Do Tumor Volume, Tumor Volume Ratio, Type of Nerve Sparing and Surgical Experience Affect Prostate Specific Antigen Recurrence After Laparoscopic Radical Prostatectomy? A Matched Pair Analysis

Abstract

We assessed the impact of tumor volume, tumor volume ratio (tumor volume-to-prostate volume), surgical experience and type of nerve sparing procedure on biochemical recurrence after laparoscopic radical prostatectomy. Of 1,600 laparoscopic radical prostatectomies performed between March 1999 and May 2006 we evaluated 555 patients who had at least 24 months of followup and received neither neoadjuvant nor adjuvant therapy. Of 555 patients 81 had biochemical recurrence and were match paired in 3 groups with those without recurrence. Matching decisions were based on factors such as age, preoperative prostate specific antigen, pathological stage, Gleason score, surgical margin status with localization, tumor volume, type of nerve sparing procedure, surgeon and date of operation that are related to surgical experience. We evaluated the impact of tumor volume and tumor volume ratio, type of nerve sparing procedure and surgeon on biochemical recurrence, and excluded the factor being investigated in each matched pair. Tumor volumes were 3.58 vs 3.3 cc and tumor volume ratios were 0.081 vs 0.071 in the biochemical recurrence and no biochemical recurrence groups, respectively (p=0.026 and p=0.040). At the second match pair the numbers of nonnerve sparing, unilateral and bilateral nerve sparing procedures were 65, 12 and 4 vs 62, 13 and 6, respectively, without statistical significance. At the last match pair the volume of cases for the first generation and the other generations were 56 and 25 vs 59 and 22, respectively, also without statistical significance. Although surgical experience based on an adequate training program and type of nerve sparing procedure do not have a significant impact on biochemical recurrence, tumor volume and tumor volume ratio do.