Preoperative Decision Making for Nephron-Sparing Procedure in the Renal Mass: Time for Using Standard Tools?

To determine if the application of using standard tools on tumor complexity and comorbidity indexes may replace the traditional choice of nephron-sparing procedure (NSP) based on clinical maximal tumor diameter (cMTD), age, and comorbidity.

Anatomic complexity scores (PADUA and RENAL) and Charlson comorbidity index (CCI) and CCI age-adjusted (CACI) were applied to 261 cases of either nephron-sparing surgery (NSS) or cryoablation (CA). Patient- and tumor-related preoperative variables, PADUA, RENAL, CCI, and CACI, were evaluated for their association and as treatment predictors in uni- and multivariate regression analysis. Discriminative ability of each of the models generated was compared for their receiver operating curve area under the curve (AUC). Survival analysis was performed using log rank tests.

In total, 124 cases underwent partial nephrectomy and 137 cases CA. cMTD, RENAL, PADUA, age, and CACI were independently associated with the choice of NSS. Five models integrating a combination of age, cMTD, CACI, PADUA, and RENAL (scores and complexity groups) showed an AUC >0.72 to predict the odds of receiving NSS. The discriminative ability of these five models was not statistically significantly different.

cMTD, RENAL, PADUA, age, and CACI are preoperative variables independently associated with the choice of NSP. Models incorporating tools on tumor anatomic complexity and CACI may replace the decision-making in the type of NSP based on cMTD and age. The use of these models can be of value for future standardization and comparison.