RESUMO
OBJECTIVE: To determine the relative prognostic importance of microvascular invasion in apparently localized renal cell carcinoma (RCC). PATIENTS AND METHODS: A retrospective clinical and pathological review was conducted of 176 consecutive patients identified from pathology records who had a nephrectomy for RCC with a median follow-up of 44 months. Vascular invasion was recorded and categorized by the level of microvascular invasion (MVI), renal vein invasion (RVI) and inferior vena cava invasion (IVCI). Tumour type, grade and size were also assessed. These variables were assessed by univariate and multivariate analysis to determine their effect on disease-free survival. RESULTS: In the univariate analysis tumour size, grade, vascular invasion and young age each predicted reduced disease-free survival. On multivariate analysis for all 176 patients, grade, vascular invasion and young age were the significant independent predictors of reduced disease-free survival. In a subgroup of 149 patients from whom those with very high risk determinants were excluded (those with grade 4 tumours and/or IVCI) most of the risk of metastasis could be accounted for by vascular invasion and young age alone (MVI vs no vascular invasion, hazard ratio 3.18, 95% confidence interval 1.29-7.84; RVI vs no vascular invasion 2.41, 0.989-5.89; and age per year 0.963, 0.94-0.992). CONCLUSIONS: Grade, vascular invasion and young age are the main independent predictors of relapse in clinically localized RCC after nephrectomy. For most patients, who do not have very high risk indicators, the main adverse predictors are vascular invasion and young age. These findings are important when selecting patients for trials of adjuvant therapy and have implications for pathological staging.
