[The low weight of the prostate is an independent risk factor for positive surgical margins on radical prostatectomy specimens].

Objective: The presence of positive surgical margins (PSM) on radical prostatectomy specimen is predictive of biological recurrence. Our objective was to analyze the influence of prostate weight on surgical margins status after radical prostatectomy.
Patients and Methods: A cohort of 295 patients operated consecutively between 1998 and 2004 at our institution was prospectively studied. The variables significantly associated with the surgical margins status in univariate analysis were used for multivariate analysis.
Results: The overall rate of PSM was 23% (9% for pT2 patients). Parameters significantly associated with surgical margins status were preoperative PSA (p = 0.02), number of positive biopsy cores (p = 0.04), pathological stage (p < 0. 001), and Gleason score on radical prostatectomy specimen (p < 0. 001). In addition, patient age and surgical specimen weight were conversely associated with surgical margins status (p = 0.008 and p = 0.001, respectively). In multivariate analysis, only three parameters were found to be independent factors of PSM: the pathological stage (p < 0. 001), the patient age (p = 0. 02), and the surgical specimen weight (p = 0.02). PSM rates were 6% and 25% in patients with prostate > 70g and < 70g, respectively (p = 0.008), and 15% and 28% in those with prostate weight > or = 50g and < 50g, respectively (p = 0.015).
Conclusion: Low prostate weight is an independent risk factor of PSM. Patients with prostate weight > or = 70g should be considered at low risk of PSM, while those with prostate weight < 50g are at high risk of PSM.