Prognostic Value of Microvascular Invasion in Predicting the Cancer Specific Survival and Risk of Metastatic Disease in Renal Cell Carcinoma: A Multicenter Investigation.

Purpose: While microvascular invasion is an accepted risk factor in various cancers, its prognostic role in renal cell carcinoma is still unclear. Therefore, a large multicenter study examining the experience of 5 international institutions was performed to evaluate the prognostic value of microvascular invasion in the occurrence of metastases and cancer specific survival. Materials and Methods: A total of 2,596 patients (475 with microvascular invasion and 2,121 without microvascular invasion) having up to 212 (median 22.4) months of followup were compared for differences in clinicopathological features, occurrence of metastases and cancer specific survival. Results: Patients with microvascular invasion presented with higher age (p = 0.001) and a worse Eastern Cooperative Oncology Group performance status (p <0.0001). Microvascular invasion was associated with larger tumor diameter (p <0.0001), higher Fuhrman grade (p <0.0001), more advanced pT stage (p <0.0001), and the presence of lymph node and distant metastases (p <0.0001). In particular, in nonmetastatic cases worse survival was associated with microvascular invasion (p <0.0001, HR 2.38). Univariate analysis demonstrated a strong correlation between microvascular invasion and cancer specific survival (p <0.0001). However, after controlling for gender, Eastern Cooperative Oncology Group performance status, Fuhrman grade and TNM stage statistical significance was lost. Of interest, low stage tumors with microvascular invasion were strongly correlated with the occurrence of metastases (p <0.0001). Conclusions: Microvascular invasion occurs in nearly 1 of 5 patients with renal cell carcinoma, is tightly correlated with adverse clinicopathological features and is an independent predictor of metastatic spread including in those presenting with low stage tumors. [ABSTRACT FROM AUTHOR]