Total testosterone density predicts high tumor load and disease reclassification of prostate cancer: results in 144 low-risk patients who underwent radical prostatectomy

Objectives: The aim of this study is to evaluate the association between total testosterone density (TTD), defined as the ratio of serum TT to prostate volume (PV), and high tumor load (HTL) in low-risk prostate cancer (PCA) patients who underwent radical prostatectomy. Materials and methods: Tumor load was defined as the percentage of prostate volume invaded by cancer (PPI-PCA) in the surgical specimen. Pathologic features including tumor upgrading, upstaging or positive surgical margins in the specimen defined unfavorable disease (UD). PSA, TT, PSA density (PSAD), TTD, percentage of biopsy positive cores (BPC), PV and body mass index (BMI). The association of factors with the risk UD and HTL was evaluated by statistical methods. Results: The cohort included 144 consecutive low-risk PCA patients. Overall, 104 patients (72.2%) had at least one feature indicating UD. TTD was associated with BMI, TT, PSA, PV and PPI-PCA ≥ 20% defined as HTL. A higher PPI-PCA was associated with an increased risk of UD with a fair discriminant power (area under the curve, AUC = 0.775; p < 0.0001). Patients with PPI-PCA > 20% were considered the study group versus patients with a PPI-PCA < 20% (control group). BPC, PSAD and TTD were independently associated with the risk of HTL (PPI-PCA ≥ 20%) with receiver-operating characteristics (ROC) curves indicating the same discriminant power for BPC (AUC = 0.628; p = 0.013), PSAD (AUC = 0.611; p = 0.032) and TTD (AUC = 0.610; p = 0.032). Conclusions: Among low-risk PCA patients, TTD is associated with the risk of HTL, which is an independent predictor of UD and should be evaluated in the management of these patients.