The relationship of prostate-specific antigen to digital rectal examination and transrectal ultrasonography. Findings of the American Cancer Society National Prostate Cancer Detection Project.

The participating institutions of the American Cancer Society National Prostate Cancer Detection Project did 520 biopsies on 2425 men over a 3.5-year period. A total of 88 cancers were confirmed pathologically, 93% of which clinically were organ confined. In 324 men (62.3%), a recommendation for biopsy was made based solely on the results of transrectal ultrasonography (TRUS); in 69 patients (13.3%), solely on the digital rectal examination (DRE); in 116 patients (22.3%), on abnormal DRE and TRUS examinations; and in 11 patients (2.1%), in whom DRE and TRUS were normal, on elevated prostate-specific antigen (PSA) levels. The TRUS was abnormal in 80.6% of men found to have cancer, and the PSA level and DRE were abnormal for 67% and 50% of cancers, respectively. The influence of PSA level on cancer detection increased as the serum level increased above 4 ng/ml. The positive predictive values of both the DRE and TRUS were influenced significantly by the presence of an elevated PSA level (P = 0.044 and P less than 0.001, respectively). The results of this ongoing multicenter study support the following statements: (1) the prostate cancer detection rate is influenced by this diagnostic triad and (2) the detection rate of organ-confined disease can be improved substantially by early detection programs.