multicenter phase 2 study of the BMX inhibitor abivertinib in combination with abiraterone in men with metastatic CRPC. Results: 3βHSD1 enzyme activity requires tyrosine phosphorylation at Y344 by the BMX kinase. Androgen biosynthesis is blocked by a phosphorylation-defective 3βHSD1 344F, or BMX genetic knockdown, or BMX pharmacologic inhibition. BMX inhibition using zanubrutinib suppresses CRPC growth in the C4-2 and VCaP xenograft models by blocking intratumoral androgen synthesis and tumor androgen receptor (AR) signaling. Discovery of this mechanism provides the rationale for the phase 2 Maverick trial of abivertinib, a BMX inhibitor, combined with abiraterone, in men with CRPC with adrenal-permissive HSD3B1 allele inheritance (NCT05361915). Eligibility includes 1) presence of metastatic CRPC, 2) measurable and/or non-measurable disease, and 3) confirmed positivity of adrenal-permissive HSD3B1(1245C) allele inheritance via central testing (cap heterozygosity at 50%). Patients will be enrolled in 2 arms: 1) abiraterone naïve (n=45) and 2) abiraterone progressing (n=55). All patients will receive treatment with abivertinib 200mg twice daily with abiraterone 1000mg daily and prednisone 5mg by mouth twice daily. The primary outcome is 6-month radiographic progression-free survival. On-treatment biopsies will be used to inform mechanisms of response and resistance in patients. Conclusions: BMX is required for 3βHSD1 phosphorylation, androgen biosynthesis and CRPC progression with the adrenal-permissive HSD3B1(1245C) allele. The Maverick trial will test clinical proof-of-concept of BMX inhibition in men with adrenal-permissive HSD3B1(1245C) inheritance. Clinical trial information: NCT05361915 .

Differences in the tumor transcriptomic profile of patients (pts) with advanced prostate cancer (PCa) with and without diabetes mellitus (DM)

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Background: Pre-existing DM is associated with increased PCa specific and all-cause mortality in men with prostate cancer (PMID: 27652121). However, the underlying reasons are unclear. We hypothesized that transcriptomic profile of metastatic PCa pts with diagnosis of DM prior to the diagnosis of metastatic disease and start of systemic therapy will be different from those without DM. Methods: In this IRB-approved retrospective study, advanced PCa pts with available RNA profiling of treatment naïve tumor tissue through a CLIA-certified laboratory were included. Based on pre-existing DM prior to onset of metastatic disease, pts was grouped into DM and non-DM. Differential gene expression analysis between the two groups was performed using DeSeq2. These results were subjected to Gene Set Enrichment software analysis (GSEA) to identify pathways enriched in each cohort. Gene ontology analysis using TopGO software was done to identify the biological process occurring at the molecular level of these differentially expressed genes. All bioinformatic analysis was conducted in R studio, version 4.1.1. Results: 75 pts were eligible and included: 20 DM vs 55 non-DM. Baseline characteristics (DM vs non-DM): median age 63.5 vs 64 years; median PSA at diagnosis 20 vs 18.85ng/mL; de novo disease: 55% vs 43.6%; Gleason score ≥8: 60% vs 74.5%. DM pts had upregulation of the following pathways: TNF alpha signaling, inflammatory response, IL-6 JAK STAT3 signaling, heme metabolism, and the p53 pathway vs non-DM pts. Gene ontology analysis and individual differential gene expression profiles will be reported at the meeting. Conclusions: Our study found that pre-existing DM is associated with upregulation of inflammatory pathways in pts with PCa These hypothesis-generating results need external validation. Identification of transcriptomic biomarkers in these subsets of pts may help with further drug development. [Table: see text]

Accuracy of fully automated, AI-generated models compared with validated clinical model to predict post-operative glomerular filtration rate after renal surgery

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Background: The American Urologic Association (AUA) recommends estimation of the postoperative glomerular filtration rate (GFR) in patients with a renal mass to help decide between partial nephrectomy (PN) or radical nephrectomy (RN). If postoperative GFR<45 mL/min/1.73m2, a PN should be prioritized. Most existing methods to predict postoperative GFR are rarely implemented in the clinical setting due to complexity. Previously validated models based on clinical equations or kidney volumes from hand-segmented or semi-automated segmentations are quite accurate but have seen limited uptake in clinical practice. We hypothesize that we could develop an artificial intelligence (AI)-GFR prediction that would be calculated automatically on a preoperative computed tomography (CT) scan and predict a postoperative GFR as accurately as a validated clinical model. Methods: 300 patients undergoing PN or RN for renal tumor from the 2021Kidney and Kidney Tumor Segmentation Challenge(KiTS21) were analyzed. We excluded 7 patients having bilateral tumors. Preoperative GFR was the closest recorded value preoperatively and postoperative GFR≥90 days postoperatively. Split-renal-function (SRF) was determined in a fully automated way from preoperative imaging and our previously developed deep learning segmentation model. We programmed the algorithm to estimate postoperative GFR as 1.24×preoperative GFR×contralateral SRF for RN; and as 89% of the preoperative GFR for PN. We compared AI-predicted GFR to a validated clinical model (GFR=35+preoperative GFR(x0.65)-18(if radical nephrectomy)-age(x0.25)+3(if tumor size >7 cm)-2 (if diabetes)). We compared the AI and clinical model estimations of GFR to the measured postoperative GFR using correlation coefficients (R) and compared the ability of AI models to predict a postoperative GFR<45 using logistic regression and AUCs. Results: In 293 patients, the median age was 60 years ((IQR) 51-68), 40.6% were female, and 62.1% had PN. The median tumor size was 4.2 (2.6-6.1), and 91.8% of the tumors were malignant, of which 35.1% were high-grade, 25.6% were high-stage, and 21.8% had necrosis. The median R.E.N.A.L. nephrometry score was 8 (7-9). When comparing measured postoperative GFR, the correlation coefficients were 0.75 and 0.77 for the AI model and clinical models, respectively. For the prediction of a postoperative GFR< 45 ml/min/1.73m2, the AI and clinical models performed similarly (AUC of 0.89 and 0.9, respectively). Conclusions: Our study demonstrates the feasibility of a fully automated prediction of postoperative GFR based on CT imaging and baseline GFR with comparable predictive accuracy to existing validated clinical prediction models. These AI-generated predictions can be implemented for decision-making, with no clinical details, clinician time, or measurements needed.

Correlation of tumor gene expression profile and gleason score (GS) in patients (pts) with metastatic prostate cancer

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Background: GS is the most powerful prognostic predictor in prostate adenocarcinoma. However, the underlying reasons of disease aggressiveness as a function of GS are currently unknown. Herein we sought to investigate the corresponding differences in gene expression profiles of pts with prostate adenocarcinoma with respect to GS. Methods: In this IRB approved retrospective study, eligibility criteria included histologically confirmed prostate adenocarcinoma and available RNA sequencing results from treatment naïve primary prostate tissue by a CLIA certified lab. Pts were categorized into two cohorts: low GS (GS <8) and high GS (GS ≥ 8). The DEseq2 pipeline was used to analyze differentially expressed genes between the groups. The data included the Log2 fold change, Wald-Test p-values, and Benjamini-Hochberg adjusted p-values for each differentially expressed gene. These results were subjected to Gene Set Enrichment software analysis (GSEA) in order to identify pathways enriched in each cohort. All bioinformatic analyses were undertaken using R v4.2. Results: Fifty-seven pts were eligible, of which 13 had a GS <8 and 44 had a GS ≥8. Tumor tissues with high GS had a significantly higher expression of genes involved in the immune pathways (e.g., inflammatory response, interferon-γ, allograft rejection, and interferon-α), epithelial-mesenchymal transition, KRAS signaling, E2F targets and G2M checkpoint (q for all <0.01). The genes involved in the androgen response pathway were significantly more expressed in biopsies with a low GS (q<0.01). Normalized enrichment scores are reported in the table. Differential individual gene expression profiles will be presented at the meeting. Conclusions: Pts with prostatic adenocarcinoma with a GS ≥8 demonstrated a different transcriptomic profile than those with a GS <8. Higher GS tumor tissues had upregulated of inflammatory, proliferation, and KRAS signaling. Lower GS tumor tissues had upregulated androgen signaling pathway. These hypothesis-generating results upon external validation may provide the rationale for personalized therapy in men with prostatic cancer. [Table: see text]

Comprehensive Management of Renal Masses in Solitary Kidneys

BACKGROUND

A renal mass in a solitary kidney (RMSK) has traditionally been managed with partial nephrectomy (PN), although radical nephrectomy (RN) is occasionally required. Most RMSK studies have focused on patients for whom PN was achieved.

OBJECTIVE

To provide a comprehensive analysis of the management strategies/outcomes for an RMSK and address knowledge deficits regarding this challenging disorder.

DESIGN, SETTING, AND PARTICIPANTS

A total of 1024 patients diagnosed with an RMSK (1975-2022) were retrospectively evaluated. Baseline characteristics and pathologic/functional/survival outcomes were analyzed.

INTERVENTION

PN/RN/cryoablation (CA)/active surveillance (AS).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Functional outcomes, perioperative morbidity/mortality, and 5-yr recurrence-free survival (RFS) were evaluated. Kruskal-Wallis and chi-square tests were used to compare cohorts, and log-rank test and Cox proportional hazard model were used for survival analysis.

RESULTS AND LIMITATIONS

Of 1024 patients, 842 underwent PN (82%), 102 CA (10%), 54 RN (5%), and 26 AS (3%). The median tumor size and RENAL([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) score were 3.7 cm and 8, respectively. The median follow-up was 53 mo. For PN, 95% were clamped, and the median warm and cold ischemia times were 22 and 45 min, respectively. For PN, the median preoperative glomerular filtration rate (GFR) was 57 ml/min/1.73 m², and the median new baseline and 5-yr GFRs were 47 and 48 ml/min/1.73 m², respectively. Dialysis-free survival for PN was 97% at 5 yr. Twenty-two (2.1%) patients with clear-cell renal cell carcinoma and RENAL score ≥10 (median = 11) received tyrosine kinase inhibitors (TKIs) to facilitate PN, leading to 57% median decrease of tumor volume; PN was accomplished in 20 (91%). Forty-one patients had planned RN (4.0%), most often due to severe pre-existing chronic kidney disease (CKD), and 13 were converted from PN to RN (1.5%). Clavien III-V perioperative complications were observed in 80 (8%) patients and 90-d mortality was 0.6%. Five-year RFS for PN, CA, and RN were 83%, 80%, and 72%, respectively (p = 0.03 for PN vs RN).

CONCLUSIONS

Nephron-sparing approaches are feasible and successful in most RMSK patients. PN for an RMSK is often challenging but can be facilitated by selective use of TKIs. RN is occasionally required due to severe CKD, over-riding oncologic concerns, or conversion from PN. This is the first large RMSK study to provide a comprehensive analysis of all management strategies/outcomes.

PATIENT SUMMARY

Kidney cancer in a solitary kidney is a major challenge for achieving cancer-free status and avoiding dialysis. Although partial nephrectomy is the principal treatment for a renal mass in a solitary kidney, other options are occasionally required to optimize outcomes.