[PSA level of the transitional zone: a new marker especially reliable for the detection of prostatic cancer].

The extensive use of serum prostate specific antigen in early PCa diagnosis has been limited by the far from perfect sensibility and specificity of this test. The value of prostate specific antigen density (PSAD) to enhance prostate cancer detection in patients with PSA serum levels below 10 ng/ml is limited due to controversial results. We have compared the value of PSAD of the transition zone (PSA-T) dividing serum PSA by transition zone volume to the PSAD for early prostate cancer prediction in patients with PSA levels under 10 ng/ml. PSAD and PSA-TZ were calculated in patients with histologically proved located prostate cancer or with benign histology. We have defined a cut-off value of 0.35 ng/ml/cc for PSA-TZ with both a sensitivity and a specificity in predicting prostate cancer of nearly 90%. For PSAD around 0.15 ng/ml/cm3, PSA-TZ value was significant in prostate cancer. This study showed that PSA-TZ could be a new accurate parameter for prostate cancer prediction in patients with PSA below 10 ng/ml.