CALCULATED PROSTATE-CANCER VOLUME - THE OPTIMAL PREDICTOR OF ACTUAL CANCER VOLUME AND PATHOLOGICAL STAGE

Objectives. A new clinical pretreatment quantity called the calculated prostate cancer volume has been defined. The correlation between the calculated parameter and the actual prostate cancer volume, and its ab ility to predict for pathologic Stage T3 disease in patients with clin ically localized disease, is tested. Methods. Prostate cancer volume m easurements were obtained using a 3-dimensional computerized morphomet ric reconstruction technique on 104 whole;mounted radical prostatectom y specimens. The calculated prostate cancer volume was determined base d on pretreatment clinical parameters (prostate-specific antigen [PSA] , biopsy Gleason score, and prostate ultrasound volume). Linear regres sion was used to determine the Pearson correlation coefficients (r) be tween the PSA, the calculated prostate cancer volume, and the measured prostate cancer volume. Logistic regression multivariable analysis ev aluating the predictive value of the pretreatment PSA, biopsy Gleason score, clinical stage, and calculated prostate cancer volume in predic ting pathologic Stage T3 disease in patients with clinically organ-con fined disease was performed. Results. The calculated prostate cancer v olume (r 0.71 to 0.96) was superior to PSA (r 0.12 to 0.67) in predict ing the measured prostate cancer volume over a wide range (0.02 to 9.5 cm(3)) of cancer volumes. The calculated prostate cancer volume was t he only significant predictor (P = 0.02) of pathologic Stage T3 diseas e in patients with clinical Stage T1 to T2 disease on multivariable an alysis. Conclusions. The calculated volume of prostate cancer is super ior to PSA in predicting both the pathologic prostate cancer volume an d pathologic Stage T3 disease in patients with clinical Stage T1 and T 2 disease, Therefore, it may be useful in determining the optimal cand idates for radical prostatectomy. (C) 1997, Elsevier Science Inc.