COMBINING VOLUME-WEIGHTED MEAN NUCLEAR VOLUME WITH GLEASON SCORE AND CLINICAL STAGE TO PREDICT MORE RELIABLY DISEASE OUTCOME OF PATIENTS WITH PROSTATE-CANCER

BACKGROUND. Various criteria for patients with prostate cancer have be en reported to be of prognostic value, and we have reported that estim ates of volume-weighted mean nuclear volume (MNV), developed by Gunder sen and Jensen based on a stereological technique, accurately predict the prognosis of prostate cancer. However, all of these studies were c on ducted on cases in a single institution, and it has remained unclea r whether MNV calculations obtained at one institution apply to cases at another institution. Ln attempting to solve this problem, we made a prognostic index (P.I.) based on data from one hospital, and tested w hether these data could be used to predict the prognosis of patients a t another hospital. MATERIALS AND METHODS. A retrospective, multivaria te prognostic study of 195 patients with prostate cancer, diagnosed at Kyoto University Hospital and treated conservatively, indicated that clinical stage, Gleason score, and MNV were all significantly correlat ed with the prognosis of patients with prostate cancer. From the relat ive strengths of these prognostic factors in a multivariate analysis, the following P.I. was constructed: P.I. = Clinical stage x 1.8040 + G leason score x 1.5245 + MNV x 2.3162 (the constants correspond to the risk ratio estimated by Cox analysis). The P.I. was calculated for 104 patients with prostate cancer diagnosed at Shizuoka City Hospital and treated conservatively for analysis of disease-specific survival. RES ULTS. The prognostic index ranged from 3.841-16.142. Using the median value of 12.5 as a cutoff point, a clear separation of cases with poor and favorable prognosis was achieved (P < 0.0001, observation period: 1-167 months). CONCLUSIONS. The results of this study suggest that es timates of MNV can be evaluated at multiple institutions with the use of P.I. calculation. Furthermore, combining estimates of MNV with Glea son score and clinical stage predicts most powerfully disease outcome of patients with prostate cancer. (C) 1998 Wiley-Liss, Inc.