Analysis of survival for patients with chronic kidney disease primarily related to renal cancer surgery

Scoring system for prediction of overall survival in patients with renal cell carcinoma T3aN0M0

Objective

We aim to create a new score to predict postoperative overall survival in patients with nonmetastatic T3aN0 renal cell carcinoma.

Methods

We reviewed the clinical data of adult patients who underwent radical nephrectomy for renal cell carcinoma between December 2007 and January 2022 in a single tertiary oncological institution. Clinical characteristics, clinical-pathological staging and histopathological characteristics were analysed. Survival analyses were determined using the Kaplan-Meier curve. A nomogram was established using Cox proportional hazard regression to identify the prognostic factors affecting the overall survival. The area under the curve, calibration curves and decision curve analysis were used to evaluate prognostic efficacy.

Results

We analyzed 362 patients classified as pT3aN0M0 stage with a median follow-up of 40 months. According to Cox univariate and multivariate analyses, weight loss greater than 5% in 6 months before surgery, stage V chronic kidney disease after radical nephrectomy, sarcomatoid pattern, and coagulative tumor necrosis were identified as predictors of overall survival. We developed a score and performed internal and external validation. The time-dependent receiver operating characteristic curve, area under the curve value and calibration curve analysis showed good prediction ability of the score. The nomogram can effectively predict and stratify overall survival after radical nephrectomy in patients with pT3aN0M0 renal cell carcinoma.

Conclusion

Patients with pT3aN0MO renal cell carcinoma exhibited different characteristics, and those with unfavourable characteristics deserve greater attention during follow-up. This nomogram provides an accurate prediction of overall survival after radical nephrectomy.

Incidence, risk factors, and significance of 20% decrease from new baseline estimated glomerular filtration rate after radical and partial nephrectomy within 2 years

OBJECTIVES

To evaluate the incidence and risk factors of a 20% decrease from new baseline (NB)-estimated glomerular filtration rate (eGFR) within 2 years after radical nephrectomy (RN) and partial nephrectomy (PN) and to examine the difference in the incidence of end-stage renal disease (ESRD) with or without the 20% decrease.

METHODS

This retrospective study included 238 patients undergoing RN and 369 undergoing PN for cT1a-cT3a renal cancer. The incidence of a 20% decrease from NB-eGFR within 2 years after RN/PN was examined and its potential risk factors including surgery type were assessed by multivariate logistic regression analysis. The development of ESRD was analyzed as an endpoint and its incidence was compared according to the presence or absence of the 20% decrease from NB-eGFR within 2 years.

RESULTS

Overall, the 20% decrease from NB-eGFR within 2 years was observed in 37 patients (6.1%), including 10 (4.2%) and 27 (7.3%) after RN and PN, respectively (p = 0.117). Diabetes mellitus, proteinuria, and perioperative complications were shown to be independent risk factors for the 20% decrease from NB-eGFR, while surgery type was not. During the median follow-up of 65 months, the ESRD-free survival rate at 6 years was 75.5% and 99.6% in patients with and without the 20% decrease from NB-eGFR, respectively (p < 0.001), while no significant difference was observed between patients undergoing RN and PN (98.1% and 98.7%, p = 0.561).

CONCLUSIONS

Because the incidence of ESRD after the 20% decrease from NB-eGFR within 2 years was as high as 24.5% at 6 years, these patients should be followed with utmost care.

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.

Predicting new-baseline glomerular filtration rate (NBGFR) after donor nephrectomy: validation of a split renal function (SRF)-based formula

BACKGROUND

Accurate prediction of post-donor nephrectomy (DN) glomerular filtration rate is potentially useful for evaluating and counselling living kidney donors. Currently, there are limited tools to evaluate post-operative new-baseline glomerular filtration rate (NBGFR) in kidney donors. We aim to validate a conceptually simple formula based on split renal function (SRF) previously developed for radical nephrectomy patients.

METHODS

Eighty-three consecutive patients who underwent DN from 2010 to 2016 were included. Pre-operative CT imaging and functional data including pre-DN baseline Global GFR (108.2 ± 13.2 mL/min/1.73m2) were included. Observed NBGFR was defined as the latest eGFR 3-12 months post-DN. SRF, defined as volume of the contralateral non-resected kidney normalised by total volume of kidneys, was determined from pre-operative cross-sectional imaging (49.2 ± 2.36%). The equation derived from Rathi et al. is as detailed: Predicted NBGFR = 1.24 × (Global GFR Pre-DN) x (SRF).

RESULTS

The relationship between predicted NBGFR (66.0 ± 8.29 mL/min/1.73m2) and observed NBGFR (74.9 ± 16.4 mL/min/1.73m2) was assessed by evaluating correlation coefficients, bias, precision, accuracy, and concordance. The new SRF-based formula for NBGFR prediction correlated strongly with observed post-operative NBGFR (Pearson's r = 0.729) demonstrating minimal bias (median difference = 7.190 mL/min/1.73m2) with good accuracy (96.4% within ± 30%, 62.7% within ± 15%) and precision (IQR of bias =  - 0.094 to 16.227).

CONCLUSION

The SRF-based formula was also able to accurately discriminate all but one patient to an NBGFR of > 45 mL/min/1.73m2. We utilised the newly developed SRF-based formula for predicting NBGFR in a living kidney donor population. Counselling of donor post-operative renal outcomes may then be optimised pre-operatively.

Development of a novel score (RENSAFE) to determine probability of acute kidney injury and renal functional decline post surgery: A multicenter analysis

OBJECTIVE

To create and validate 2 models called RENSAFE (RENalSAFEty) to predict postoperative acute kidney injury (AKI) and development of chronic kidney disease (CKD) stage 3b in patients undergoing partial (PN) or radical nephrectomy (RN) for kidney cancer.

METHODS

Primary objective was to develop a predictive model for AKI (reduction >25% of preoperative eGFR) and de novo CKD≥3b (<45 ml/min/1.73m2), through stepwise logistic regression. Secondary outcomes include elucidation of the relationship between AKI and de novo CKD≥3a (<60 ml/min/1.73m2). Accuracy was tested with receiver operator characteristic area under the curve (AUC).

RESULTS

AKI occurred in 452/1,517 patients (29.8%) and CKD≥3b in 116/903 patients (12.8%). Logistic regression demonstrated male sex (OR = 1.3, P = 0.02), ASA score (OR = 1.3, P < 0.01), hypertension (OR = 1.6, P < 0.001), R.E.N.A.L. score (OR = 1.2, P < 0.001), preoperative eGFR<60 (OR = 1.8, P = 0.009), and RN (OR = 10.4, P < 0.0001) as predictors for AKI. Age (OR 1.0, P < 0.001), diabetes mellitus (OR 2.5, P < 0.001), preoperative eGFR <60 (OR 3.6, P < 0.001) and RN (OR 2.2, P < 0.01) were predictors for CKD≥3b. AUC for RENSAFE AKI was 0.80 and 0.76 for CKD≥3b. AKI was predictive for CKD≥3a (OR = 2.2, P < 0.001), but not CKD≥3b (P = 0.1). Using 21% threshold probability for AKI achieved sensitivity: 80.3%, specificity: 61.7% and negative predictive value (NPV): 88.1%. Using 8% cutoff for CKD≥3b achieved sensitivity: 75%, specificity: 65.7%, and NPV: 96%.

CONCLUSION

RENSAFE models utilizing perioperative variables that can predict AKI and CKD may help guide shared decision making. Impact of postsurgical AKI was limited to less severe CKD (eGFR<60 ml/min 71.73m2). Confirmatory studies are requisite.

New-onset Chronic Kidney Disease After Surgery for Localised Renal Masses in Patients with Two Kidneys and Preserved Renal Function: A Contemporary Multicentre Study

Background

There is a lack of evidence on acute kidney injury (AKI) and new-onset chronic kidney disease (CKD) after surgery for localised renal masses (LRMs) in patients with two kidneys and preserved baseline renal function.

Objective

To evaluate the prevalence and risk of AKI and new-onset clinically significant CKD (csCKD) in patients with a single renal mass and preserved renal function after being treated with partial (PN) or radical (RN) nephrectomy.

Design setting and participants

We queried our prospectively maintained databases to identify patients with a preoperative estimated glomerular filtration rate (eGFR) of ≥60 ml/min/1.73 m² and a normal contralateral kidney who underwent PN or RN for a single LRM (cT1-T2N0M0) between January 2015 and December 2021 at four high-volume academic institutions.

Intervention

PN or RN.

Outcome measurements and statistical analysis

The outcomes of this study were AKI at hospital discharge and the risk of new-onset csCKD, defined as eGFR <45 ml/min/1.73 m², during the follow-up. Kaplan-Meier curves were used to examine csCKD-free survival according to tumour complexity. A Multivariable logistic regression analysis assessed the predictors of AKI, while a multivariable Cox regression analysis assessed the predictors of csCKD. Sensitivity analyses were performed in patients who underwent PN.

Results and limitations

Overall, 2469/3076 (80%) patients met the inclusion criteria. At hospital discharge, 371/2469 (15%) developed AKI (8.7% vs 14% vs 31% in patients with low- vs intermediate- vs high-complexity tumours, p < 0.001). At the multivariable analysis, body mass index, history of hypertension, tumour complexity, and RN significantly predicted the occurrence of AKI. Among 1389 (56%) patients with complete follow-up data, 80 events of csCKD were recorded. The estimated csCKD-free survival rates were 97%, 93% and 86% at 12, 36, and 60 mo, respectively, with significant differences between patients with high- versus low-complexity and high- versus intermediate-complexity tumours (p = 0.014 and p = 0.038, respectively). At the Cox regression analysis, age-adjusted Charlson Comorbidity Index, preoperative eGFR, tumour complexity, and RN significantly predicted the risk of csCKD during the follow-up. The results were similar in the PN cohort. The main limitation of the study was the lack of data on eGFR trajectories within the 1st year after surgery and on long-term functional outcomes.

Conclusions

The risk of AKI and de novo csCKD in elective patients with an LRM and preserved baseline renal function is not clinically negligible, especially in those with higher-complexity tumours. While baseline nonmodifiable patient/tumour-related characteristics modulate this risk, PN should be prioritised over RN to maximise nephron preservation if oncological outcomes are not jeopardised.

Patient summary

In this study, we evaluated how many patients with a localised renal mass and two functioning kidneys, who were candidates for surgery at four referral European centres, experienced acute kidney injury at hospital discharge and significant renal functional impairment during the follow-up. We found that the risk of acute kidney injury and clinically significant chronic kidney disease in this patient population is not negligible, and was associated with specific baseline patient comorbidities, preoperative renal function, tumour anatomical complexity, and surgery-related factors, in particular the performance of radical nephrectomy.

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.

Robotic Partial Nephrectomy for Bilateral Renal Masses

PURPOSE OF REVIEW

There are very few data on patients undergoing robot-assisted partial nephrectomy (RAPN) for bilateral renal masses. The aim of this review is to update the literature and discuss the controversial points on this topic.

RECENT FINDINGS

Nine papers have been published regarding RAPN for bilateral renal masses. In particular, five papers were case reports while the remaining four reported patient series. Concerning the outcomes, all these papers highlighted the safety, feasibility, and efficacy of bilateral RAPN for bilateral renal masses. The literature confirmed RAPN as an optimal procedure for the treatment of bilateral renal masses. However, these outcomes mainly derived from selected group of patients who underwent complex surgical procedures by expert robotic surgeons at high volume centers and cannot be generalizable to all categories of patients or centers. The simultaneous bilateral approach resulted feasible showing some advantages and without higher complications than a staged procedure in particular when clampless or selective clamping techniques were performed.

Novel Biomarkers for Early Detection of Acute Kidney Injury and Prediction of Long-Term Kidney Function Decline after Partial Nephrectomy

Background: Identifying acute kidney injury (AKI) within few hours of onset is certainly helpful. However, early prediction of a long-term eGFR decline may be an even more important goal. Our aim was to identify and compare serum [creatinine, kineticGFR, cystatin C, neutrophil gelatinase–associated lipocalin (NGAL)] and urinary (NephroCheck, NGAL, proteinuria, albuminuria, acantocytes at urinary sediment) predictors of AKI that might efficiently predict long-term GFR decline after robotic Nephron-Spearing Surgery (rNSS). Methods: Monocentric prospective observational study. Patients scheduled for rNSS for suspected localized Renal Cell Carcinoma from May 2017 to October 2017 were enrolled. Samples were collected preoperatively and postoperatively (timepoints: 4 h, 10 h, 24 h, 48 h), while kidney function was re-assessed up to 24 months. Results: 38 patients were included; 16 (42%) developed clinical AKI. The eGFR decline at 24 months was more pronounced after postoperative AKI (−20.75 vs. −7.20, p < 0.0001). KineticGFR at 4 h (p = 0.008) and NephroCheck at 10 h (p = 0.001) were, at multivariable linear regression analysis, efficient predictors of post-operative AKI and long-term eGFR decline if compared to creatinine (R2 0.33 vs. 0.04). Conclusions: NephroCheck and kineticGFR have emerged as promising noninvasive, accurate, and early biomarkers of postoperative AKI and long-term GFR decline after rNSS. Combining NephroCheck and kineticGFR in clinical practice would allow to identify high risk of postoperative AKI and long-term GFR decline as early as 10 h after surgery.

The Role of Three-dimensional Model in Preoperative Communication Before Partial Nephrectomy and Postoperative Management

Objective

To investigate the role of the three-dimensional (3D) image reconstruction technique in preoperative communication before partial nephrectomy (PN) and postoperative follow-up.

Methods

A retrospective study was performed with 158 renal cancer patients treated with PN at our center from May 1, 2017 to April 30, 2019. 81 patients (group A) had preoperative communication using the 3D reconstruction technique, while 77 patients (group B) did not. The surgeon explained the anatomical structure, tumor characteristics, and surgical approach in detail to the two groups of patients. Each patient completed a questionnaire. The loss to follow-up rate over a 3-year period was counted for both groups, and non-cancer-related serious complications such as renal failure and cardio-cerebrovascular disease were observed. This research did not include patients who returned for follow-up care owing to associated complications such as postoperative chronic kidney disease. Comparisons between two groups were performed using the Mann-Whitney U test and chi-square test.

Results

All patients showed no statistically significant differences in basic clinical parameters, such as age, gender, body mass index, tumor size, and R.E.N.A.L. score (P ​> ​0.05). In group A, patients were significantly more likely to experience understanding of renal anatomy (P ​= ​0.001), characteristics of renal cell carcinoma (P ​= ​0.003), surgical approach (P ​= ​0.007), and relief of preoperative anxiety (P ​= ​0.013). The follow-up adherence at 3 years postoperatively in group A and group B was 21 cases and 10 cases, respectively (P ​= ​0.041). In addition, glomerular filtration rate < 60 ​mL/min/1.73 ​m² or serum creatinine > 186 ​μmol/L at 3 years after surgery occurred in 5 patients in group A and 13 in group B (P ​= ​0.034), and a systolic blood pressure rise greater than 20 ​mmHg occurred in 9 patients in group A and 18 in group B (P ​= ​0.041).

Conclusions

The use of 3D reconstruction techniques for preoperative communication can successfully improve patients' perception and comprehension of kidney tumors and PN, as well as help to prevent serious postoperative non-cancer-related complications.

External validation of yonsei nomogram predicting chronic kidney disease development after partial nephrectomy: An international, multicenter study

OBJECTIVE

To externally validate Yonsei nomogram.

METHODS

From 2000 through 2018, 3526 consecutive patients underwent on-clamp PN for cT1 renal masses at 23 centers were included. All patients had two kidneys, preoperative eGFR ≥60 ml/min/1.73 m2, and a minimum follow-up of 12 months. New-onset CKD was defined as upgrading from CKD stage I or II into CKD stage ≥III. We obtained the CKD-free progression probabilities at 1, 3, 5, and 10 years for all patients by applying the nomogram found at https://eservices.ksmc.med.sa/ckd/. Thereafter, external validation of Yonsei nomogram for estimating new-onset CKD stage ≥III was assessed by calibration and discrimination analysis.

RESULTS AND LIMITATION

Median values of patients' age, tumor size, eGFR and follow-up period were 47 years (IQR: 47-62), 3.3 cm (IQR: 2.5-4.2), 90.5 ml/min/1.73 m2 (IQR: 82.8-98), and 47 months (IQR: 27-65), respectively. A total of 683 patients (19.4%) developed new-onset CKD. The 5-year CKD-free progression rate was 77.9%. Yonsei nomogram demonstrated an AUC of 0.69, 0.72, 0.77, and 0.78 for the prediction of CKD stage ≥III at 1, 3, 5, and 10 years, respectively. The calibration plots at 1, 3, 5, and 10 years showed that the model was well calibrated with calibration slope values of 0.77, 0.83, 0.76, and 0.75, respectively. Retrospective database collection is a limitation of our study.

CONCLUSIONS

The largest external validation of Yonsei nomogram showed good calibration properties. The nomogram can provide an accurate estimate of the individual risk of CKD-free progression on long-term follow-up.

Age-Related Differences in Oncological Outcomes in Renal Cell Carcinoma: Impact of Functional Conservation as Measured by Postoperative eGFR

INTRODUCTION

We sought to determine whether loss of renal function increases risk of recurrence and metastases in renal cell carcinoma (RCC), and whether this impact was age-related.

MATERIALS AND METHODS

We performed a retrospective analysis of the International Marker Consortium for Renal Cancer (INMARC) registry. Patients were separated into younger (<65 years old) and elder (≥65 years old) age groups, and rates of de novo estimated glomerular filtration rate (eGFR<45 mL/min/1.73m2 [eGFR<45]) were calculated. Multivariable analysis (MVA) was conducted for predictors of progression-free survival (PFS) and all-cause mortality (ACM). Kaplan-Meier Analysis (KMA) was conducted for PFS and overall survival (OS) in younger and elder age groups stratified by functional status.

RESULTS

We analyzed 1805 patients (1113 age<65, 692 age≥65). On MVA in patients <65, de novo eGFR<45 was independently associated with greater risk for worsened progression (HR=1.61, P=.038) and ACM (HR=1.82, P=.018). For patients ≥65, de novo eGFR<45 was not independently associated with progression (P=.736), or ACM (P=.286). Comparing patients with de novo eGFR<45 vs. eGFR ≥45, KMA demonstrated worsened 5-year PFS and OS in patients <65 (PFS: 68% vs. 86%, P<.001; OS: 73% vs. 90%, P<.001), while in patients ≥65, only 5-year OS was worsened (77% vs. 81%, P<.021).

CONCLUSION

Development of de novo eGFR<45 was associated with more profound impact on patients <65 compared to patients ≥65, being an independent risk factor for PFS and ACM. The mechanisms of this phenomenon are unclear but underscore desirability for nephron preservation when safe and feasible in younger patients.

Surgical Management of Synchronous, Bilateral Renal Masses: A 1-decade Referral Center Experience

BACKGROUND

Management and decision-making in patients with bilateral renal masses are controversial.

OBJECTIVE

To report our experience of surgical management in patients with bilateral renal masses undergoing surgery at a high-volume center.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively collected data from patients treated with partial nephrectomy (PN) or radical nephrectomy for bilateral renal masses at a single referral institution between June 2008 and June 2019. Patient- and tumor-related features, timing (one vs two stage), and surgical approach (open vs robotic) were analyzed.

SURGICAL PROCEDURE

A one- versus two-stage strategy was adopted according to the opportunity to perform at least one PN using a clampless or selective-clamping approach, in order to avoid acute kidney injury.

MEASUREMENTS

Operative time, warm ischemia time, and intra- and postoperative complications were recorded. Histopathological results and tumor histology were assessed.

RESULTS AND LIMITATIONS

Overall, 41 patients were included. The median age was 67 yr and the median preoperative estimated glomerular filtration rate (eGFR) was 84 ml/min/1.73 m². The median Preoperative Aspects and Dimensions Used for an Anatomical (PADUA) score was 8 (interquartile range [IQR] 7-8) for both sides. In 17 (42%) patients, a simultaneous approach was chosen, with a pure robotic approach in 11/17 cases, while among the 24 (58.6%) patients treated with a two-stage strategy, 15 (62.5%) were treated with a robotic approach on both sides. Intraoperative complications and postoperative major (CDC ≥3) complications were recorded in 7.3% and 4.9% of cases, respectively. The overall positive surgical margins rate was 2.4%. At a median follow-up of 42 (IQR 18-59) mo, the median eGFR was 73 (IQR 64-80) ml/min/1.73 m², while disease-free survival and cancer-specific mortality were 90.2% and 7.3%, respectively.

CONCLUSIONS

Our experience underlines that both simultaneous and staged surgical treatment of patients with bilateral renal masses are feasible and safe if grounded on proper patient selection.

PATIENT SUMMARY

Management of patients with bilateral renal masses is challenging, given the heterogeneity of clinical scenarios and the need to optimize the timing of treatment to achieve maximal functional preservation while ensuring oncological efficacy.

Robot-assisted versus conventional laparoscopic partial nephrectomy for renal hilar tumors: Parenchymal preservation and functional recovery

OBJECTIVE

To determine whether robot-assisted laparoscopic partial nephrectomy (RALPN) can benefit patients in terms of functional recovery in the treatment of renal hilar tumors compared to conventional laparoscopic partial nephrectomy (CLPN).

METHODS

Between January 2019 and July 2021, patients with hilar tumors who underwent partial nephrectomy (PN) were acquired at our center and were classified into RALPN and CLPN groups. Ipsilateral parenchymal volume (IPV) and glomerular filtration rate (GFR) were determined independently 3-5 days before and 3 months after PN using contrast-enhanced computed tomography and nuclear renal scans. Pearson correlation was used to determine the link between ipsilateral GFR preservation and IPV preserved. Concurrently, multivariable analysis was employed to determine characteristics associated with functional recovery.

RESULTS

A total of 96 patients with hilar tumors were studied, of which 41 received RALPN and 55 received CLPN. Excisional parenchymal volume was 27 and 37 cm³ (p = 0.005) in RALPN and CLPN groups, respectively, and IPV preserved was 77% and 68% (p < 0.001). Furthermore, the ipsilateral GFR preserved was 77.7% and 75.3%, respectively (p = 0.003). On Pearson correlation, ipsilateral GFR preservation was linked with IPV preserved (r = 0.36, p < 0.001). According to a multivariate study, baseline GFR, IPV preserved, and surgical procedures (RALPN vs. CLPN) were significant factors influencing functional recovery.

CONCLUSION

Our study suggests that RALPN, rather than CLPN, can achieve better functional recovery in the treatment of hilar tumors due to its ability to win more IPV preserved. RALPN should be recommended as the first-line treatment for hilar tumors, but randomized controlled trials are required to validate our findings.

Predicting GFR after radical nephrectomy: the importance of split renal function

PURPOSE

To evaluate a conceptually simple model to predict new-baseline-glomerular-filtration-rate (NBGFR) after radical nephrectomy (RN) based on split-renal-function (SRF) and renal-functional-compensation (RFC), and to compare its predictive accuracy against a validated non-SRF-based model. RN should only be considered when the tumor has increased oncologic potential and/or when there is concern about perioperative morbidity with PN due to increased tumor complexity. In these circumstances, accurate prediction of NBGFR after RN can be important, with a threshold NBGFR > 45 ml/min/1.73m² correlating with improved overall survival.

METHODS

236 RCC patients who underwent RN (2010-2012) with preoperative imaging (CT/MRI) and relevant functional data were included. NBGFR was defined as GFR 3-12 months post-RN. SRF was determined using semi-automated software that provides differential parenchymal-volume-analysis (PVA) from preoperative imaging. Our SRF-based model was: Predicted NBGFR = 1.24 (× Global GFR_Pre-RN) (× SRF_{Contralateral}), with 1.24 representing the mean RFC estimate from independent analyses. A non-SRF-based model was also assessed: Predicted NBGFR = 17 + preoperative GFR (× 0.65)-age (× 0.25) + 3 (if tumor > 7 cm)-2 (if diabetes). Alignment between predicted/observed NBGFR was assessed by comparing correlation coefficients and area-under-the-curve (AUC) analyses.

RESULTS

The correlation-coefficients (r) were 0.87/0.72 for SRF-based/non-SRF-based models, respectively (p = 0.005). For prediction of NBGFR > 45 ml/min/1.73m², the SRF-based/non-SRF-based models provided AUC of 0.94/0.87, respectively (p = 0.044).

CONCLUSION

Previous non-SRF-based models to predict NBGFR post-RN are complex and omit two important parameters: SRF and RFC. Our proposed model prioritizes these parameters and provides a conceptually simple, accurate, and clinically implementable approach to predict NBGFR post-RN. SRF can be easily obtained using PVA software that is affordable, readily available (FUJIFILM-Medical-Systems), and more accurate than nuclear-renal-scans. The SRF-based model demonstrates greater predictive-accuracy than a non-SRF-based model, including the clinically-important predictive-threshold of NBGFR > 45 ml/min/1.73m².

The Role of Circulating Biomarkers in the Oncological Management of Metastatic Renal Cell Carcinoma: Where Do We Stand Now?

Renal cell carcinoma (RCC) is an increasingly common malignancy that can progress to metastatic renal cell carcinoma (mRCC) in approximately one-third of RCC patients. The 5-year survival rate for mRCC is abysmally low, and, at the present time, there are sparingly few if any effective treatments. Current surgical and pharmacological treatments can have a long-lasting impact on renal function, as well. Thus, there is a compelling unmet need to discover novel biomarkers and surveillance methods to improve patient outcomes with more targeted therapies earlier in the course of the disease. Circulating biomarkers, such as circulating tumor DNA, noncoding RNA, proteins, extracellular vesicles, or cancer cells themselves potentially represent a minimally invasive tool to fill this gap and accelerate both diagnosis and treatment. Here, we discuss the clinical relevance of different circulating biomarkers in metastatic renal cell carcinoma by clarifying their potential role as novel biomarkers of response or resistance to treatments but also by guiding clinicians in novel therapeutic approaches.

Utilization of Renal Mass Biopsy for T1 Renal Lesions across Michigan: Results from MUSIC-KIDNEY, A Statewide Quality Improvement Collaborative

BACKGROUND

Renal mass biopsy (RMB) has had limited and varied utilization to guide management of renal masses (RM).

OBJECTIVE

To evaluate utilization of RMB for newly diagnosed cT1 RMs across diverse practice types and assess associations of outcomes with RMB.

DESIGN SETTING AND PARTICIPANTS

MUSIC-KIDNEY commenced data collection in September 2017 for all newly presenting patients with a cT1 RM at 14 diverse practices. Patients were assessed at ≥120 d after initial evaluation.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Demographics and outcomes were compared for patients undergoing RMB versus no RMB. Clinical and demographic characteristics were summarized by RMB status using a χ2 test for categorical variables and Student t test for continuous variables. A mixed-effects logistic regression model was constructed to identify associations with RMB receipt.

RESULTS AND LIMITATIONS

RMB was performed in 15.5% (n = 282) of 1808 patients with a cT1 RM. Practice level rates varied from 0% to 100% (p = 0.001), with only five of 14 practices using RMB in >20% of patients. On multivariate analysis, predictors of RMB included greater comorbidity (Charlson comorbidity index ≥2 vs 0: odds ratio [OR] 1.44; p = 0.025) and solid lesion type (cystic vs solid: OR 0.17; p = 0.001; indeterminate vs solid: OR 0.58; p = 0.01). RMB patients were less likely to have benign pathology at intervention (5.0% vs 13.5%; p = 0.01). No radical nephrectomies were performed for patients with benign histology at RMB. The limitations include short follow-up and inclusion of practices with low numbers of RMBs.

CONCLUSIONS

Utilization of RMB varied widely across practices. Factors associated with RMB include comorbidities and lesion type. Patients undergoing RMB were less likely to have benign histology at intervention.

PATIENT SUMMARY

Current use of biopsy for kidney tumors is low and varies across our collaborative. Biopsy was performed in patients with greater comorbidity (more additional medical conditions) and for solid kidney tumors. Pretreatment biopsy is associated with lower nonmalignant pathology detected at treatment.

Predictive models for chronic kidney disease after radical or partial nephrectomy in renal cell cancer using early postoperative serum creatinine levels

Background

Several predictive factors for chronic kidney disease (CKD) following radical nephrectomy (RN) or partial nephrectomy (PN) have been identified. However, early postoperative laboratory values were infrequently considered as potential predictors. Therefore, this study aimed to develop predictive models for CKD 1 year after RN or PN using early postoperative laboratory values, including serum creatinine (SCr) levels, in addition to preoperative and intraoperative factors. Moreover, the optimal SCr sampling time point for the best prediction of CKD was determined.

Methods

Data were retrospectively collected from patients with renal cell cancer who underwent laparoscopic or robotic RN (n = 557) or PN (n = 999). Preoperative, intraoperative, and postoperative factors, including laboratory values, were incorporated during model development. We developed 8 final models using information collected at different time points (preoperative, postoperative day [POD] 0 to 5, and postoperative 1 month). Lastly, we combined all possible subsets of the developed models to generate 120 meta-models. Furthermore, we built a web application to facilitate the implementation of the model.

Results

The magnitude of postoperative elevation of SCr and history of CKD were the most important predictors for CKD at 1 year, followed by RN (compared to PN) and older age. Among the final models, the model using features of POD 4 showed the best performance for correctly predicting the stages of CKD at 1 year compared to other models (accuracy: 79% of POD 4 model versus 75% of POD 0 model, 76% of POD 1 model, 77% of POD 2 model, 78% of POD 3 model, 76% of POD 5 model, and 73% in postoperative 1 month model). Therefore, POD 4 may be the optimal sampling time point for postoperative SCr. A web application is hosted at https://dongy.shinyapps.io/aki_ckd.

Conclusions

Our predictive model, which incorporated postoperative laboratory values, especially SCr levels, in addition to preoperative and intraoperative factors, effectively predicted the occurrence of CKD 1 year after RN or PN and may be helpful for comprehensive management planning.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02976-2.

Does Reduced Renal Function Predispose to Cancer-specific Mortality from Renal Cell Carcinoma?

BACKGROUND

Recent publications have reported an association between increased renal cancer-specific mortality (CSM) and reduced renal function "below safety limits," and advocated for partial nephrectomy (PN) even for potentially aggressive/complex tumors. We hypothesize that this association may be related to confounding factors rather than a consequence of functional differences.

OBJECTIVE

To assess whether there is an independent association between preoperative estimated glomerular filtration rate (eGFR) or new baseline eGFR (NB-GFR) and CSM in patients undergoing PN or radical nephrectomy (RN).

DESIGN, SETTING, AND PARTICIPANTS

A single-center retrospective review was performed. All clinically and pathologically confirmed T1-T3a/N0/M0 renal cancer patients undergoing PN/RN (1999-2008, n = 1605) with adequate functional/oncological data were included.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was CSM. Secondary endpoints were cancer recurrence (CR) and all-cause mortality (ACM). Cox regression analyses investigated endpoints and predictive factors.

RESULTS AND LIMITATIONS

The median age was 60 yr and 64% of patients were male. Comorbidities included hypertension (60%), cardiovascular disease (19%), diabetes (21%), and chronic kidney disease (22%). PN was performed in 954 patients (59%). The median preoperative eGFR and NB-GFR were 80 and 60 ml/min/1.73 m², respectively. Median tumor diameter was 3.6 cm (interquartile range [IQR] = 2.4, 5.5); 70% of tumors were clear cell and 40% were of high grade. Pathology revealed pT1-2/N0/M0 and pT3a/N0/M0 in 81% and 19%, respectively. The median follow-up among survivors was 11.5 yr (IQR = 4, 14). Cancer-specific survival, recurrence-free survival, and overall survival were 94%, 88%, and 73% at 10 yr, respectively. On multivariable analysis, increased age (hazard ratio [HR] = 1.03, p =  0.04), increased tumor size (HR = 1.24, p <  0.01), tumor grade 3/4 (HR = 3.17, p <  0.01), and clear-cell histology (HR = 2.92, p <  0.01) were associated with increased hazard of CSM. Neither preoperative eGFR nor NB-GFR was significantly associated with CSM or CR (all p >  0.1), while an increased preoperative eGFR was associated with reduced hazard of ACM (HR = 0.87, p <  0.01). Limitations include retrospective design and a potential selection bias.

CONCLUSIONS

Our data do not support oncological protection of greater preservation of renal function and confirm that unfavorable oncological outcomes for localized RCC are mostly associated with aggressive tumor characteristics.

PATIENT SUMMARY

We did not find an association between greater preservation of renal function and oncological outcomes for kidney cancer.

Elevated preoperative C-reactive protein is associated with renal functional decline and non-cancer mortality in surgically treated renal cell carcinoma: analysis from the INternational Marker Consortium for Renal Cancer (INMARC)

OBJECTIVE

To investigate association of preoperative C-reactive protein (CRP) and non-cancer mortality (NCM) in a cohort of patients undergoing surgery for localised renal cell carcinoma (RCC).

PATIENTS AND METHODS

Retrospective multicentre analysis of patients surgically treated for clinical Stage 1-2 RCC from 2006 to 2017, excluding all cases of cancer-specific mortality. Descriptive analyses were obtained between the pre-treatment normal-CRP (≤5 mg/L) and elevated-CRP (>5 mg/L) groups. The primary outcome was NCM. The secondary outcomes included progression to de novo chronic kidney disease Stages 3-4 (estimated glomerular filtration rate [eGFR] of <60, <45, and <30 mL/min/1.73 m² ). Multivariable analyses (MVA) were performed to assess for risk factors associated with functional decline and NCM, and Kaplan-Meier analysis was used to obtain survival estimates for outcomes.

RESULTS

A total of 1987 patients who underwent radical or partial nephrectomy were analysed (normal-CRP group, n = 963; elevated-CRP group, n = 1024). Groups were similar in age (59 vs 60 years, P = 0.079). An elevated CRP was more frequent in males (36.8% vs 27.8%, P < 0.001), African-Americans (22.6% vs 2.9%, P < 0.001), and in those with a higher median body mass index (30 vs 25 kg/m² , P < 0.001) and larger median tumour size (4.5 vs 3.3 cm, P < 0.001). On MVA, an elevated CRP was independently associated with development of de novo eGFR of <60 mL/min/1.73 m² (hazard ratio [HR] 1.32, P = 0.015), <45 mL/min/1.73 m² (HR 1.41, P = 0.023) and <30 mL/min/1.73 m² (odds ratio 2.23, P < 0.001). The MVA for factors associated with NCM demonstrated increasing age (HR 1.06, P < 0.001), preoperative elevated CRP (HR 2.18, P < 0.001) and an eGFR of <45 mL/min/1.73 m² (HR 1.16; P = 0.021) as independent risk factors. Kaplan-Meier analysis revealed significantly higher 5-year NCM in the elevated-CRP group vs the normal-CRP group (98% vs 80%, P < 0.001).

CONCLUSIONS

Pre-treatment elevated CRP was independently associated with both progressive renal functional decline and NCM in patients undergoing surgery for Stage 1-2 RCC. Patients with elevated CRP and Stage 1 and 2 RCC may be considered as having indication for nephron-sparing strategies, which may be prioritised if oncologically appropriate.

Associations of urological malignancies with renal progression and mortality in advanced chronic kidney disease: a propensity-matched cohort study

Background

Urological malignancy (UM) in patients with chronic kidney disease (CKD) is an added burden to their overall morbidity and mortality. UM is itself a common cause of CKD. Understanding the associations of UM with outcomes in advanced CKD can help in optimisation of the management of these patients. This study investigates the distribution and association of urological malignancy with outcomes (renal progression and mortality) in patients with advanced non-dialysis dependent CKD.

Methods

The study was conducted in 2637 of 3115 patients recruited in the Salford Kidney Study between the years 2002 and 2016. A comparative analysis was performed between 160 patients with UM (at baseline and incident) and 2477 patients with no malignancy. Cox-regression models and Kaplan-Meir estimates were used to explore the association between the presence of UM with mortality and renal outcome. Linear regression analysis was used to calculate the rate of progression of CKD in the groups. A 1:3 propensity score matched cohort of 640 patients was generated and utilised in the above analyses.

Results

4.4% had a history of UM at baseline with the annual incident rate being 0.37%. The site of malignancy was the kidney in 40% with comparable numbers for prostatic malignancy (39%). 70% (111/160) of UM patients had a medical cause as their primary diagnosis for CKD. Over a median follow up of 4 years, 34% (905) patients died. In the matched sample, the proportion of deaths was similar between the groups (UM 44% versus no malignancy 48%, p = 0.36). 30% reached end-stage renal disease (ESRD) with no difference between the groups. In the Cox-regression model, UM did not prove to be a risk factor associated with either all-cause mortality (HR:1.03; CI: 0.79–1.35; p = 0.81) or reaching ESRD (HR:1.12; CI: 0.80–1.58; p = 0.49). The rate of decline in estimated glomerular filtration rate (eGFR) was similar between the groups (− 1.05 vs − 1.25 mL/min/1.73m²/year, p = 0.31).

Conclusions

There was no correlation observed between UM and all-cause mortality or ESRD. Medical causes of CKD have a significant influence on the outcomes in patients with UM, whereas the UM did not. Hence, a coordinated approach with early liaison between the urology and nephrology teams is needed in the management of UM patients with CKD.

Chronic Kidney Disease After Partial Nephrectomy in Patients With Preoperative Inconspicuous Renal Function - Curiosity or Relevant Issue?

BACKGROUND

Chronic kidney disease (CKD) is a severe long-term complication after partial nephrectomy (PN). Clinical and scientific focus lies on patients with impaired renal function at the time of surgery. Little data is available on patients with normal preoperative renal function (NPRF).

PATIENTS AND METHODS

Patients who underwent PN with a preoperative estimated glomular filtration rate > 60 mL/min/1.73m² were retrospectively examined at 8 European urologic centers. The occurrence of new onset CKD ≥ stage III after surgery (sCKD) was defined as the primary endpoint. Group comparisons and risk correlations were determined. Based on this data, a risk stratification model for sCKD was developed.

RESULTS

Of the 1315 patients with NPRF included, 249 (18.9%) developed sCKD after a median follow-up of 44 months (range, 6-255 months). Pair analysis and univariable regression revealed age, arterial hypertension, American Society of Anesthesiologists score, tumor stage, surgical approach, intraoperative blood loss, perioperative blood transfusions and preoperative CKD stage as predictors for sCKD development. Multivariate analysis confirmed perioperative blood transfusion (hazard ratio [HR], 2.96; P ≤ .0001), age (≥ 55 years; HR, 2.60; P = .0002), tumor stage (> pT1; HR, 2.15; P = .025), and preoperative CKD stage (stage II vs. I; HR, 3.85; P ≤ .0001) as independent risk factors. A model that stratified patient risk for new onset CKD was highly significant (P < .0001).

CONCLUSION

Every fifth patient with NPRF developed sCKD following PN. Elderly patients with higher tumor stage and who require blood transfusion appear to be at increased risk. Based on our risk stratification, patients with ≥ 2 risk factors are candidates for an early, nephrologic follow-up.

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.

Renal Function Impairment Below Safety Limits Correlates With Cancer-specific Mortality in Localized Renal Cell Carcinoma: Results From a Single-center Study

BACKGROUND

A recent multi-center study showed how estimated glomerular filtration rate (eGFR) and cancer-specific mortality (CSM) are linearly and inversely related in organ-confined renal cell carcinoma (RCC) whenever the eGFR decreases below specific thresholds. We addressed our previous work limitations related to heterogeneity and missing data, and explored the relationship between eGFR and CSM also in locally advanced RCC.

MATERIALS AND METHODS

All patients with RCC treated with either partial or radical nephrectomy from 1990 to 2018 at a single institution and with complete data on renal function were included. eGFR was managed as a time-dependent variable. The relationship between eGFR and CSM was analyzed using a Fine and Gray multivariable competing risks framework. Subdistribution hazard ratios (SHRs) were calculated accounting for deaths from other causes.

RESULTS

Multivariable competing risks analysis showed a "piecewise" relationship between eGFR and CSM, with an inverse linear correlation for eGFR values below 85 mL/min. Below this breakpoint, a significant relationship existed between eGFR and CSM in both clinical (SHR, 1.27; P < .001) and pathologic (SHR, 1.27; P = .001) models in stage I to II RCC subgroup. Conversely, no significance was recorded in this subgroup when considering eGFR values above 85 mL/min. In the stage III to IV subgroup, no significant relationships were recorded, regardless of eGFR values. The retrospective design with inherent biases in data collection represents a limitation.

CONCLUSIONS

In patients undergoing surgery for stage I to II RCC, preservation of renal function over "safety limits" is protective from CSM.

The role of three-dimensional reconstruction in laparoscopic partial nephrectomy for complex renal tumors

BACKGROUND

To evaluate the role of three-dimensional (3D) reconstruction technique in renal function protection and ipsilateral parenchymal mass preserved after laparoscopic partial nephrectomy (LPN) in patients with complex renal tumor (R.E.N.A.L.score ≥ 8).

METHODS

A retrospective study enrolling 49 patients who suffered from RCC and underwent LPN at our center, from October 1, 2017, to October 31, 2018. Twenty-one patients (group A) underwent LPN with the 3D reconstruction technique before surgery, and the other 28 patients (group B) not. Preoperative and postoperative ipsilateral parenchymal mass volume and ipsilateral glomerular filtration rate (GFR) were analyzed 3-5 days prior and 3 months after PN. In order to compare the two groups, Mann-Whitney U test and chi-square tests were performed. The main limitation of this technique is that the volume calculations are partly performed manually.

RESULTS

All patients' median renal score was 10 with no difference between the two groups (P = 0.89), and the median tumor size of the two groups was 3.2 cm (group A) and 3.3 cm (group B) respectively (P = 0.14). In addition, the median warm ischemia time of the two groups was 21 min (group A) and 26 min (group B) (P = 0.003). In group A and group B, the rate of preserved global GFR was 88% and 86% (P = 0.06), preserved ipsilateral GFR was 80% and 77% (P = 0.01), and preserved ipsilateral parenchymal was 84% and 80% (P = 0.03) separately.

CONCLUSION

3D reconstruction technique was a beneficial method for more renal function and more preserved renal parenchymal mass volume after LPN.

TRIAL REGISTRATION

Yantai Yuhuangding Hospital, YHD[2017]212. Registered 1 January 2017 (prospectively registered), http://www.ytyhdyy.com/nav/103.htm .

Chronic kidney disease after nephrectomy: a clinically-significant entity?

Worldwide, the kidney is the ninth and 14th most common primary site of cancer in men and women respectively. Surgical management with either radical or partial nephrectomy is the mainstay of treatment. Surgical resection of functional kidney parenchyma is associated with reductions in glomerular filtration rate, and can lead to the development of chronic kidney disease (CKD); however, there is currently debate as to whether CKD secondary to surgical removal of a kidney is of clinical significance. Here, it will be argued that CKD is of clinical significance regardless of aetiology, due to the higher cardiovascular and mortality risk which is associated with low glomerular filtration rate.

Below Safety Limits, Every Unit of Glomerular Filtration Rate Counts: Assessing the Relationship Between Renal Function and Cancer-specific Mortality in Renal Cell Carcinoma

BACKGROUND

The hypothesis that renal function could influence oncological outcomes is supported by anecdotal literature.

OBJECTIVE

To determine whether estimated glomerular filtration rate (eGFR) is related to cancer-specific mortality (CSM) in patients who had undergone surgery for renal cell carcinoma (RCC).

DESIGN, SETTING, AND PARTICIPANTS

A retrospective analysis of 3457 patients who underwent radical (39%) or partial nephrectomy (61%) for cT1-2 RCC between 1990 and 2015.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The eGFR was calculated by the Chronic Kidney Disease Epidemiology Collaboration equation. CSM was analyzed in a multivariable competing-risk framework, estimating the subdistribution hazard ratio (SHR) accounting for deaths from other causes. The relationship between eGFR and CSM was investigated from multiple statistical approaches-extended Cox regression with eGFR incorporated as a time-dependent covariate, landmark analysis, and joint modeling. Other predictors were selected by competing-risk random forest method and backward elimination.

RESULTS AND LIMITATIONS

The relationship between eGFR and CSM was graphically described by a linear spline, i.e. a continuous piecewise linear function with two lines joined by a knot. For eGFR treated as a time-dependent covariate, the knot was located at 65ml/min; at landmark analysis with eGFR at the baseline, 12 mo, and last functional follow-up, the knots were 85, 60, and 65ml/min, respectively. In multivariable competing-risk analysis, CSM was associated with eGFR only for values of eGFR below these cutoffs, with SHRs for every 10ml/min of reduction in eGFR of 1.25 (p=0.003), 1.16 (p=0.028), 1.44 (p=0.02), and 1.16 (p=0.042), corresponding to time-dependent eGFR, and eGFR at baseline, 12 mo, and last functional follow-up, respectively. Joint modeling confirmed these results. A retrospective design with inherent biases in data collection represents a limitation.

CONCLUSIONS

In patients undergoing surgery for RCC, renal function should be preserved in order to improve cancer-related survival.

PATIENT SUMMARY

The relationship between renal function and probability of dying due to renal cancer is complex. The present study found a correlation between glomerular filtration rate and cancer specific mortality that could reconsider the oncological role of renal function in patients undergoing surgery for renal cancer.

Predictors of new-onset chronic kidney disease in patients managed surgically for T1a renal cell carcinoma: An Australian population-based analysis

BACKGROUND

New-onset chronic kidney disease (CKD) following surgical management of kidney tumors is common. This study evaluated risk factors for new-onset CKD after nephrectomy for T1a renal cell carcinoma (RCC) in an Australian population-based cohort.

METHODS

There were 551 RCC patients from the Australian states of Queensland and Victoria included in this study. The primary outcome was new-onset CKD (eGFR <60 mL/min per 1.73 m² ) and the secondary outcome was new-onset moderate-severe CKD (<45 mL/min per 1.73 m² ). Multivariable logistic regression was used to evaluate associations between patient, tumor and health-service characteristics and these outcomes.

RESULTS

Forty percent (219/551) of patients developed new-onset CKD, and 12% (68/551) experienced new-onset moderate-severe CKD. Risk factors for new-onset CKD were age, lower preoperative eGFR, tumor size >20 mm, radical nephrectomy, lower hospital caseloads (<20 cases/year), and rural place of residence. The associations between rural place of residence and low center volume were a consequence of higher radical nephrectomy rates.

CONCLUSION

Risk factors for CKD after nephrectomy generally relate to worse baseline health, or likelihood of undergoing radical nephrectomy. Surgeons in rural centres and hospitals with low caseloads may benefit from formalized integration with specialist centers for continued professional development and case-conferencing, to assist in management decisions.

Outcome Measures Used to Report Kidney Function in Studies Investigating Surgical Management of Kidney Tumours: A Systematic Review

CONTEXT

Most practice decisions relevant to preserving kidney function in patients managed surgically for kidney tumours are driven by observational studies. A wide range of outcome measures are used in these studies, which reduces comparability and increases the risk of reporting bias.

OBJECTIVE

To comprehensively and succinctly describe the outcomes used to evaluate kidney function in studies evaluating surgical management of kidney tumours.

EVIDENCE ACQUISITION

Electronic search of the PubMed database was conducted to identify studies with at least one measure of kidney function in patients managed surgically for kidney tumours, published between January 2000 and September 2017. Abstracts were initially screened for eligibility. Full texts of articles were then evaluated in more detail for inclusion. A narrative synthesis of the evidence was conducted.

EVIDENCE SYNTHESIS

A total of 312 studies, involving 127905 participants, were included in this review. Most were retrospective (n=274) studies and conducted in a single centre (n=264). Overall, 78 unique outcome measures were identified, which were grouped into six outcome categories. Absolute postoperative kidney function (n=187), relative kidney function (n=181), and postoperative chronic kidney disease (n=131) were most frequently reported. Kidney function was predominantly quantified using estimated glomerular filtration rate or creatinine clearance (n=255), most using the modification of diet in renal disease equation (n=182). Only 70 studies provided rationale for specific outcome measures used.

CONCLUSIONS

There is significant variability in the reporting and quantification of kidney function in studies evaluating patients managed surgically for kidney tumours. A standardised approach to measuring and reporting kidney function will increase the effectiveness of outcomes reported and improve relevance of research findings within a clinical context.

PATIENT SUMMARY

Although we know that the removal of a kidney can reduce kidney function, clinical significance of various approaches is a matter of debate. This article demonstrates significant variability in the way kidney function was reported across all studies of patients with kidney cancer undergoing surgery, indicating a need for standardisation.