Serum Total Testosterone Is a Significant Preoperative Variable Independently Contributing to Separating the Prostate Cancer Population into Prostatectomy Gleason Score Groups

Abstract

Aim: To investigate the potential of preoperative serum total testosterone (TT) in contributing to the definition of separate prostatectomy Gleason score (pGS) groups of the prostate cancer (PCa) population. Materials and Methods: The data of 220 patients operated on for PCa were retrospectively reviewed. No patient had previously received 5α-reductase inhibitor, luteinizing hormone-releasing analogs or testosterone replacement treatment. The patient population was grouped according to the pGS as 6 = 3+3, 7 = 3+4, 7 = 4+3 and 8-10. Eight variables were simultaneously investigated in each group: prostate-specific antigen (PSA), TT, free testosterone, age, percentage of positive prostate biopsy cores (P+), biopsy Gleason score (bGS), overall cancer volume estimated as percentage of prostate volume (V+) and prostate weight (Wi). Univariate analysis of variance (ANOVA), multivariate analysis of variance (MANOVA) and multivariate discriminant analysis (MDA) were the statistical methods used for evaluating the data. Results: There were 89 patients in pGS 6 = 3+3, 84 in pGS 7 = 3+4, 24 in pGS 7 = 4+3 and 23 in pGS 8-10. ANOVA showed that bGS (p < 0.0001), P+ (p < 0.0001), V+ (p < 0.0001), PSA (p = 0.0001), Wi (p = 0.0002) and TT (p = 0.01) were significantly different in the four pGS groups. MANOVA tests showed that only bGS (p < 0.0001), V+ (p = 0.0003), TT (p = 0.001) and, to a lesser extent, PSA (p = 0.06) were the significant variables that individually and independently contributed a significant amount to separation of the four pGS groups of the PCa population. MDA showed that the independent variables ranked as bGS (p < 0.0001), TT (p = 0.001), V+ (p = 0.001) and PSA (p = 0.06). Conclusions: Serum TT is a significant preoperative variable that independently contributes to separating the PCa population into pGS score groups. Pretreatment baseline serum TT levels should be measured and their inclusion in neural networks predicting PCa natural history be considered in the patient population diagnosed with PCa.