Smaller Prostate Size Is Associated with Greater Volume of Disease at Prostatectomy
Boris Gershman, Fei Dong, Douglas M Dahl, Francis J McGovern, Niall M Heney, W Scott McDougal, Chin-Lee Wu. Massachusetts General Hospital, Boston, MA
Background: Smaller prostate size is associated with a number of negative prognostic indicators including higher Gleason score and positive surgical margins. We hypothesized that this may be related to longer time to diagnosis for patients with smaller glands and investigated whether gland size is related to volume of disease at prostatectomy.
Design: A retrospective review was performed of patients with Gleason 6-10 prostate cancer who underwent radical prostatectomy from 2001 through 2010. Patients were identified from a prostatectomy tumor bank database. Univariate and multiple logistic regression were performed to determine association between prostate weight and volume of disease at prostatectomy. Number of quadrants with prostate cancer on surgical pathology was used as a surrogate for volume of disease.
Results: A total of 2054 patients underwent radical prostatectomy. Mean age, PSA, and prostate weight were 59.6 ± 6.6 years, 6.0 ± 4.7 ng/ml, and 45.5 ± 17.5 grams, respectively. Gleason score was 6 in 1055 patients (51.4%), 7 in 858 patients (41.8%), and 8-10 in 141 patients (6.9%). Number of quadrants with prostate cancer was distributed as follows: 1 quadrant in 274 patients (13.3%), 2 quadrants in 557 patients (27.1%), 3 quadrants in 464 patients (22.6%), and 4 quadrants in 759 (37.0%). On one-way analysis of variance, increasing number of quadrants with cancer was associated with decreasing prostate weight (p < 0.001). On univariate and multiple logistic regression (Table 1), smaller prostate weight, higher PSA, and higher Gleason score were associated with increasing volume of disease.
|OR for 2 vs 1 Quadrants||p-value||OR for 3 vs 1 Quadrants||p-value||OR for 4 vs 1 Quadrants||p-value|
|PSA (ng/ml)||1.08||0.001||1.09||0.003||1.16||< 0.001|
|Prostate weight (grams)||0.988||0.003||0.975||< 0.001||0.967||< 0.001|
|7||1.27||0.184||1.93||< 0.001||2.64||< 0.001|