A preoperative model to predict pT3 upstaging in clinically localized renal cell carcinoma

Abstract

Introduction: Patients upstaged to pT3 after partial nephrectomy (PN) may be at an increased risk of disease progression compared to those patients submitted to radical nephrectomy (RN). We sought to identify preoperative factors predicting pT3 upstaging in localized renal cell carcinoma.

Material and methods: Patients submitted to nephrectomy for clinically localized (cT1-cT2) renal cell carcinoma between 2011 and 2016 were identified from a prospective registry, those presenting with locally advanced or metastatic disease were excluded. Clinical factors, laboratory, and imaging using RENAL score, were analyzed. A multivariate analysis was performed looking for stage pT3a predictors.

Results: Two hundred and nine patients were included, 66% were men, with a mean age of 57 years. Mean tumor size was 49 ±31 mm. 19% were staged as pT3a. Of this group, 10% underwent a PN. Age, hypertension, presence of hematuria, creatinine levels, size and RENAL score were statistically associated with locally advanced stage. The variables of the RENAL score that were associated to pT3a stage were size, nearness to renal sinus/collector system and contact with main renal vessels. On the multivariate analysis, only age, size, and contact with renal vessels were found to predict upstaging. A model was developed which was able to predict stage pT3a with an area under the curve (AUC) of 0.864 in the ROC curve.

Conclusions: Upstaging to pT3a is fairly common in clinically localized tumors. A formula that includes tumor size, age and contact with the main vessels on imaging, can help predict it. This should be considered when deciding if the patient is a candidate for nephron sparing surgery.

Keywords: kidney neoplasms; neoplasm staging; nephrectomy; nomograms.

Figure 1

Formula to calculate pT3 predictive score.

Figure 2

pT3 stage predictive nomogram.

Figure 3

Predictive model ROC curve.