Investigative clinical study on prostate cancer part II: on the role of the pretreatment total PSA to free testosterone ratio as a marker assessing prostate cancer prognostic groups after radical retropubic prostatectomy.

Objectives: To explore the significance of the pretreatment total prostate-specific antigen (PSA) to free testosterone (FT) ratio (PSA/FT) as a marker for assessing the pathologic Gleason sum (pGS) and levels of tumor extension (pT) in prostatectomy specimens.

Patients And Methods: 128 of 135 consecutive patients diagnosed with prostate cancer underwent radical prostatectomy. Simultaneous pretreatment serum samples were obtained to measure serum total testosterone, FT and total PSA levels. The statistical design of the study included 2 sections: the first part trying to explore the role of the PSA/FT ratio in clustering patients with different pathologic prognostic factors, and the second to investigate the PSA/FT ratio distribution in different groups of patients according to the pathologic stage and pGS of the specimen after radical prostatectomy.

Results: The average age was 65.80 (range 51.21-77.26) years, mean PSA was 8.88 (range 1.22-44.27) μg/l, mean FT was 35.32 (range 13.70-69.30) pmol/l, and the mean PSA/FT ratio was 0.27 (range 0.04-1.48). The PSA/FT ratio significantly clustered both the pT and pGS groups. Analysis of variance for the distribution of the PSA/FT ratio was significant for the pT model groups. The mean PSA/FT ratio increased as the tumor extended and grew through the prostate gland (high-stage disease). Analysis of variance for the different distributions of the PSA/FT ratio was significant for all model pGS groups. In our investigation we also found (data not shown) that a PSA/FT ratio of ≥0.40 was strongly correlated with large extensive (pT3b+pT4) and high-grade cancers (pGS8+pGS9).

Conclusions: Prostate cancer patients may be classified into 3 different pathologic prognostic groups according to the PSA/FT ratio: low risk (PSA/FT ≤0.20), intermediate risk (PSA/FT >0.20 and ≤0.40), and high risk (PSA/FT >0.40 and ≤1.5). The PSA/FT ratio may be considered as the marker expressing different biology groups of prostate cancer patients, and it is strongly associated with pT and pGS.