Body mass index and comorbidity are associated with postoperative renal function after nephrectomy

Perioperative and Mid-term Oncological and Functional Outcomes After Partial Nephrectomy for Complex (PADUA Score ≥10) Renal Tumors: A Prospective Multicenter Observational Study (the RECORD2 Project)

BACKGROUND

Partial nephrectomy (PN) for complex renal masses has a non-negligible risk of perioperative complications. Furthermore, late functional and oncological outcomes of patients submitted to these challenging surgeries still remain to be determined.

OBJECTIVES

To report the perioperative and mid-term oncological and functional outcomes of PN for complex masses (Preoperative Aspects and Dimensions Used for an Anatomical [PADUA] score≥10) in a large multicenter prospective observational study.

DESIGN, SETTING, AND PARTICIPANTS

We prospectively evaluated patients treated with PN for complex renal tumors at 26 urological centers (Registry of Conservative and Radical Surgery for Cortical Renal Tumor Disease [RECORD2] project).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Multivariate logistic regression analyses explored the predictors of surgical complications. Multivariable Cox regression analyses estimated the hazard of renal function loss and disease recurrence. Kaplan-Meier estimates assessed the probability of survival.

RESULTS AND LIMITATIONS

In total, 410 patients who underwent PN for complex masses were evaluated. Clinical T1b and T2 tumors accounted for 43.2% and 9.8% of the cases. Overall, 45.9%, 18.8%, and 35.4% of patients underwent open, laparoscopic, and robotic PN, respectively. Intraoperative complications occurred in 15 (3.6%) patients, while postoperative surgical complications were recorded in 76 (18.5%) patients. At multivariable analysis, preoperative hemoglobin (odds ratio [OR]: 0.67; p<0.001) and open (OR: 3.91; p<0.001) versus robotic surgical approach were found to be the only predictors of surgical complications. An estimated glomerular filtration rate drop of >25% from baseline was observed in 30.2% and 17.6% of patients at 1st month and 2 yr after surgery, respectively. Two-year recurrence-free survival was 97.1%; positive surgical margins (hazard ratio [HR]: 3.35; p=0.009), nucleolar grading (HR: 5.61; p<0.001), and tumor stage (HR: 2.62; p=0.05) were associated with recurrence.

CONCLUSIONS

In a large series, PN for complex renal masses was a safe technique with an acceptable rate of perioperative complications and excellent mid-term oncological and functional results.

PATIENT SUMMARY

In this study, we evaluated peri- and postoperative outcomes of patients treated with partial nephrectomy for complex renal masses. Open surgery was associated with higher complications than the robotic approach. Some histological features were found to be associated with disease recurrence.

Prediction of significant estimated glomerular filtration rate decline after renal unit removal to aid in the clinical choice between radical and partial nephrectomy in patients with a renal mass and normal renal function

OBJECTIVES

To develop a clinically applicable predictive model to quantitate the risk of estimated glomerular filtration rate (eGFR) decline to ≤45 mL/min/1.73 m2 after radical nephrectomy (RN) to better inform decisions between RN and partial nephrectomy (PN).

PATIENTS AND METHODS

Our prospectively maintained kidney cancer registry was reviewed for patients with a preoperative eGFR >60 mL/min/1.73 m2 who underwent RN for a localized renal mass. New baseline renal function was indexed. We used multivariable logistic regression to develop a predictive nomogram and evaluated it using receiver-operating characteristic (ROC) analysis. Decision-curve analysis was used to assess the net clinical benefit.

RESULTS

A total of 668 patients met the inclusion criteria, of whom 183 (27%) experienced a decline in eGFR to ≤45 mL/min/1.73 m2 . On multivariable analysis, increasing age (P = 0.001), female gender (P < 0.001), and increasing preoperative creatinine level (P < 0.001) were associated with functional decline. We constructed a predictive nomogram that included these variables in addition to comorbidities with a known association with kidney disease, but found that a simplified model excluding comorbidities was equally robust (cross-validated area under the ROC curve was 0.78). Decision-curve analysis showed the net clinical benefit at probabilities >~11%.

CONCLUSIONS

The decision to perform RN vs PN is multifaceted. We have provided a simple quantitative tool to help identify patients at risk of a postoperative eGFR of ≤45 mL/min/1.73 m2 , who may be stronger candidates for nephron preservation.

Incident Chronic Kidney Disease After Radical Nephrectomy for Renal Cell Carcinoma

BACKGROUND

Chronic kidney disease (CKD) after surgery for kidney cancer is common, and is associated with increased morbidity and mortality. This study aimed to identify factors associated with incident CKD in patients managed with radical nephrectomy.

PATIENTS AND METHODS

All patients diagnosed with renal cell carcinoma between January 2012 and December 2013 were ascertained from state-based cancer registries in Queensland and Victoria. Information on patient, tumor, and health service characteristics was obtained via chart review. Multivariable logistic regression was used to evaluate exposures associated with incident CKD (estimated glomerular filtration rate [eGFR] <60 mL per minute per 1.73 m²) at 12 months after nephrectomy.

RESULTS

Older age (adjusted odds ratio [aOR] per 5-year increase, 1.5; 95% confidence interval [CI], 1.4-1.6), male sex (aOR, 1.4; 95% CI, 1.0-2.0), obese compared with not obese (aOR, 1.8; 95% CI, 1.2-2.7), rural compared with urban place of residence (aOR, 1.8; 95% CI, 1.1-3.0) were associated with a higher risk of incident CKD. Lower preoperative eGFR was also associated with a higher risk of incident CKD. Management in private compared with public hospitals was also associated with a higher risk of CKD (aOR, 1.6; 95% CI, 1.2-2.2). Factors related to tumor size and cancer severity were also associated with worse postoperative kidney function, although it is likely this was a consequence of selection bias.

CONCLUSION

Patient characteristics have the strongest associations with incident CKD after radical nephrectomy. Potential risk factors were reasonably similar to recognized CKD risk factors for the general population. Patients who undergo nephrectomy who have CKD risk factors might benefit from ongoing postoperative screening for deterioration of kidney function.

Body mass index as independent predictor of overall survival in patients with advanced renal cell carcinoma at start of systemic treatment-Analyses from the German clinical RCC-Registry

OBJECTIVES

A high body mass index (BMI) is associated with an increased risk for developing renal cell carcinoma (RCC), a higher complication rate after surgery, and a postoperative decline in renal function after nephrectomy. In contrast, a high preoperative BMI has been associated with increased survival in patients with localized RCC. We examined the prognostic impact of the BMI in patients treated for metastatic RCC (mRCC) in daily routine practice in Germany.

PATIENTS AND METHODS

The ongoing prospective, multicenter German clinical cohort study on mRCC (RCC-Registry) has recruited patients from more than 110 oncology/urology outpatient centers and hospitals at initiation of systemic first-line treatment. Data on patients' demographics, treatment, and outcome in routine practice, so called "real world data", have been collected. For this analysis, 606 patients were stratified into a low (BMI < 24), medium (24 < BMI < 28), and high (BMI > 28) BMI group. The influence of the BMI on the overall survival (OS) was analyzed using a multivariate Cox proportional hazards model.

RESULTS

Median OS was 24.5 (95% confidence interval [CI], 19.3-28.5), 17.9 (95% CI, 15.3-20.8) and 10.9 (95% CI, 7.3-13.4) months in the high, medium, and low BMI patient group, respectively. A significant correlation of BMI with OS, independent of other factors, was found (low vs. high BMI: hazard ratio (HR): 1.94, 95% CI, 1.48-2.54; medium vs. high BMI: HR: 1.40, 95% CI, 1.10-1.78). Memorial Sloan Kettering Cancer Center risk factors were independently correlated with shorter OS.

CONCLUSIONS

Our analysis showed a significant and independent correlation of a high BMI with longer OS in a prospective German cohort of mRCC routine patients starting first-line systemic treatment.

Impact of Comorbidities on Functional Recovery from Partial Nephrectomy

PURPOSE

Parenchymal mass preservation, and ischemia type and/or duration can influence functional recovery after partial nephrectomy. Some groups have hypothesized that relevant comorbidities may also impact nephron stability and functional recovery but this has not been adequately investigated.

MATERIALS AND METHODS

At our center 405 patients treated with partial nephrectomy from 2007 to 2015 had the necessary data to determine the function and parenchymal mass preserved in the ipsilateral kidney. Comorbidities potentially associated with renal functional status were reviewed, including various degrees of hypertension, diabetes, cardiovascular disease, obesity, smoking status and related medications. Multivariable linear regression was done to assess factors associated with functional recovery, defined as the percent of preserved ipsilateral glomerular filtration rate.

RESULTS

Median tumor size was 3.5 cm and the median R.E.N.A.L. (radius, exophytic/endophytic properties, nearness of tumor to collecting system or sinus, anterior/posterior, location relative to polar lines and tumor touching main renal artery or vein) score was 8. Warm and cold ischemia were done in 264 (65%) and 141 patients for a median duration of 21 and 27 minutes, respectively. The median preserved ipsilateral glomerular filtration rate was 79%. Patient age, comorbidity index, hypertension and proteinuria were each associated with the preoperative glomerular filtration rate (all p <0.01). On univariable and multivariable analyses the preserved parenchymal mass, and ischemia type and duration were significantly associated with functional recovery (all p <0.001). On univariable analysis of comorbidities only hypertension was significantly associated with functional recovery. However, on multivariable analysis none of the analyzed comorbidities were associated with functional recovery.

CONCLUSIONS

Recovery of function after partial nephrectomy depends primarily on parenchymal mass preservation and ischemia characteristics. Comorbidities failed to be associated with functional outcomes. Comorbidities can impact function, leading to surgery, and may influence long-term functional stability. However, our data suggest that they do not influence short-term recovery after partial nephrectomy.