Obesity does not correlate with adverse pathologic findings on transperineal template-guided mapping biopsy of the prostate.

Background: Obesity has correlated with adverse pathologic features on prostate biopsy and may predispose to a higher rate of prostate cancer-related death after radical prostatectomy. In this study, we examine the potential relationship between body mass index (BMI) and histopathologic findings on transperineal template-guided mapping biopsy of the prostate (TTMB).

Methods: From January 2005 to January 2008, 244 consecutive patients underwent TTMB using an anatomic-based technique. The criteria for TTMB included previously negative transrectal ultrasound (TRUS) biopsy with persistently elevated PSA and/or diagnosis of ASAP, or HG-PIN. The study population was divided into 4 different BMI cohorts (BMI < 25, BMI 25-29.9, BMI 30-34.9, and BMI ≥ 35 kg/m(2)). Biopsy findings were compared between the various BMI cohorts using one-way analysis of variance (ANOVA) and the χ(2) test.

Results: Pre-TTMB clinical parameters, including PSA and prostate volume, were not significantly different between the various BMI cohorts. On average, the study population had undergone 1.7 TRUS biopsies before TTMB. Of the 244 study patients, 112 (45.9%), were diagnosed with prostate adenocarcinoma on TTMB. There was no difference in the rate of cancer detection between the different BMI cohorts. Among patients diagnosed with prostate cancer, BMI did not correlate with Gleason score or percent of positive biopsy cores. When the geography of biopsy-positive cores was analyzed, there were no statistically significant differences in cancer location among the different BMI groups.

Conclusions: In this study, obesity did not predispose toward higher Gleason score, larger cancer volume, or geographic cancer distribution on repeat biopsy with TTMB.