Open AccessThe role of serum testosterone to prostate‐specific antigen ratio as a predictor of prostate cancer risk
Author(s) -
Gurbuz Cenk,
Canat Lutfi,
Atis Gokhan,
Guner Bayram,
Caskurlu Turhan
Publication year - 2012
Publication title -
the kaohsiung journal of medical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.439
H-Index - 36
eISSN - 2410-8650
pISSN - 1607-551X
DOI - 10.1016/j.kjms.2012.01.003
Subject(s) - medicine , prostate cancer , rectal examination , urology , receiver operating characteristic , prostate specific antigen , likelihood ratios in diagnostic testing , transrectal ultrasonography , prostate , testosterone (patch) , cancer , prostate biopsy , area under the curve , gynecology
We analyzed the ratio of serum total testosterone (sTT) to prostate‐specific antigen (PSA) as a predictor of prostate cancer risk. One‐hundred‐four consecutive men with a normal digital rectal examination and a serum PSA level of 2.5–10 ng/ml underwent transrectal ultrasonography‐guided biopsy using a 10‐core scheme. The sTT level was determined before the procedure using a chemiluminescent assay, and the ratio of sTT to PSA (sTT/PSA) was calculated after transforming sTT measurements from ng/dL to ng/mL. The overall cancer detection rate was 17.3%. The median sTT level was 332 ng/dl in men with cancer and 413 ng/dL in those without ( p = 0.032). The median sTT/PSA ratio in these groups was 0.55 and 0.74, respectively ( p = 0.035). The receiver operator characteristic (ROC) method was used to evaluate the properties of the sTT/PSA ratio, with testosterone and PSA as predictors of prostate cancer risk. The accuracy of the sTT/PSA ratio in prostate cancer diagnosis, represented by the area under the curve (AUC), was 0.739 (95% CI 0.640–0.823, p < 0.05). Optimizing the sensitivity and specificity of the sTT/PSA ratio using the ROC provided a cutoff point of 0.60, which corresponded to 82% sensitivity and 62% specificity. When the patients were divided into normal‐ and low‐sTT level groups according to testosterone value (300 ng/dl), the probability of detecting prostate cancer was 3.3‐fold higher in hypogonadal men as compared with eugonadal men. These results support the use of the sTT‐to‐PSA ratio for predicting the risk of prostate cancer and increasing the specificity of PSA measurement.