Evaluation of microvascular invasion as a prognostic factor in the progression of non-metastatic renal cancer

INTRODUCTION: The aim of this study was to describe the prognostic impact of microvascular invasion (MVI) in patients with non-metastatic renal cell cancer. MATERIAL AND METHODS: We carried out a retrospective, descriptive and analytical study of patients with non-metastatic renal cell carcinoma who had undergone a radical or partial nephrectomy. Patients were divided according to the presence of MVI. In each group, clinical and pathological characteristics were evaluated. Metastasis-free and cancer-specific survival was evaluated by the Kaplan Meier method. The multivariate analysis was performed with Cox proportional method in order to predict risk factors of metastasis and cancer-specific mortality. RESULTS: A total of 221 patients with a median of 40-month long follow-up were evaluated. Patients with MVI+ were 40 (18%) while those with MVI – were 181 (82%). In the univariate analysis, the presence of MVI had a strong correlation with symptomatic tumors (OR 3.56; p 0.0003), tumor size (OR 12.08; p <0.0001), nuclear grade (OR 6.99; p <0.0001), pathological stage (OR 35.8; p <0.0001), distance metastasis (OR 4.16; p 0.0001), and death by cancer (OR 4.7; p 0.0004). However, in the multivariate analysis it is not presented as an independent predictor of metastasis (HR 0.45; p 0.11) or cancer-specific mortality (HR 0.93; p 0.91). CONCLUSIONS: In our series, MVI is associated with unfavorable tumors characteristics. In spite of this, it does not seem to be an independent predictor for metastasis and death by non-metastatic renal cancer.