Role of Volume Weighted Mean Nuclear Volume for Predicting Disease Outcome in Patients with Renal Cell Carcinoma

Abstract

Histological grading of malignancy in renal cell carcinoma is based on qualitative, morphological examination and suffers from poor reproducibility. On the other hand, estimate of volume weighted mean nuclear volume, which was developed based on a stereological technique, is an easy method to perform with high reproducibility. Furthermore, it has been reported that mean nuclear volume is remarkably correlated with prognosis of bladder and prostate cancer. We compared mean nuclear volume to a histological grading method and TNM classification in determining the prognosis of renal cell carcinoma using a Cox proportional hazards model. A retrospective, prognostic study was done of 65 patients with renal cell carcinoma diagnosed by radical nephrectomy or needle punch biopsy between January 1978 and November 1995. Unbiased estimates of mean nuclear volume were compared to TNM classification and histological grading to determine prognostic value. Univariate analysis indicated that all TNM classifications, histological grades and estimates of mean nuclear volume were significantly correlated with prognosis of renal cell carcinoma. However, multivariate analysis revealed that estimates of mean nuclear volume and metastasis at diagnosis were the 2 most powerful independent predictors of disease specific survival. Our results indicate that estimates of mean nuclear volume are prognostically superior to morphological grading of renal cell carcinoma. We recommend mean nuclear volume estimates as an adjunct to subjective histological grading in patients with this disease.