Metachronous Metastatic Potential of Small Renal Cell Carcinoma: Dependence on Tumor Size

Abstract

OBJECTIVES To evaluate the association between tumor diameter and clinicopathologic characteristics and metastatic potential in small (<= 4 cm) renal cell carcinoma (RCC). METHODS A total of 350 patients with an age range of 24-84 years (median, 54) were included in the study. Patients were categorized according to tumor diameter into 3 groups: <= 2, 2.1-3.0, and 3.1-4.0 cm. RESULTS There were no significant differences in age, sex, histologic type, pathologic stage, and Fuhrman`s grade according to tumor diameter. Tumor size did not predict synchronous metastatic disease. Distant metastases at diagnosis were documented in 2.1%, 1.6%, and 0.0% in patients with RCC of diameter <= 2, 2.1-3, and 3.1-4 cm, respectively. During follow-up, recurrence or metastasis developed in 11 patients (3.5%) with a median time to metastasis of 43 months (range 7-104) in 345 patients with localized (N0M0) RCC. Metastases were diagnosed in 2 patients (0.9%) with RCC <= 3 cm and in 9 patients (7.0%) with RCC 3.1-4.0 cm. Significant difference was noted in metastasis-free survival among groups (P = .023). Multivariate Cox proportional hazards model analysis showed that only tumor diameter was an independent predictor of metastasis-free survival (Hazard ratio, 5.344; 95% confidence interval, 1.137-25.127; P = .034). CONCLUSIONS Our findings suggest that risk of metachronous metastasis, but not synchronous metastasis, increases in RCC of diameter >3.0 cm. UROLOGY 74: 1271-1275, 2009. (C) 2009 Elsevier Inc.