Impact of prostate size on pathologic outcomes and prognosis after radical prostatectomy

Purpose: We investigated prostate size and its correlation with final pathologic outcomes and prognosis.

Materials and methods: From 1993 to 2009, 830 consecutive patients who underwent radical prostatectomy with follow-up duration of 12 months or more were included in this study. Patients were categorized according to prostate size as follows: group 1, prostate size ≤40 g (n=458), and group 2, prostate size >40 g (n=472). Preoperative parameters and postoperative pathologic outcomes were compared between groups. Multivariate analysis with Cox proportional hazards regression model was used to identify the pathologic and clinical factors affecting biochemical recurrence.

Results: Patients in group 1 had higher pathologic T stage (pT2a=17.7% vs. 23.9%, pT2b=1.1% vs. 0%, pT2c=40.4% vs. 39.8%, pT3a=29.5% vs. 21.0%, pT3b=10.7% vs. 13.2%, p=0.003) and higher positive surgical margin (40.3% vs. 33.1%, p=0.033) than did patients in group 2. Pathologic Gleason score was not significantly different between the two groups. The 5-year biochemical-recurrence-free survival was 62.3% for patients in group 1 and 73.2% for patients in group 2 (p=0.005). Multivariate Cox regression analysis showed that prostate size of 40 g or less (hazard ratio [HR], 1.378; 95% confidence interval [CI], 1.027 to 1.848; p=0.032), extracapsular extension (HR, 1.592; 95% CI, 1.147 to 2.209; p=0.005), positive surgical margin (HR, 2.348; 95% CI, 1.701 to 3.242; p<0.001), and pathologic Gleason sum (HR, 1.507; 95% CI, 1.292 to 1.758; p<0.001) were independent predictors of biochemical recurrence.

Conclusions: Smaller prostate size was associated with increased risk of higher pT stage and positive surgical margin after radical prostatectomy. Also, prostate size less than 40 g was an independent prognostic factor for biochemical recurrence.