Factors Associated with Recovery of Renal Function following Radical Nephrectomy for Kidney Neoplasms

Trends and predictors of changes in renal function after radical nephrectomy for renal tumours

BACKGROUND

Chronic kidney disease (CKD) is a common postoperative complication in patients who undergo radical nephrectomy for renal tumours. However, the factors influencing long-term renal function require further investigation.

OBJECTIVE

This study was designed to investigate the trends in renal function changes and risk factors for renal function deterioration in renal tumour patients after radical nephrectomy.

METHODS

We monitored changes in renal function before and after surgery for 3 years. The progression of renal function was determined by the progression and degradation of CKD stages. Univariate and multivariate logistic regression analyses were used to analyse the causes of renal function progression.

RESULTS

We analysed the data of 329 patients with renal tumours who underwent radical nephrectomies between January 2013 and December 2018. In this study, 43.7% of patients had postoperative acute kidney injury (AKI), and 48.3% had CKD at advanced stages. Further research revealed that patients' renal function stabilized 3 months after surgery. Additionally, renal function changes during these 3 months have a substantial impact on the progression of long-term renal function changes in patients.

CONCLUSION

AKI may be an indicator of short-term postoperative changes in renal function. Renal function tests should be performed in patients with AKI after radical nephrectomy to monitor the progression of functional impairment, particularly within the first 3 months after radical nephrectomy.

Long-term effect of acute ischemic injury on the kidney underwent clamped partial nephrectomy

GFR reaches a new baseline, primarily correlating with nephron-mass preservation, 1-12 months after partial nephrectomy (PN). However, does the ipsilateral GFR experience subsequent decline, and does acute ischemic injury has long-term effect on the operated kidney? 319 patients with two kidneys and unilateral clamped PN were analyzed. All had preoperative, new-baseline, and latest follow-up imaging/serum creatinine levels. Annual ipsilateral GFR decline rate (AIGDR) was defined as new-baseline GFR minus latest follow-up GFR normalized by new-baseline GFR, per year. Spectrum score was used to reflect the degree of acute ischemic injury in the operated kidney. 100 subjects searching for health screening served as controls. Predictive factors for AIGDR were assessed. The median AIGDR was 2.25%, significantly higher than controls (0.88%, p = 0.036). With some contralateral hypertrophy, the global annual GFR decline was similar to that of controls (0.81% vs. 0.88%, p = 0.7). Spectrum score correlated significantly with AIGDR (p = 0.037). These results support that acute ischemic injury has long-term effect on the operated kidney.

Preoperative hydronephrosis is an independent protective factor of renal function decline after nephroureterectomy for upper tract urothelial carcinoma

Objectives

To evaluate the predictive role of pre-nephroureterectomy (NU) hydronephrosis on post-NU renal function (RF) change and preserved eligibility rate for adjuvant therapy in patients with upper tract urothelial carcinoma (UTUC).

Patients and methods

This retrospective study collected data of 1018 patients from the Taiwan UTUC Collaboration Group registry of 26 institutions. The patients were divided into two groups based on the absence or presence of pre-NU hydronephrosis. Estimated glomerular filtration rate (eGFR) was calculated pre- and post-NU respectively. The one month post-NU RF change, chronic kidney disease (CKD) progression, and the preserved eligibility rate for adjuvant therapy were compared for each CKD stage.

Results

404 (39.2%) patients without and 614 (60.8%) patients with pre-NU hydronephrosis were enrolled. The median post-NU change in the eGFR was significantly lower in the hydronephrosis group (-3.84 versus -12.88, p<0.001). Pre-NU hydronephrosis was associated with a lower post-NU CKD progression rate (33.1% versus 50.7%, p< 0.001) and was an independent protective factor for RF decline after covariate adjustment (OR=0.46, p<0.001). Patients with pre-NU hydronephrosis had a higher preserved eligibility rate for either adjuvant cisplatin-based chemotherapy (OR=3.09, 95%CI 1.95-4.69) or immune-oncology therapy (OR=2.31, 95%CI 1.23-4.34).

Conclusion

Pre-NU hydronephrosis is an independent protective predictor for post-NU RF decline, CKD progression, and eligibility for adjuvant therapy. With cautious selection for those unfavorably prognostic, non-metastatic UTUC patients with preoperative hydronephrosis, adjuvant rather than neoadjuvant therapy could be considered due to higher chance of preserving eligibility.

Acute kidney injury and the compensation of kidney function after nephrectomy in living donation

Acute kidney injury (AKI) incidence is growing rapidly, and AKI is one of the predictors of inpatient mortality. After nephrectomy, all the patients have decreased kidney function with AKI and recover from AKI. However, the characteristic and behavior of AKI is different from usual AKI and compensatory kidney function has been well known in the postoperative setting, especially in living donors. In this review, we have focused on the compensation of kidney function after nephrectomy in living donors. We discuss factors that have been identified as being associated with kidney recovery in donors including age, sex, body mass index, remnant kidney volume, estimated glomerular filtration rate, and various comorbidities.

CT-measured Cortical Volume Ratio Is an Accurate Alternative to Nuclear Medicine Split Scan Ratio Among Living Kidney Donors

BACKGROUND

The 125I-iothalamate clearance and 99mTc diethylenetriamine-pentaacetic acid (99mTc-DTPA) split scan nuclear medicine studies are used among living kidney donor candidates to determine measured glomerular filtration rate (mGFR) and split scan ratio (SSR). The computerized tomography-derived cortical volume ratio (CVR) is a novel measurement of split kidney function and can be combined with predonation estimated GFR (eGFR) or mGFR to predict postdonation kidney function. Whether predonation SSR predicts postdonation kidney function better than predonation CVR and whether predonation mGFR provides additional information beyond predonation eGFR are unknown.

METHODS

We performed a single-center retrospective analysis of 204 patients who underwent kidney donation between June 2015 and March 2019. The primary outcome was 1-y postdonation eGFR. Model bases were created from a measure of predonation kidney function (mGFR or eGFR) multiplied by the proportion that each nondonated kidney contributed to predonation kidney function (SSR or CVR). Multivariable elastic net regression with 1000 repetitions was used to determine the mean and 95% confidence interval of R2, root mean square error (RMSE), and proportion overprediction ≥15 mL/min/1.73 m2 between models.

RESULTS

In validation cohorts, eGFR-CVR models performed best (R2, 0.547; RMSE, 9.2 mL/min/1.73 m2, proportion overprediction 3.1%), whereas mGFR-SSR models performed worst (R2, 0.360; RMSE, 10.9 mL/min/1.73 m2, proportion overprediction 7.2%) (P < 0.001 for all comparisons).

CONCLUSIONS

These findings suggest that predonation CVR may serve as an acceptable alternative to SSR during donor evaluation and furthermore, that a model based on CVR and predonation eGFR may be superior to other methods.

Preoperative versus Postoperative Compensation of the Contralateral Normal Kidney in Patients Treated with Radical Nephrectomy for Renal Cell Carcinoma

BACKGROUND

We sought to identify the factors affecting renal compensatory processes that occur preoperatively as well as postoperatively in patients treated with radical nephrectomy (RNx) for renal cell carcinoma (RCC).

METHODS

We retrospectively reviewed the records of 906 patients treated with RNx for RCC. We defined the early compensatory process (process 1) as compensatory adaptation of the contralateral normal kidney (CNK) before RNx. We defined the late compensatory process (process 2) as compensatory adaptation of the CNK after RNx. Total compensation was defined as the combination of these two processes. Multivariable logistic regression analyses were used to identify significant factors associated with processes 1, 2 and total compensation.

RESULTS

Mean preoperative, 1-week, and 5-year postoperative estimated glomerular filtration rates (eGFR) were 84.5, 57.6 and 63.7 mL/min/1.73 m2, respectively. Female sex (p < 0.001), lower body mass index (BMI) (p < 0.001), absence of hypertension (p = 0.019), lower preoperative eGFR (p < 0.001), larger tumor volume (p < 0.001), and larger CNK volume (p < 0.001) were significantly associated with process 1. Younger age (p = 0.019), higher BMI (p < 0.001), and absence of diabetes mellitus (DM) (p = 0.033) were significantly associated with process 2. Female sex (p < 0.001), younger age (p < 0.001), absence of DM (p = 0.002), lower preoperative eGFR (p < 0.001), and larger tumor (p = 0.001) and CNK volumes (p < 0.001) were significantly associated with total compensation.

CONCLUSIONS

Different factors affected each compensatory process. Process 1 made a greater contribution to the entire renal compensatory process than process 2.

A comparison of oncologic and functional outcomes in patients with pt3a renal cell carcinoma treated with partial and radical nephrectomy

HYPOTHESIS

Partial Nephrectomy is oncological safe in patients with pT3a RCC.

PURPOSE

To compare the oncological and functional outcomes of patients with pT3a RCC scheduled for PN and RN.

MATERIALS AND METHODS

We retrospectively reviewed patients with pT3a N0 M0 RCC who underwent partial or radical nephrectomy from 2005 to 2016. Perioperative characteristics, including estimated glomerular filtration rate, tumor size, pathological histology, and RENAL nephrometry score, were compared between patients scheduled for partial or radical nephrectomy. We used multivariable Cox proportional hazards regression models to compare overall survival, cancer-specific survival, and recurrence-free survival between planned procedure type.

RESULTS

Of the 589 patients, 369 (63%) and 220 (37%) were scheduled for radical and partial nephrectomy, respectively; 26 (12%) of the scheduled partial nephrectomy cases were intraoperatively converted to radical nephrectomy. After adjusting for tumor size and histology, there were no statistically significant differences in overall survival (hazard ratio 0.66; 95% CI, 0.38-1.13), cancer-specific survival (hazard ratio 0.53; 95% CI, 0.16-1.75), or recurrence-free survival (hazard ratio 0.66; 95% CI, 0.34-1.28) between patients scheduled for partial or radical nephrectomy. Fewer patients scheduled for partial nephrectomy had estimated glomerular filtration rate reductions 3 to 9 months after surgery than patients scheduled for radical nephrectomy.

CONCLUSION

We found no evidence that patients scheduled to undergo partial nephrectomy had poorer oncologic outcomes than patients scheduled to undergo radical nephrectomy. In select patients with pT3a renal cell carcinoma in whom partial nephrectomy is deemed feasible by the surgeon, partial nephrectomy should not be discouraged.

Acute Kidney Injury Recovery Patterns in Critically Ill Patients: Results of a Retrospective Cohort Study

OBJECTIVES

Acute kidney injury, acute kidney injury severity, and acute kidney injury duration are associated with both short- and long-term outcomes. Despite recent definitions, only few studies assessed pattern of renal recovery and time-dependent competing risks are usually disregarded. Our objective was to describe pattern of acute kidney injury recovery, change of transition probability over time and their risk factors.

DESIGN

Monocenter retrospective cohort study. Acute kidney injury was defined according to Kidney Disease Improving Global Outcomes definition. Renal recovery was defined as normalization of both serum creatinine and urine output criteria. Competing risk analysis, time-inhomogeneous Markov model, and group-based trajectory modeling were performed.

SETTING

Monocenter study.

PATIENTS

Consecutive patients admitted in ICU from July 2018 to December 2018 were included.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Three-hundred fifty patients were included. Acute kidney injury occurred in 166 patients at ICU admission, including 64 patients (38.6%) classified as acute kidney disease according to Acute Disease Quality Initiative definition and 44 patients (26.5%) who could not be classified. Cumulative incidence of recovery was 25 % at day 2 (95% CI, 18-32%) and 35% at day 7 (95% CI, 28-42%). After adjustment, need for mechanical ventilation (subdistribution hazard ratio, 0.42; 95% CI, 0.23-0.74) and severity of the acute kidney injury (stage 3 vs stage 1 subdistribution hazard ratio, 0.11; 95% CI, 0.03-0.35) were associated with lack of recovery. Group-based trajectory modeling identified three clusters of temporal changes in this setting, associated with both acute kidney injury recovery and patients' outcomes.

CONCLUSIONS

In this study, we demonstrate Acute Disease Quality Initiative to allow recovery pattern classification in 75% of critically ill patients. Our study underlines the need to take into account competing risk factors when assessing recovery pattern in critically ill patients.

Can kidney parenchyma metabolites serve as prognostic biomarkers for long-term kidney function after nephrectomy for renal cell carcinoma? A preliminary study

Objective

Nephrectomy, the standard of care for localized renal cell carcinoma (RCC), may lead to kidney function loss. Our goal was to identify prognostic biomarkers of postoperative renal function using metabolomics.

Methods

Metabolomics data from benign kidney parenchyma were collected prospectively from 138 patients with RCC who underwent nephrectomy at a single institution. The primary endpoint was the difference between the postoperative and preoperative estimated glomerular filtration (eGFR) rate divided by the elapsed time (eGFR slope). eGFR slope was calculated ∼2 years post-nephrectomy (GFR1), and at last follow-up (GFR2). A multivariate regularized regression model identified clinical characteristics and abundance of metabolites in baseline benign kidney parenchyma that were significantly associated with eGFR slope. Findings were validated by associating gene expression data with eGFR slope in an independent cohort (n = 58).

Results

Data were compiled on 78 patients (median age 62.6 years, 65.4% males). The mean follow-up was 25 ± 3.4 months for GFR1 and 69.5 ± 23.5 months for GFR2 and 17 (22%) and 32 (41%) patients showed eGFR recovery, respectively. Nephrectomy type, blood lipids, gender and 23 metabolites from benign parenchyma were significantly associated with eGFR slope. Some metabolites associated with eGFR slope overlapped with previously reported chronic kidney disease-related processes. Subgroup analysis identified unique ‘metabolite signatures’ by older age, nephrectomy type and preoperative eGFR.

Conclusions

Nephrectomy type, gender, blood lipids and benign parenchyma metabolites at nephrectomy were associated with long-term kidney function. On further study, these metabolites may be useful as potential biomarkers and to identify novel therapeutic targets for malignancy-associated renal disease.

Predictors of long-term renal function after kidney surgery for patients with preoperative chronic kidney disease

INTRODUCTION

We evaluated the trajectory of estimated glomerular filtration rate (eGFR) after kidney surgery in patients with kidney cancer and chronic kidney disease (CKD).

METHODS

We identified 1204 consecutive patients in our institutional database with preoperative CKD undergoing partial or radical nephrectomy from 1998-2016. Postoperative eGFR was tracked, with patients censored when receiving dialysis or kidney transplantation. A multivariable mixed-effects models assessed associations between preoperative baseline patient and tumor characteristics, and longitudinal eGFR. The Kaplan-Meier method and multivariable Cox regression were used to estimate overall survival, cancer-specific survival, and cumulative incidence of dialysis.

RESULTS

Preoperatively, 892 (74.1%), 271 (22.5%), and 41 (3.4%) patients had CKD stage 3a, 3b, and 4/5, respectively. There were 55 patients dialyzed and 355 deaths (99 from kidney cancer). Median followup was 8.1 years, with 25 781 postoperative eGFR measurements. Factors associated with decreasing eGFR postoperatively included radical nephrectomy, male gender, older age, increased body mass index (BMI), and cardiovascular risk factors. We observed a significant interaction effect between time from surgery and preoperative CKD stage: the eGFR of stage 3a patients improved, while stage ≥3b declined (p<0.001). The two-year and five-year cumulative incidence of dialysis was 1.8% (1.1-2.6%) and 3.1% (2.2-4.2%), respectively. The cumulative incidence of dialysis, with death as a competing event, significantly differed by preoperative CKD stage.

CONCLUSIONS

Preoperative CKD stage ≥3b is independently associated with a higher risk of declining renal function, dialysis, and mortality. With careful selection, patients with preoperative CKD withstand kidney surgery with low rates of dialysis.

The adjuvant treatment of kidney cancer: a multidisciplinary outlook

Approximately 70% of cases of kidney cancer are localized or locally advanced at diagnosis. Among patients who undergo surgery for these cancers, 30-35% will eventually develop potentially fatal metachronous distant metastases. Effective adjuvant treatments are urgently needed to reduce the risk of recurrence of kidney cancer and of dying of metastatic disease. To date, almost all of the tested adjuvant agents have failed to demonstrate any benefit. Only two trials of an autologous renal tumour cell vaccine and of the vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor sunitinib have shown positive results, but these have been criticized for methodological reasons and conflicting data, respectively. The results of two additional trials of targeted agents as adjuvant therapies have not yet been published. Novel immune checkpoint inhibitors are promising approaches to adjuvant therapy in kidney cancer, and a number of trials are now underway. An important component of the management of patients with kidney cancer, particularly those who undergo radical resection for localized renal cell carcinoma, is the preservation of kidney function to reduce morbidity and mortality. The optimal management of these patients therefore requires a multidisciplinary approach involving nephrologists, oncologists, urologists and pathologists.

Organ-sparing procedures in GU cancer: part 1-organ-sparing procedures in renal and adrenal tumors: a systematic review

PURPOSE

Organ-sparing surgery (OSS) for the kidney and adrenals has emerged as the need for preservation of function is paramount in patients with poor functional reserve. As reports increasingly showed that oncological outcomes were equivalent to radical excision, elective OSS became a viable alternative in patients with otherwise normal reserve. In this review, we summarize the current knowledge of OSS for adrenal and renal tumors.

MATERIALS AND METHODS

PubMed, Web of Science and Cochrane Library Central Search were searched for recently published articles up to December 2017. The following keywords were used; "partial adrenalectomy", "adrenal sparing", "partial nephrectomy", "nephron sparing", "kidney/renal cancer".

RESULTS

Partial adrenalectomy became an attractive alternative to total adrenalectomy avoiding adrenal insufficiency. Both minimally invasive surgery and ablative techniques were increasingly reported for adrenal OSS with adequate residual adrenal function and excellent oncological outcome. Radical nephrectomy remained for many years as the gold standard of treatment for organ-confined renal cell carcinoma. As the need to reduce the impact on renal function, more conservative approaches were utilized. Soon, the non-inferiority of nephron-sparing surgery to that of radical excision became evident and elective partial nephrectomy was gaining ground as the standard of care for small renal masses in patients with normal contralateral kidneys.

CONCLUSIONS

Herein, we present a comprehensive review of the current status of OSS in renal and adrenal tumors.

Progression to chronic kidney disease in patients undergoing nephrectomy for small renal masses: a price to pay for a therapeutic success?

Nephrectomy, which constitutes a gold-standard procedure for the treatment of renal-cell carcinoma (RCC), has been widely discussed in the past decade as a significant risk factor of the development of chronic kidney disease (CKD). RCC is the third most common genitourinary cancer in the United States, with an estimated more than 65,000 new cases and 14,970 deaths. The aim of this review was to precisely and comprehensively summarize the status of current knowledge in CKD risk factors after nephrectomy, the advantages of minimally invasive vs. radical nephrectomy, post-nephrectomy biomarkers of CKD, ways of post-operative CKD prevention and, therefore, better understand why various aspects of CKD after nephrectomy. The majority of current studies indicated a better long-term kidney function preservation in patients undergoing partial nephrectomy in comparison to those after radical nephrectomy. Furthermore, a nephron-sparing surgery should be a preferred first-line procedure among young patients with small renal masses. As partial nephrectomy is followed by a greater risk of adverse outcomes relative to radical nephrectomy, a potential survival benefit should always be considered especially in the elderly or patients with comorbidities.

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.

The Effect of Patient and Surgical Characteristics on Renal Function After Partial Nephrectomy

BACKGROUND

The purpose of the study was to identify patient and disease characteristics that have an adverse effect on renal function after partial nephrectomy.

PATIENTS AND METHODS

We conducted a retrospective review of 387 patients who underwent partial nephrectomy for renal tumors between 2006 and 2014. A line plot with a locally weighted scatterplot smoothing was generated to visually assess renal function over time. Univariable and multivariable longitudinal regression analyses incorporated a random intercept and slope to evaluate the association between patient and disease characteristics with renal function after surgery.

RESULTS

Median age was 60 years and most patients were male (255 patients [65.9%]) and white (343 patients [88.6%]). In univariable analysis, advanced age at surgery, larger tumor size, male sex, longer ischemia time, history of smoking, and hypertension were significantly associated with lower preoperative estimated glomerular filtration rate (eGFR). In multivariable analysis, independent predictors of reduced renal function after surgery included advanced age, lower preoperative eGFR, and longer ischemia time. Length of time from surgery was strongly associated with improvement in renal function among all patients.

CONCLUSION

Independent predictors of postoperative decline in renal function include advanced age, lower preoperative eGFR, and longer ischemia time. A substantial number of subjects had recovery in renal function over time after surgery, which continued past the 12-month mark. These findings suggest that patients who undergo partial nephrectomy can experience long-term improvement in renal function. This improvement is most pronounced among younger patients with higher preoperative eGFR.

Renal function recovery after radical nephroureterectomy for upper tract urothelial carcinoma

PURPOSE

To understand the longitudinal renal function trends in patients undergoing radical nephroureterectomy (RNU) and identify clinicopathologic characteristics associated with estimated glomerular filtration rate (eGFR) recovery.

METHODS

147 patients were available for analysis. Longitudinal eGFR trends were assessed by plotting each patient's eGFR measurements over time. The patient population was dichotomized using eGFR < 60 ml/min/1.73 m² versus ≥ 60 ml/min/1.73 m². Cumulative incidence and competing risk regression analysis were used to estimate recovery of postoperative eGFR to the preoperative level and identify clinicopathologic characteristics associated with eGFR recovery.

RESULTS

Median age was 68.7 years and median preoperative eGFR was 55.9 ml/min/1.73 m². 63.6% were male and 95.8% were white. The cumulative incidence of eGFR recovery was significantly higher in patients with baseline eGFR < 60 ml/min/1.73 m² compared to those with baseline eGFR ≥ 60 ml/min/1.73 m² (p = 0.01), with recovery rates at 2 years of 56.6% vs. 27.7%, respectively. Multivariable analysis revealed that preoperative hydronephrosis (HR 1.80) and preoperative eGFR < 60 ml/min/1.73 m² (HR 1.87) were associated with increased chance of eGFR recovery.

CONCLUSION

Over half of patients with preoperative eGFR < 60 ml/min/1.73 m² achieved eGFR recovery within the first 3 years after RNU, and hydronephrosis was a significant predictor of recovery. These findings should be considered when counseling patients regarding chronic kidney disease progression after RNU and timing of perioperative chemotherapy for high risk tumors.

Long-Term Renal Function Recovery following Radical Nephrectomy for Kidney Cancer: Results from a Multicenter Confirmatory Study

PURPOSE

We sought to confirm the findings from a previous single institution study of 572 patients from Memorial Sloan Kettering Cancer Center in which we found that 49% of patients recovered to the preoperative estimated glomerular filtration rate within 2 years following radical nephrectomy for renal cell carcinoma.

MATERIALS AND METHODS

A multicenter retrospective study was performed in 1,928 patients using data contributed from 3 independent centers. The outcome of interest was postoperative recovery to the preoperative estimated glomerular filtration rate. Data were analyzed using cumulative incidence and competing risks regression with death from any cause treated as a competing event.

RESULTS

This study demonstrated that 45% of patients had recovered to the preoperative estimated glomerular filtration rate by 2 years following radical nephrectomy. Furthermore, this study confirmed that recovery of renal function differed according to preoperative renal function such that patients with a lower preoperative estimated glomerular filtration rate had an increased chance of recovery. This study also suggested that larger tumor size and female gender were significantly associated with an increased chance of renal function recovery.

CONCLUSIONS

In this multicenter retrospective study we confirmed that in the long term a large proportion of patients recover to preoperative renal function following radical nephrectomy for kidney tumors. Recovery is more likely among those with a lower preoperative estimated glomerular filtration rate.

Factors associated with acutely elevated serum creatinine following radical tumour nephrectomy: the Correlates of Kidney Dysfunction-Tumour Nephrectomy Database study

BACKGROUND

To identify factors associated with acutely elevated serum creatinine (SCr) within 7 days of radical tumour nephrectomy.

METHODS

The study population consisted of 130 consecutive patients managed for renal tumours. The primary outcome was acute kidney injury (AKI) (defined as SCr increase ≥50% above baseline), assessed using multivariable logistic regression analysis. The secondary outcome was SCr percentage increase, assessed using multivariable linear regression analysis.

RESULTS

Following nephrectomy, the mean percentage increase in SCr in the first week was 55%±29%, and 77 (59%) patients experienced AKI. Independent predictors of AKI post-nephrectomy were male gender [adjusted odds ratio (OR): 2.67; 95% confidence interval (95% CI): 1.01, 6.93], urine albumin-creatinine ratio (OR: 0.66; 95% CI: 0.47, 0.91), preoperative estimated glomerular filtration rate (eGFR) (OR: 1.03; 95% CI: 1.00, 1.05), laparoscopic nephrectomy (OR: 3.02; 95% CI: 1.00, 9.12), and non-clear cell renal cell carcinoma (RCC) (OR: 2.93; 95% CI: 1.04, 8.29). Independent predictors of a SCr increase were male gender (β: 12.0; 95% CI: 2.69, 21.3), urine albumin-creatinine ratio (β: -3.36; 95% CI: -6.55, -0.16), preoperative eGFR (β: 0.38; 95% CI: 0.10, 0.66), laparoscopic nephrectomy (β: 12.7; 95% CI: 1.05, 24.3) and obesity (β: 9.94, 95% CI: 0.61, 19.3).

CONCLUSIONS

Male gender, albuminuria, eGFR and laparoscopic nephrectomy independently associated with acutely elevated serum creatinine following radical tumour nephrectomy.

Predictors of Long-Term Survival after Renal Cancer Surgery

PURPOSE

Renal cancer surgery can adversely impact long-term function and survival. We evaluated predictors of chronic kidney disease 5 years and nonrenal cancer mortality 10 years after renal cancer surgery.

MATERIALS AND METHODS

We analyzed the records of 4,283 patients who underwent renal cancer surgery from 1997 to 2008. Radical and partial nephrectomy were performed in 46% and 54% of patients, respectively. Cumulative probability ordinal modeling was used to predict chronic kidney disease status 5 years after surgery and multivariable logistic regression was used to predict nonrenal cancer mortality at 10 years. Relevant patient, tumor and functional covariates were incorporated, including the preoperative glomerular filtration rate (A), the new baseline glomerular filtration rate after surgery (B) and the glomerular filtration rate loss related to surgery (C), that is C = A - B. In contrast, partial or radical nephrectomy was not used in the models due to concerns about strong selection bias associated with the choice of procedure.

RESULTS

Multivariable modeling established the preoperative glomerular filtration rate and the glomerular filtration rate loss related to surgery as the most important predictors of the development of chronic kidney disease (Spearman ρ = 0.78). Age, gender and race had secondary roles. Significant predictors of 10-year nonrenal cancer mortality were the preoperative glomerular filtration rate, the new baseline glomerular filtration rate, age, diabetes and heart disease (all p <0.05). Multivariable modeling established age and the preoperative glomerular filtration rate as the most important predictors of 10-year nonrenal cancer mortality (c-index 0.71) while the glomerular filtration rate loss related to surgery only changed absolute mortality estimates 1% to 3%.

CONCLUSIONS

Glomerular filtration rate loss related to renal cancer surgery, whether due to partial or radical nephrectomy, influences the risk of chronic kidney disease but it may have less impact on survival. In contrast, age and the preoperative glomerular filtration rate, which reflects general health status, are more robust predictors of nonrenal cancer mortality, at least in patients with good preoperative function or mild chronic kidney disease.

Renal cell carcinoma: new insights and challenges for a clinician scientist

There is a growing recognition of the complex interplay between renal cell cancer (RCC), kidney function, mechanical reduction of nephron mass, and systemic agents targeting the cancer. Earlier detection of RCC and rising life expectancy of cancer survivors places a greater emphasis on preservation of renal function after cancer resection and during systemic therapy. Unique adverse effects associated with RCC drugs not only help reveal cancer pathophysiology but also expand our knowledge of normal cell signaling and metabolism. In this review, we outline our current understanding of RCC biology and treatment, their bidirectional relationship with kidney function, and unmet research needs in this field.

Chronic Kidney Disease Is More Common in Locally Advanced Renal Cell Carcinoma

OBJECTIVE

To retrospectively evaluate clinical predictors of chronic kidney disease (CKD) in renal cell carcinoma (RCC) patients to identify associations between patient- and tumor-specific factors with poorer renal function. CKD and RCC are interrelated, with 26%-44% of RCC patients having concomitant CKD at diagnosis.

PATIENTS AND METHODS

Institutional registries from Spectrum Health and University of California, San Diego, were queried for preoperative glomerular filtration rate and proteinuria status before radical or partial nephrectomy. Preoperative clinical and tumor factors were recorded; proteinuria was classified as A1 (<30 mg), A2 (30-300 mg), and A3 (>300 mg). CKD was grouped by Kidney Disease Improving Global Outcomes classification (low, moderately increased, high, very high).

RESULTS

We evaluated 1569 patients undergoing surgery for renal cortical tumors. CKD status was low risk in 860 (55%), moderately increased in 381 (24%), high in 194 (12%), and very high in 134 (9%) patients. Increased radius, exophytic or endophytic properties, nearness of tumor to the collecting system or sinus in millimeters, anterior or posterior, location relative to polar lines score, tumor size, and clinical tumor stage were strongly associated with increased CKD risk at baseline. Clinical stage T3/T4 disease had more at-risk patients than stages T2 and T1 disease (39.5% vs 22% and 19%, P = .0001). Clinical tumor stage and gender were the only predictors of proteinuria, lower glomerular filtration rate, and higher CKD risk group in both univariate and multivariate analyses.

CONCLUSION

Forty-five percent of patients with RCC had moderate or higher CKD before treatment. A positive correlation between pretreatment CKD and locally advanced RCC (cT3/T4) was present. This likely relates to increased loss of functional parenchyma with increasing tumor size or stage, with important implications in patient management.

Management of Small Renal Masses: American Society of Clinical Oncology Clinical Practice Guideline

Purpose To provide recommendations for the management options for patients with small renal masses (SRMs). Methods By using a literature search and prospectively defined study selection, we sought systematic reviews, meta-analyses, randomized clinical trials, prospective comparative observational studies, and retrospective studies published from 2000 through 2015. Outcomes included recurrence-free survival, disease-specific survival, and overall survival. Results Eighty-three studies, including 20 systematic reviews and 63 primary studies, met the eligibility criteria and form the evidentiary basis for the guideline recommendations. Recommendations On the basis of tumor-specific findings and competing risks of mortality, all patients with an SRM should be considered for a biopsy when the results may alter management. Active surveillance should be an initial management option for patients who have significant comorbidities and limited life expectancy. Partial nephrectomy (PN) for SRMs is the standard treatment that should be offered to all patients for whom an intervention is indicated and who possess a tumor that is amenable to this approach. Percutaneous thermal ablation should be considered an option if complete ablation can reliably be achieved. Radical nephrectomy for SRMs should only be reserved for patients who possess a tumor of significant complexity that is not amenable to PN or for whom PN may result in unacceptable morbidity even when performed at centers with expertise. Referral to a nephrologist should be considered if chronic kidney disease (estimated glomerular filtration rate < 45 mL/min/1.73 m²) or progressive chronic kidney disease occurs after treatment, especially if associated with proteinuria.