VOLUME-WEIGHTED MEAN NUCLEAR VOLUME IN RENAL-CELL CARCINOMA

Objectives. Tumor grade and stage are the most important prognostic pa rameters for renal cell carcinoma (RCC). The value of histologic nucle ar grading, however, is impaired by the inconsistency of pathologists' observations. Estimate of volume-weighted mean nuclear volume (MNV), based on a stereologic method, is correlated with prognosis of bladder , prostate, and endometrial cancer. In this study, we investigated the prognostic value of stereologic estimation of nuclear volume in RCC. Methods. This study included 62 patients with RCC who underwent radica l nephrectomy between 1989 and 1996. Patients were evaluated in two gr oups: patients with locally advanced and/or metastatic disease were pa rt of the poor prognosis group and patients with localized disease wer e part of the good prognosis group. Unbiased estimates of MNV were com pared with histologic grade, tumor stage, and growth pattern according to Thoenes classification. Group means were compared using the nonpar ametric Kruskal-Wallis one-way analysis of variance. Univariate analys is of the data was performed for MNV and time to death, metastasis, lo cal recurrence, and disease-free survival by paired sample t test. For categorical variables, Pearson's correlation test was used for statis tical analysis. Results. There was no correlation between MNV and pati ent sex, age, tumor stage, and growth pattern. MNV showed a trend to b e higher in sarcomatoid and chromophilic cell types than in chromophob e and clear cell types (P < 0.05). MNV values were significantly highe r with increasing grades but no MNV cutoff levels could be defined. Th e MNV values were not different between localized and locally advanced and/or metastatic disease. Conclusions. Our results indicate that est imates of MNV are not useful for predicting disease outcome. Further s tudies are needed to set up reproducible intervals of tumor dedifferen tiation that could be carried out in routine practice for predicting p rogression. (C) 1998, Elsevier Science Inc. All rights reserved.