Does size matter? the significance of prostate size on pathologic and functional outcomes in patients undergoing robotic prostatectomy

Background: We examined the effect of prostate weight on perioperative data, and the pathological and functional outcomes of robotic-assisted laparoscopic prostatectomy (RALP). Patients and methods: Data were available from 716 consecutive patients before, during and after undergoing RALP at one institution. Prostate size was arbitrarily stratified by recorded prostate weight into <50, 50-80 and >80 g, corresponding to small, moderate and large glands, respectively. Perioperative data and the histopathological and functional outcomes were compared across these groups by both univariable and multivariable-adjusted analyses. Results: Increased prostate size was associated with increased age, preoperative prostate-specific antigen levels, body mass index, operative duration, blood loss, lower biopsy and pathological Gleason scores, and lower pathological staging (P < 0.05). The incidence of extensive positive surgical margins was 14.8%, 9.7%, and 5.3% in small, moderate and large prostates, respectively (P < 0.001). However, after multivariable adjustment, only Gleason score and pathological stage were significantly associated with the incidence of positive margins (P < 0.05); prostate weight was not significantly associated. Overall, 78% and 92% of patients were potent and continent at 12 months, respectively, which was not affected by prostate size. Conclusion: Patients with larger prostates had favourable pathological outcomes after RALP. When controlling for pathological stage, prostate size was not associated with margin positivity. Functionally, neither continence nor potency at 12 months was affected by prostate size.