Microvascular Tumor Invasion, Tumor Size and Fuhrman Grade: A Pathological Triad for Prognostic Evaluation of Renal Cell Carcinoma

Abstract

The biological behavior and clinical outcome of renal cell carcinoma are difficult to predict. We investigated the prognostic impact of clinicopathological variables to establish a risk stratification model to predict recurrence and survival rates. We studied 230 patients with renal cell carcinoma (stages T(1-4) N(x) M(0)) who underwent radical nephrectomy and/or nephron sparing surgery, and were followed for a median of 48 months (range 3 to 140). Univariate and multivariate analyses were performed, and the influence of clinical presentation, histological tumor size, tumor grade, lymph node involvement and microvascular tumor invasion on disease-free and cancer specific survival curves was determined. A composition model based on independent prognostic variables was then created to stratify tumors into low, intermediate and high risk of progression. The tumor recurrence rate was 17% (39 of 230) and the cancer specific mortality rate was 13% (31 of 230). Multivariate analyses determined that microvascular tumor invasion, tumor grade and tumor size were the only independent prognostic factors. Disease-free survival rates for low, intermediate and high risk tumors were 94.7%, 56.8% and 13.1%, respectively. Cancer specific survival rates were 94.7%, 61.7% and 32.0%, respectively. Tumor size, Fuhrman grade and microvascular tumor invasion are strong and independent predictors of survival of patients with renal cell carcinoma. Risk assessment and stratification based on this triad of pathological features may allow better individualization of followup schedules and trials of adjuvant treatment for patients with renal cell carcinoma.