Purpose: We assessed whether supplementing the Leibovich prognosis score with vascular invasion would improve prognostic value to predict metastatic disease in patients with nonmetastatic clear cell renal cell carcinoma.
Materials and methods: We retrospectively evaluated the pathology records of 1,754 patients with nonmetastatic clear cell renal cell carcinoma treated with surgery between 1984 and 2006 at a single tertiary academic center. The Leibovich prognosis score was supplemented by additional scoring for vascular invasion. Metastasis-free survival was assessed using the Kaplan-Meier method for each score category. A Cox regression model was used for multivariate testing. Predictive accuracy was determined by the Harrell concordance index and decision curve analysis.
Results: Median followup was 84 months. Ten-year metastasis-free survival probability for a score of 0 to 1 and 2 to 8 or greater was 95%, 83%, 78%, 81%, 69%, 51%, 15% and 13%, respectively. The concordance index was 0.792 compared to 0.778 from our external validation of the Leibovich prognosis score using routine pathological findings (p <0.05). Decision curve analysis also favored the predictive ability of the novel model.
Conclusions: Adding vascular invasion improved the predictive accuracy of our validation data by 1.4% over that of the Leibovich prognosis score. Patients with a score of 7 or greater had a more than 85% probability of metastatic disease at 10 years. Thus, they could be considered candidates for adjuvant treatment trials.
Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.