The Correlation Between Body Mass Index and Prostate Volume: A Retrospective Analysis of Pre and Postoperative Measurements in Prostate Cancer Patients

Background: This study aims to assess the relationship between body mass index (BMI) and prostate volume, utilizing pre and postoperative measurements. Methods: A retrospective, observational study was conducted at a single site using data from an institutional database. Medical records of patients who underwent robot-assisted radical prostatectomy were reviewed. Data included age, BMI, and prostate volumes measured through digital rectal exam (DRE), transrectal ultrasound (TRUS), magnetic resonance imaging (MRI), and surgical specimen weight (SPW). Results: A total of 168 patients were identified and included in the analysis. Spearman's correlation test revealed a significant association between BMI and prostate volume for all measurement methods, reporting r = 0.146 (p = 0.047) for DRE, r = 0.268 (p < 0.0001) for TRUS, r = 0.177 (p = 0.021) for MRI and r = 0.234 (p = 0.002) for SPW. Linear regression analysis confirmed the significant association between BMI and prostate volume, reporting, respectively, R2 = 0.026 (p = 0.036) for DRE, R2 = 0.076 (p < 0.0001) for TRUS, R2 = 0.038 (p = 0.011) for MRI and R2 = 0.040 (p = 0.009) for SPW. Notably, considering the SPW the best way to estimate prostate volume, for every increase in BMI, the predicted increase of prostate volume is 0.865gr. Conclusions: This study demonstrates a positive linear correlation between BMI and prostate volume, highlighting the importance of considering BMI in prostate volume assessments.