PATOLOGY

Prostate cancer involving the bladder neck: recurrence-free survival and implications for AJCC staging modifications
Dash A, Sanda MG, Yu M, Taylor JMG, Fecko A, Montie JE, Rubin MA
Departments of Urology and Pathology, University of Michigan, Ann Arbor, Michigan, USA
Mod Pathol. 2002; 15:159A

• Purpose: In the AJCC TNM staging system, bladder neck involvement by prostate cancer after radical retropubic prostatectomy is considered pT4 disease, suggesting a high risk for disease recurrence. However, recurrence risk with pathological invasion of the bladder neck (pT4) has not been definitely compared to recurrence risk of extraprostatic extension (pT3a) or seminal vesicle invasion (pT3b). Moreover, evidence to justify the higher (pT4) stage for bladder neck invasion in contemporary cancers is entirely lacking. We therefore compared recurrence risk in cases with bladder neck involvement to recurrence risk in cases with pT3a or pT3b disease.
• Methods and Materials: The study cohort was composed of 1124 men with clinically localized prostate carcinoma treated with radical retropubic prostatectomy between 1994 and present. Prostate specific antigen (PSA)-recurrence was defined as 0.2ng/mL following surgery. Margins were evaluated for focal and extensive involvement. Bladder neck involvement, margin positivity, and all other pathology stage categories were assessed as covariates contributing to PSA-recurrence risk by Cox regression, and relative risk of these pT categories was tabulated.
• Results: Bladder neck involvement was found in 61/1124 (5%) of cases; 46 and 15 of these had focal and extensive involvement of the bladder neck margin, respectively. Seminal vesicle invasion (pT3b) and extraprostatic extension (pT3a) were present in 76 (7%) and 278 (25%) cases, respectively. Cox regression analysis confirmed that pathology stage is a significant risk factor for PSA recurrence; however, the recurrence risk associated with bladder neck involvement (pT4) was less than that of seminal vesicle invasion (pT3b) and not substantially different from that of extraprostatic extension (pT3a).
• Conclusions: The risk of recurrence conferred with bladder neck involvement (AJCC pT4) is not different that with extraprostatic extension (pT3a), or seminal vesicle invasion (pT3b). The AJCC staging system should be evidence-based; however, the current AJCC pathology staging system for bladder neck-involvement is contrary to available evidence; and reclassification of bladder neck involvement as part of the pT3 category, instead of pT4, should be considered.
  
  
• Editorial Comment
  Analyzing the category T of the TNM system of staging (proposed in 1997 or more recently in 2002), we almost overlook the fact that invasion of the bladder neck is considered stage pT4 and therefore, with worse prognosis than invasion of the seminal vesicle(s) (pT3b). This study arouses much interest when presented at the American Congress of Pathology this year in Chicago. A question raised refers to the representation of the bladder neck in the surgical specimen. According to the surgical technique used, including cases with total preservation, the bladder neck is variably represented in the specimen. All studies proposing changes in staging must be evaluated and confirmed by other authors. We had a great interest on this subject and compared recurrence and/or metastases following radical prostatectomy in patients with and without neoplasia in the bladder margin of the surgical specimen. The study was based in 141 patients with a follow-up ranging from 2 months to 62 months (median: 18 months). Recurrence was considered whenever the PSA level was ³ 0.5ng/mL or 3 consecutive levels were increasing. The results showed no statistical difference related to recurrence comparing patients with (pT4) and without bladder neck involvement. On the other hand, the analysis of patients with seminal vesicle invasion (pT3b) showed a significantly higher recurrence of the disease.

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