Presentation Authors: Maxwell Towe*, Linda M. Huynh, Farouk M. El-Khatib, Mohamad Osman, Faysal A. Yafi, Thomas Ahlering, Orange, CA
Introduction: The role of testosterone in prostate growth and the development of prostate cancer is a controversial topic. Most current data suggest that lower testosterone leads to higher grade conversion, whereas higher testosterone may serve a protective role in preventing both development and recurrence. We seek to analyze whether free testosterone (FT) values can predict aggressiveness in prostate cancers.
Methods: We retrospectively reviewed 830 patients who presented to a single surgeon for evaluation and management of prostate cancer. FT values were obtained on each patient at initial visit. All patients underwent radical prostatectomy and samples from surgery were sent for grading and staging. Mean FT values for each Gleason score and stage were calculated and compared by in univariate and multivariate analysis. Patients were then stratified by FT quartile (25th [less than 4.42 ng/dL], 50th [4.43-5.60 ng/dL], 75th [5.61-6.95 ng/dL], and 100th [greater than 6.96 ng/dL]).
Results: Of 830 patients, 168 (22.2%), 330 (39.8%), 188 (22.7%), 46 (5.5%), and 98 (11.8%) had GS â‰¤3+3, 3+4, 4+3, 4+4, and â‰¥4+5, respectively. Mean FT values were significantly different in univariate analysis (p = 0.008). In terms of stage, 553 (66.1%), 272 (32.5%), and 11 (1.3%) were T2, T3, and T4 at presentation, respectively, and mean FT was also lower in patients with higher stage disease (p = 0.01). Figure 1 depicts proportion of Gleason grade by level of FT. Patients who had a FT level in the lowest quartile (â‰¤4.42 ng/dL) had a higher proportion of Gleason grade group 5 (15.6%) than patients in the highest quartile (â‰¥6.96 ng/dL) (6.2%) (p=0.002)._x000D_
After adjusting for age and PSA in multivariate analysis, lower FT was a significant predictor of high-risk score 9-10 (OR: 0.912, 95% CI: 0.836-0.994, p=0.036). These trends showed strong correlation in pathologic stage (p = 0.057), but larger numbers are needed to gauge effect size.
Conclusions: Based on our data, biochemically low FT may be a risk factor for high grade and high stage cancer. These results have implications for the current recommendations for testosterone therapy, which is contraindicated in men with prostate cancer.