Aquaporin-1 Protein Levels Elevated in Fresh Urine of Renal Cell Carcinoma Patients: Potential Use for Screening and Classification of Incidental Renal Lesions

Introduction and Objectives. There are over 65,000 new cases of renal cell carcinoma (RCC) each year, yet there is no effective clinical screening test for RCC. A single report claimed no overlap between urine levels of aquaporin-1 (AQP1) in patients with and without RCC (Mayo Clin Proc. 85:413, 2010). Here, we used archived and fresh RCC patient urine to validate this report. Methods. Archived RCC, fresh prenephrectomy RCC, and non-RCC negative control urines were processed for Western blot analysis. Urinary creatinine concentrations were quantified by the Jaffe reaction (Nephron 16:31, 1976). Precipitated protein was dissolved in 1x SDS for a final concentration of 2 μg/µL creatinine. Results. Negative control and archived RCC patient urine failed to show any AQP1 protein by Western blot analysis. Fresh RCC patient urine is robustly positive for AQP1. There was no signal overlap between fresh RCC and negative control, making differentiation straightforward. Conclusions. Our data confirms that fresh urine of patients with RCC contains easily detectable AQP1 protein. However, archival specimens showed an absence of detectable AQP1 indistinguishable from negative control. These findings suggest that a clinically applicable diagnostic test for AQP1 in fresh urine may be useful for detecting RCC

Preoperative Erythrocyte Sedimentation Rate Independently Predicts Overall Survival in Localized Renal Cell Carcinoma following Radical Nephrectomy

Objectives. To determine the relationship between preoperative erythrocyte sedimentation rate (ESR) and overall survival in localized renal cell carcinoma (RCC) following nephrectomy. Methods. 167 patients undergoing nephrectomy for localized RCC had ESR levels measured preoperatively. Receiver Operating Characteristics curves were used to determine Area Under the Curve and relative sensitivity and specificity of preoperative ESR in predicting overall survival. Cut-offs for low (0.0–20.0 mm/hr), intermediate (20.1–50.0 mm/hr), and high risk (>50.0 mm/hr) groups were created. Kaplan-Meier analysis was conducted to assess the univariate impact of these ESR-based groups on overall survival. Univariate and multivariate Cox regression analysis was conducted to assess the potential of these groups to predict overall survival, adjusting for other patient and tumor characteristics. Results. Overall, 55.2% were low risk, while 27.0% and 17.8% were intermediate and high risk, respectively. Median (95% CI) survival was 44.1 (42.6–45.5) months, 35.5 (32.3–38.8) months, and 32.1 (25.5–38.6) months, respectively. After controlling for other patient and tumor characteristics, intermediate and high risk groups experienced a 4.5-fold (HR: 4.509, 95% CI: 0.735–27.649) and 18.5-fold (HR: 18.531, 95% CI: 2.117–162.228) increased risk of overall mortality, respectively. Conclusion. Preoperative ESR values represent a robust predictor of overall survival following nephrectomy in localized RCC

External validation of the modified Glasgow prognostic score for renal cancer

Purpose: The modified Glasgow prognostic Score (mGPS) incorporates C-reactive protein and albumin as a clinically useful marker of tumor behavior. The ability of the mGPS to predict metastasis in localized renal cell carcinoma (RCC) remains unknown in an external validation cohort. Patients and Methods: Patients with clinically localized clear cell RCC were followed for 1 year post-operatively. Metastases were identified radiologically. Patients were categorized by mGPS score as low-risk (mGPS = 0 points), intermediate-risk (mGPS = 1 point) and high-risk (mGPS = 2 points). Univariate, Kaplan-Meier and multivariate Cox regression analyses examined Recurrence -free survival (RFS) across patient and disease characteristics. Results: Of the 129 patients in this study, 23.3% developed metastases. Of low, intermediate and high risk patients, 10.1%, 38.9% and 89.9% recurred during the study. After accounting for various patient and tumor characteristics in multivariate analysis including stage and grade, only mGPS was significantly associated with RFS. Compared with low-risk patients, intermediate- and high-risk patients experienced a 4-fold (hazard ratios [HR]: 4.035, 95% confidence interval [CI]: 1.312-12.415, P = 0.015) and 7-fold (HR: 7.012, 95% CI: 2.126-23.123 P < 0.001) risk of metastasis, respectively. Conclusions: mGPS is a robust predictor of metastasis following potentially curative nephrectomy for localized RCC. Clinicians may consider mGPS as an adjunct to identify high-risk patients for possible enrollment into clinical trials or for patient counselin

A novel preoperative inflammatory marker prognostic score in patients with localized and metastatic renal cell carcinoma

Objective: Several inflammatory markers have been studied as potential biomarkers in renal cell carcinoma (RCC), however few reports have analyzed their prognostic value in aggregate and in non-clear cell histologies. We hypothesize that a combination of specific inflammatory markers into an RCC Inflammatory Score (RISK) could serve as a rigorous prognostic indicator of overall survival (OS) in patients with clear cell and non-clear cell RCC. Methods: Combination of preoperative C-reactive protein (CRP), albumin, erythrocyte sedimentation rate (ESR), corrected calcium, and aspartate transaminase to alanine transaminase (AST/ALT) ratio was used to develop RISK. RISK was developed using grid-search methodology, receiver-operating-characteristic (ROC) analysis, and sensitivity-specificity trade-off analysis. Prognostic value of RISK was analyzed using the Kaplan–Meier method and Cox proportional regression models. Predictive accuracy was compared with RISK to Size, Size, Grade, and Necrosis (SSIGN) score, University of California-LOS Angeles (UCLA) Integrated Staging System (UISS), and Leibovich Prognosis Score (LPS). Results: Among 391 RCC patients treated with nephrectomy, area under the curve (AUC) for RISK was 0.783, which was comparable to SSIGN (AUC 0.776, p = 0.82) and UISS (AUC 0.809, p = 0.317). Among patients with localized disease, AUC for RISK and LPS was 0.742 and 0.706, respectively (p = 0.456). On multivariate analysis, we observed a step-wise statistically significant inverse relationship between increasing RISK group and OS (all p < 0.001). Conclusion: RISK is an independent and significant predictor of OS for patients treated with nephrectomy for clear cell and non-clear cell RCC, with accuracy comparable to other histopathological prognostic tools