PROSPECTIVE EVALUATION OF PROSTATE-SPECIFIC ANTIGEN DENSITY AND SYSTEMATIC BIOPSIES FOR EARLY DETECTION OF PROSTATIC-CARCINOMA

Significant controversies persist in regard to the need for systematic biopsies in patients with serum prostate-specific antigen (PSA) level s above 4 ng/mL (Hybritech assay), especially if they show no signs of prostatic cancer on digital rectal examination (DRE) or transrectal u ltrasonography (TRUS). We evaluated 565 consecutive patients referred to us for prostatism, suspicious lesions on DRE, or an elevated serum PSA level. These patients do not represent a purely screened populatio n. A detection rate of 38.4 percent was achieved by performing directe d biopsies of suspicious lesions on DRE and/or TRUS, and systematic bi opsies of all patients with serum PSA levels above 4 ng/mL. Among 142 patients with serum PSA between 4.1 and 10 ng/mL, but without suspicio n for cancer on DRE and TRUS (DRE- TRUS-), a large number of patients (6.2) were subjected to systematic biopsies to detect one cancer. A re ceiver-operating characteristic curve for PSA density (PSAD) applied t o this population confirmed that the best cut-off point for biopsies w as a PSAD of 0.15, below which only two of twenty-three cancers would have been missed, sparing biopsies in 77 of 142 patients. A similar ap proach was applied to DRE- TRUS- patients with serum PSA levels above 10 ng/mL. The number of cancers in those with serum PSA between 10.1 a nd 14 ng/mL was too low to establish a PSAD cut-off point. In patients with serum PSA above 14 ng/mL, the best PSAD cut-off point for biopsi es was 0.3, below which two of thirteen cancers would have been missed , sparing biopsies in 19 of 39 patients. We conclude that PSAD can saf ely reduce the number of patients subjected to systematic biopsies wit hout significantly compromising cancer detection.