Glickman Urological and Kidney Institute, Cleveland Clinic Foundation, Cleveland, Ohio.
Louis Stokes Veterans Affairs Medical Center, Cleveland, Ohio.
J Urol. 2021 May;205(5):1310-1320. doi: 10.1097/JU.0000000000001549. Epub 2020 Dec 24.
Preoperative estimation of new baseline glomerular filtration rate after partial nephrectomy or radical nephrectomy for renal cell carcinoma has important clinical implications. However, current predictive models are either complex or lack external validity. We aimed to develop and validate a simple equation to estimate postoperative new baseline glomerular filtration rate.
For development and internal validation of the equation, a cohort of 7,860 patients with renal cell carcinoma undergoing partial nephrectomy/radical nephrectomy (2005-2015) at the Veterans Affairs National Health System was analyzed. Based on preliminary analysis of 94,327 first-year postoperative glomerular filtration rate measurements, new baseline glomerular filtration rate was defined as the final glomerular filtration rate within 3 to 12 months after surgery Multivariable linear regression analyses were applied to develop the equation using two-thirds of the renal cell carcinoma Veterans Administration cohort. The simplest model with the highest coefficient of determination (R) was selected and tested. This model was then internally validated in the remaining third of the renal cell carcinoma Veterans Administration cohort. Correlation/bias/accuracy/precision of equation were examined. For external validation, a similar cohort of 3,012 patients with renal cell carcinoma from an outside tertiary care center (renal cell carcinoma-Cleveland Clinic) was independently analyzed.
New baseline glomerular filtration rate (in ml/minute/1.73 m) can be estimated with the following simplified equation: new baseline glomerular filtration rate = 35 + preoperative glomerular filtration rate (× 0.65) - 18 (if radical nephrectomy) - age (× 0.25) + 3 (if tumor size >7 cm) - 2 (if diabetes). Correlation/bias/accuracy/precision were 0.82/0.00/83/-7.5-8.4 and 0.82/-0.52/82/-8.6-8.0 in the internal/external validation cohorts, respectively. Additionally, the area under the curve (95% confidence interval) to discriminate postoperative new baseline glomerular filtration rate ≥45 ml/minute/1.73 m from receiver operating characteristic analyses were 0.90 (0.88, 0.91) and 0.90 (0.89, 0.91) in the internal/external validation cohorts, respectively.
Our study provides a validated equation to accurately predict postoperative new baseline glomerular filtration rate in patients being considered for radical nephrectomy or partial nephrectomy that can be easily implemented in daily clinical practice.
术前评估肾细胞癌患者行部分肾切除术或根治性肾切除术（nephrectomy）后肾小球滤过率（glomerular filtration rate，GFR）的新基线水平具有重要的临床意义。然而，目前的预测模型要么过于复杂，要么缺乏外部有效性。我们旨在开发并验证一种简单的方程，以估算术后新的肾小球滤过率基线。
对退伍军人事务部（VA）国家卫生系统中 7860 例接受肾细胞癌部分肾切除术/根治性肾切除术（2005-2015 年）的患者进行分析，以用于方程的开发和内部验证。基于对 94327 例术后第一年肾小球滤过率测量值的初步分析，新的肾小球滤过率基线被定义为术后 3 至 12 个月内的最终肾小球滤过率。应用多元线性回归分析，使用 VA 肾细胞癌队列的三分之二来开发方程。选择并测试具有最高决定系数（R）的最简单模型。然后，在 VA 肾细胞癌队列的剩余三分之一中对该模型进行内部验证。检验方程的相关性/偏差/准确性/精密度。为了进行外部验证，我们还独立分析了来自外部三级保健中心的 3012 例肾细胞癌患者的类似队列（克利夫兰诊所肾细胞癌数据库）。
新的肾小球滤过率基线（ml/min/1.73m）可以通过以下简化方程来估算：新的肾小球滤过率基线=35+术前肾小球滤过率（×0.65）-18（如果行根治性肾切除术）-年龄（×0.25）+3（如果肿瘤大小>7cm）-2（如果患有糖尿病）。内部/外部验证队列中的相关性/偏差/准确性/精密度分别为 0.82/0.00/83/-7.5-8.4 和 0.82/-0.52/82/-8.6-8.0。此外，受试者工作特征（receiver operating characteristic，ROC）曲线下面积（95%置信区间）以区分术后肾小球滤过率≥45ml/min/1.73m的切点为 0.90（0.88，0.91），内部/外部验证队列中的分别为 0.90（0.89，0.91）。
我们的研究提供了一种经验证的方程，可准确预测接受根治性肾切除术或部分肾切除术的患者术后肾小球滤过率的新基线水平，该方程可在日常临床实践中简便应用。
