Volume-weighted mean nuclear volume as a prognostic factor in renal cell carcinoma

Volume-weighted mean nuclear volume (MNV) has been reported to have important prognostic value in many cancers. We investigated the prognostic value of MNV in patients with renal cell carcinoma (RCC). A retrospective study of the 155 patients with RCC treated by radical nephrectomy between 1976 and 1996 was conducted. MNV was evaluated in the surgical specimens using a stereologic technique. Univariate analyses by the log-rank test and then a multivariate analysis by the Cox proportional hazards model were performed to analyze the prognostic value of histopathologic parameters such as Robson stage, tumor-node-metastasis (TNM) classification, tumor grade, and MNV. There were significant correlations between MNV and Robson stage, TNM classification and tumor grade. Robson stage, TNM classification, tumor grade, and MNV were correlated significantly with disease-specific survival of RCC patients. There was no significant difference in disease-specific survival between patients with Grade 1 and Grade 2 tumors (94.8% of all patients), but MNV could predict the clinical outcome of these groups. MNV also was correlated significantly with disease-specific survival at all tumor stages. Multivariate analysis showed pT classification, M classification, tumor grade, and MNV to be independently associated with survival. These studies strongly suggest that MNV may provide new and useful information to accurately predict the prognosis of patients with RCC.