Clinical significance of nonpalpable prostate cancer with favorable biopsyfeatures in Japanese men

Objective: To assess the clinical significance of nonpalpable localized pro state cancers with relatively favorable six sextant biopsy features in Japa nese men. Patients and Methods: 136 nonpalpable prostate cancers of which biopsy feat ures confined to (1) a Gleason score of 6 or less, (2) one or two positive cores per six sextant cores, and (3) 50% or less involvement of any positiv e core were collected. The Gleason score, tumor extension, and cancer volum e were compared with preoperative serum PSA and PSA density for the patient s who underwent radical prostatectomy. PSA doubling time was measured for t he patients who were treated expectantly. Results: Treatments chosen for 136 patients with favorable biopsy features were radical prostatectomy alone for 48 and with preoperative androgen depr ivation for 30, radiation to the prostate for 12, androgen deprivation ther apy for 21, and watchful waiting for 25. Of 48 patients who underwent radic al prostatectomy without androgen deprivation therapy, 25% had nonorgan-con fined cancers. Seven cancers (1 4.6%) were Gleason score of 7, but no cance rs were 8 or greater. Among 42 prostatectomy specimens for which cancer vol ume was measured, 22 (52.4%) had cancer volume >0.5 cm(3). Pretreatment ser um PSA levels were correlated neither with the Gleason score, tumor extensi on nor cancer volume. There was only one nonorgan confined cancer in the 23 cancers for which PSA density was <0.2 ng/ml/g. The ability of PSA density to predict cancer volume (0.5 cm(3) was 0.61 using a cut-off of 0.2 ng/ml/ g. Of the 25 patients treated expectantly, the PSA doubling time was less t han 2 years for 3 patients, while it was stable or fluctuated for 13. Conclusions: Tumor extension can be predicted based on PSA density in nonpa lpable prostate cancer with favorable biopsy features, but predictability o f cancer volume based on PSA or PSA density is not satisfactorily high. New parameters or biomarkers that complement needle biopsy findings are needed to predict clinical significance of Tie prostate cancer with favorable bio psy features, Copyright (C) 2000 S. Karger AG. Basel.