Both prospective and retrospective series have explored risk factors for developing aggressive prostate cancer. Predictors of higher grade disease include 5-alpha reductase inhibitor use, older age, and African American background. There is a paucity of literature that has applied similar risk factors to the current model of unfavorable intermediate and high risk disease. This study reports demographic and pharmacologic predictors of being treated for unfavorable intermediate and high risk prostate cancer at a busy academic center. A total of 3445 patients were treated for prostate cancer where baseline demographics, pharmacologic history, and clinicopathologic features were available. The mean age was 67.8 years (41, 93) with a mean PSA of 9.23ng/ml (0.3, 205). 34.2%, 31.7%, 19.1%, and 15.0% of patients were diagnosed with Gleason 6 (3+3), Gleason 7 (3+4), Gleason 7 (4+3), and Gleason 8-10 prostate cancer. The Zumsteg Classification System was applied to categorize patients into low (28.6%), favorable intermediate (22.6%), unfavorable intermediate (30.8%), and high risk (18.0%) disease groups. Unfavorable Prostate Cancer (UPC) was defined as being diagnosed with unfavorable intermediate or high risk disease (48.8%). Univariate and multivariate logistic regression was used to determine those factors that portended for UPC. 64.5% of patients taking 5-alpha reductase medication were diagnosed with UPC, compared to 53.6% of those who did not take this class of medication (p<.0001). This finding was also seen in men who took metformin compared to those who did not (62.4% vs. 53.4%, p<.0001). Men older than age 65 had a higher risk of presenting with UPC compared to younger men (47.8% vs. 34.6%, p<.0001), as did those with a first degree relative who had been diagnosed with prostate cancer (52% vs. 48.1%, p<.0001). Asian men had a higher risk of aggressive disease than men who self-identified as white or African American (72.4% vs. 51.2% and 52.3%, respectively, p<.0001). Men with a comorbidity of HIV were also more likely to exhibit UPC (68.8% vs. 54.4%, p<.0001). On multivariate analysis, older age (OR 2.021, CI 1.735-2.354, p<.0001), the use of 5-alpha reductase inhibitors (OR 2.508, CI 1.228-5.122, p=.012) or metformin (OR 1.334, CI 1.033-1.722, p=.037), and Asian American background (OR 2.481, CI 1.001-6.146, p=.05) predicted for being treated for UPC. In a large hospital series, nearly half of those treated for prostate cancer were diagnosed with UPC. Consistent with previous phase 3 data correlated with higher grade disease, 5-alpha reductase inhibitor use was associated with UPC in this cohort. In keeping with retrospective published series, older men had a higher risk of being treated with more aggressive disease. While prostate cancer is less common in Asian Americans and metformin’s role in prostate cancer therapeutics remains investigational, diagnosis with either classification was associated with UPC in this series.
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