直腸診触知不能のPSA上昇例及びStage A前立腺癌におけるPSA, PSA densityの検討

Abstract

直腸診触知不能のPSA上昇例及びstage A前立腺癌での癌検出率について, PSA, PSA density(PSAD)の比較検討を行い, 更に前立腺肥大症と病期A前立腺癌のPSA transition zone(PSA-TZ)についても検討した.その結果, 前立腺癌検出においてPSADをPSAと併用することは前立腺肥大症に対しての不必要な生検を回避するという点でPSA単独よりも有用と考えられた.又, PSAがgray zoneであれば, PSA-TZ値が前立腺肥大症とstage A前立腺癌の鑑別に有用となる可能性が考えられた

We compared the usefulness of PSA and PSA density (PSAD) in diagnosing prostate cancer in 102 men who had a PSA value higher than 4.0 ng/ml and normal digital rectal examination and who had undergone transrectal ultrasonography-guided systematic sextant biopsies of the prostate between August 1996 and October 1999. In addition, for a group of 53 patients who underwent retropubic simple prostatectomy, PSA, PSAD and PSA transition zone (PSA-TZ) examination results for those with stage A prostate cancer were compared with the results for those with benign prostatic hyperplasia (BPH). Of the former 102 men, 20 (19.6%) had prostate cancer. There was no significant difference in mean PSA level between patients with negative and those with positive biopsy results (mean 9.3 and 11.8, respectively, p = 0.295), but the mean PSAD of patients with positive biopsy results was significantly higher than that of those with negative results (mean 0.55 and 0.29, respectively, p = 0.0007). Of the 53 men who underwent retropubic simple prostatectomy, 10 (18.9%) were diagnosed with stage A prostate cancer. There was no significant difference in mean PSA, PSAD and PSA-TZ examination results between patients with BPH and those with stage A prostate cancer. For all 102 patients and for 71 patients with PSA levels of 4.1-10.0 ng/ml, a PSAD cutoff value of 0.1 reduced the number of biopsies 15.7% (16 of 102 cases), and 22.5% (16 of 71 cases), respectively. These results suggest that by measurement of PSAD some patients with benign disease could be spared a biopsy which would have been performed based on PSA results alone.