[707] Pathologic Features of Salvage Radical Prostatectomy Specimens Following Radiotherapy: Implications for Focal Therapeutic Options

L Andino, C Guo, E Chiong, IN Prokhorova, LL Pisters, P Troncoso. UT MD Anderson Cancer Center, Houston, TX

Background: Salvage radical prostatectomy is a therapeutic option offered to patients with clinically localized, recurrent prostate cancer following radiation therapy. Detailed knowledge of the pathologic features of recurrent prostate cancer in radical prostatectomy specimens will help to optimize the design of focal (subtotal) therapies currently under investigation.
Design: We analyzed the radical prostatectomy specimens (RPS) from 50 patients who underwent salvage radical prostatectomy following radiation therapy between 1994 and 2008.
Results: Patients' median age at surgery was 68 yrs (range 45-75). The median interval from radiation therapy to surgery was five yrs (range 1-13 yrs). The median pre-salvage serum PSA was 3.40 ng/ml (range 0.20-39.20 ng/ml). Unifocal tumors were present in 66% of the RPS. In 64% of the RPS the tumor(s) were exclusively of peripheral zone origin. Multifocal tumors of peripheral and transition zone origin were present in 22% of the RPS. The tumor was bilateral in 74% (37/50) of the cases. Bilateral involvement was due to extension of tumor across the midline in 29 RPS (58%), with or without a separate contralateral tumor focus in 8 and 21 RPS, respectively. Bilateral independent tumor foci were present in 8 (16%) of the RPS. Tumors extended from the apex to the base in 51% of the cases. Overall, involvement of the apical and base regions by prostate cancer was present in 71% and 65% of the RPS, respectively. The Gleason score was 7(4+3) in 21 and 8 in 23 cases. Therapy effect precluded grading in 6 cases. The pathologic stage was pT2: 24; pT3a:8 and pT3b:18. Six patients had nodal metastases. A positive margin was present in 8 (16%) of the RPS with the majority of the positive margins occurring in patients with seminal vesicle invasion (7/8, 87%). The median tumor volume was 0.960 cc (range 0.051-10.320 cc).
Conclusions: Recurrent prostate cancer following radiotherapy is frequently bilateral with involvement of the apex and base of the prostate. These findings represent challenges that must be taken into account in the design of appropriate templates for focal salvage therapies, as well as in the identification of optimal candidates for these therapies.
Category: Genitourinary (including renal tumors)

Monday, March 9, 2009 9:30 AM

Poster Session I Stowell-Orbison/Autopsy Award # 110, Monday Morning