Oncology - Prostate
Introduction & Objective : When patients with high risk clinically localized prostate cancer seek definitive treatment, urologists can face prognostic challenges regarding the risk of disease recurrence. A larger volume of disease identified on diagnostic prostate biopsy may place patients at increased risk for recurrence following radical prostatectomy, and this could have an important impact on preoperative counseling. This study seeks to explore the relationship between Gleason 4+4 tumor volume on diagnostic prostate biopsy and postoperative disease recurrence after robot-assisted radical prostatectomy (RARP).
Methods : All consecutive patients who underwent RARP at a single academic referral center between November 2009 and February 2016 for biopsy-proven Gleason 4+4 prostate cancer were reviewed retrospectively. Patients were assigned to high-volume (HVD) or low-volume disease (LVD) groups, with HVD defined as 4 or more cores showing Gleason 4+4 cancer on standard 12-core biopsy. Pathologic findings including extracapsular extension (ECE), seminal vesicle invasion (SVI), disease volume on surgical pathology, and positive surgical margins were tracked. Chi-square test and Fisher’s exact test were employed to determine associations between pathologic findings and clinical outcomes in each group where appropriate
A total of 52 identified patients met inclusion criteria, including 19 with LVD and 33 with HVD preoperatively. ECE was present on surgical pathology in 54.5% of patients with HVD versus only 15.8% with LVD (p=0.006), while SVI was present in 27.3% of HVD patients and 0% of those with LVD (p=0.018). No patients demonstrated pathologic lymph node involvement. Biopsy volume predicted biochemical persistence (BCP), present in 5.3% of LVD patients and 30.3% of HVD patients (p=0.033). 85.7% of those with BCP or biochemical recurrence (BCR) over the first 3 years postoperatively were classified as HVD; 76.2% of these patients underwent salvage radiation therapy and 47.6% initiated androgen deprivation therapy. In the available follow-up, 3 patients (5.8%) developed bone metastases and 1 patient died from metastatic disease. Positive surgical margins, final Gleason score on surgical pathology, and the incidence of BCR did not differ statistically between groups<./p>
Our analysis suggests that a higher biopsy volume of Gleason 4+4 disease is correlated with adverse pathologic outcomes after RARP. These patients unsurprisingly face a higher incidence of disease recurrence postoperatively. Patients with LVD may have a better chance of cure with RARP than predicted based upon their Gleason score alone.