MP51-06 EVALUATION OF LENGTH, MAXIMUM GLEASON SCORE, AND EXTENSION OF DISEASE AT POSITIVE SURGICAL MARGINS DURING RADICAL PROSTATECTOMY

INTRODUCTION AND OBJECTIVES: A positive surgical margin (PSM) following radical prostatectomy (RP) for prostate cancer is known to affect subsequent recurrence and survival. The extent of PSM in addition to other pathologic parameters, have also been shown to significantly impact clinical outcomes. We examined the effect of length, extent of disease and maximum Gleason score at PSM on oncologic outcomes. METHODS: A retrospective review of 3971 patients undergoing RP for prostate cancer at USC between 1978 2009 revealed 1053 patients with PSM, out of whom 814 received no neoadjuvant or adjuvant hormone therapy. The initial 360 patients were selected to maximize available follow-up data, and their pathology slides were rereviewed for following parameters: length of PSM (mm), maximum Gleason score at PSM, and maximal extension of PSM (intraprostatic incision vs. extracapsular extension). Data was available in 269 patients who are the subject of this study. Stepwise multivariable Cox regression models were used to evaluate the impact of the above PSM features as well as age, preoperative PSA, pathologic Gleason score, pathologic stage and adjuvant radiation therapy on biochemical and clinical recurrence-free survival (RFS), and overall survival (OS). RESULTS: Median follow-up was 11.6 years. Maximum extension of PSM was limited to intraprostatic incision in 195 (73%) and extracapsular extension in 74 (27%) patients. The median length of PSM was 4 mm (range 1-55 mm); 119 (44%) 4mm. The maximum Gleason score at PSM was 7 in 105 (39%) patients. 10-yr PSA RFS, clinical RFS, and OS were 71%, 90%, and 84%, respectively. Multivariable Cox regression modeling showed the length of PSM 4mm and extracapsular extension at PSM are independently associated with PSA and clinical recurrence after RP. These findings can help decision-making regarding adjuvant therapy in patients with PSM and should be reported by pathologists. PSA RFSHR PSA RFS-P value Clinical RFSHR Clinical RFS-P value Overall SurvivalHR Overall Survival-P value