PATHOLOGY

Substratification of stage T1C prostate cancer based on the probability of biochemical recurrence
Gretzer MB, Epstein JI, Pound CR, Walsh PC, Partin AW
James Buchanan Brady Urological Institute, Johns Hopkins Medical
Institutions, Baltimore, Maryland, USA
Urology 2002; 60:1034-39

• Objectives: To evaluate the influence of preoperative prostate-specific antigen (PSA), biopsy Gleason sum, and prostate biopsy quantitative histologic findings on the probability of biochemical failure in an attempt to identify criteria to substratify Stage T1c prostate cancer more accurately.
• Methods: We reviewed the records of 1149 patients who underwent prostatectomy for T1c disease between 1988 and 2000. Biochemical recurrence (PSA 0.2 ng/mL or greater) defined the endpoint in this study. Recursive partitioning analysis was used to establish cutpoints for preoperative PSA level, biopsy Gleason sum, number of positive biopsy cores, and maximal percentage of any single biopsy core involved with cancer. These cutoff values were then evaluated using Kaplan-Meier estimations to determine the probability of remaining biochemically recurrence free.
• Results: Using a PSA cutpoint of 10 ng/mL or a biopsy Gleason sum of 7, two groups of patients were identified (T1cI and T1cII). The rate of freedom from PSA recurrence at 3, 5, and 10 years after surgery for T1cI was 98%, 96%, and 96%, respectively, and for T1cII was 86%, 83%, and 73%, respectively (P <0.001). For T1cII patients, the greatest percentage of cancer in a single biopsy core was found to be a predictor of biochemical failure on multivariate analysis and, using a cutoff value of 50%, further stratified the PSA recurrence-free rates for the men in group T1cII (90% and 85% versus 75% and 56% at 5 and 10 years after surgery, respectively, P = 0.03).
• Conclusions: The results of this study demonstrate that within Stage T1c there are two populations of patients with significantly different recurrence probabilities: T1cI (Gleason sum less than 7 and PSA 10 ng/mL or less) and T1cII (Gleason sum 7 or greater or PSA greater than 10 ng/mL). Furthermore, using a cutpoint of 50% of cancer in a single core of biopsy tissue, additional risk stratification is afforded to men with higher risk “T1cII” cancer.
  
  
• Editorial Comment
  Clinical stage T1c is one of the most important issues regarding prostate cancer. Of 557 consecutive men who underwent radical prostatectomy between October 1998 and January 2000 at the Johns Hopkins Medical Institutions, 386 (69%) presented with clinical stage T1c (J Urol. 2002; 168:100-104). In our Institution (Unicamp), 52% of the patients who underwent radical prostatectomy in 2002 presented in this stage. The effort to stratify this clinical stage is worthy. Epstein JI et al. (J Urol. 1998; 160:2407-11) and Noguchi M et al. (J Urol. 2001; 166:104-9) consider T1c cancer as “significant” or “insignificant”, according to pathologic findings on needle biopsy. This stratification relates to cancer volume found in the specimen of the radical prostatectomy. Gretzer MB et al., propose a stratification based on biochemical recurrence (PSA 0.2 ng/mL or greater). According to their results, using a PSA cutpoint of 10 ng/ML or a biopsy Gleason sum of 7, two groups of patients were identified (T1cI and T1cII). This study adds to the “significant” or “insignificant” parameters probabilities of PSA recurrence. It will help the urologist to discuss with his patient this unique condition in oncology (stage T1c prostate cancer).

Dr. Athanase Billis
Chair, Department of Pathology
State University of Campinas, Unicamp
Campinas, São Paulo, Brazil