PATHOLOGY

Visual estimate of percent of carcinoma predicts recurrence after radical prostatectomy
Manoharan M, Civantos F, Kim SS, Gomez P, Soloway MS
Department of Urology, University of Miami School of Medicine, Florida, USA
J Urol. 2003; 170: 1194-8

• Purpose: Tumor volume is an important prognosticator for predicting prostate cancer recurrence following radical prostatectomy (RP). We assessed the ability of the visual estimate of the percent of carcinoma (VEPC) to predict recurrence.
• Methods and Materials: As performed by 1 surgeon (MSS), 1,114 men underwent radical prostatectomy between 1992 and February 2002. Patients who had less than 12 months of followup, who underwent salvage RP or in whom VEPC was not assessed in the pathology specimen were excluded. VEPC and other clinical variables were analyzed. We performed univariate analysis using the Kaplan-Meier log rank test. Multivariate analysis using Cox proportional hazards regression was performed.
• Results: A total of 692 patients with a mean age of 61 +/- 7 years met the criteria for this analysis. Mean followup was 52 +/- 30 months. Of the patients 17% had biochemical recurrence. Mean VEPC was 25% and 13% in those with and without recurrence, respectively. On univariate analysis all variables were significant predictors of recurrence. However, multivariate analysis showed that the only significant predictors of recurrence were patient age, initial prostate specific antigen 10 ng/ml or greater, RP Gleason 8 to 10, extraprostatic extension, seminal vesicle involvement and VEPC. Based on disease-free survival curves patients were stratified into 3 broad groups, namely low, intermediate and high volume. The HR for biochemical recurrence was 2.1 for the intermediate VEPC group (9.1% to 20%) and 2.7 for the high VEPC group (greater than 20%). In the reference group it was less than 9% (low volume).
• Conclusions: VEPC is a simple and inexpensive method that is an independent predictor of recurrence after RP.
  
  
• Editorial Comment
  One of the most controversial aspects of the pathologic assessment of radical prostatectomy specimens is the measurement of the tumor volume. Nevertheless, as yet, there are no defined standards for reporting the cancer volume in prostatectomy specimens. Some institutions have calculated the tumor volume accurately, using computer-assisted image analysis systems. Because this method is not feasible for the routine clinical practice, other investigators have proposed alternative simpler means for measuring tumor volume, including the diameter of largest tumor focus, the number of tumor foci, the number of involved blocks, the percentage of blocks involved, the use of a 3.0 mm squares grid, or naked eye examination of the glass slides after the pathologist had circled all microscopically identifiable foci of carcinoma with a marking pen (pathologist’s percentage estimate). Recently, we proposed for estimating tumor volume a simple point-count method accessible to all general pathologists working in routine pathology laboratories (Int Braz J Urol. 2003; 29: 113-120).
  In the present study, tumor volume was an independent predictor of recurrence after radical prostatectomy. Epstein et al. (J Urol. 1993; 149: 1478-1481) analyzed 185 men who underwent radical retropubic prostatectomy for clinical stage B adenocarcinoma of the prostate. Although tumor volume predicted progression, in a stepwise regression analysis it did not provide independent prognostic information. The authors conclude that although an accurate preoperative assessment of tumor volume remains desirable for the management of patients with prostate cancer, the study demonstrated that measurement of tumor volume in radical prostatectomy specimens need not be performed as part of the routine pathological analysis of radical prostatectomy specimens, since it does not provide additional information beyond that of Gleason score and the status of capsular margins.
  In a recent paper to be presented in the USCAP meeting in Vancouver and to be published as an abstract in the January (2004) issue of Modern Pathology, we studied 123 patients submitted to radical prostatectomy for clinical stages T1c or T2. Using the point-count method for estimating tumor volume, we concluded that shorter time to progression following radical prostatectomy correlated with preoperative PSA and Gleason score but not with tumor extension.
  In a paper addressing prognostic factors in prostate cancer by the College of American Pathologists (Arch Pathol Lab Med. 2000; 124: 995-1000), tumor volume was considered category II, that is, needs confirmation.

Dr. Athanase Billis
Full-Professor of Pathology
State University of Campinas, Unicamp
Campinas, São Paulo, Brazil