Efficiency of prostate-specific antigen and digital rectal examination in screening, using 4.0 ng/ml and age-specific reference range as a cutoff forabnormal values

BACKGROUND. The purpose of this study was to examine the diagnostic efficie ncy of prostate-specific antigen (PSA) and digital rectal examination (DRE) testing when using either 4.0 ng/ml or an age-specific reference range (AS RR) as an abnormal cutoff PSA value. METHODS. Between 1992-1995, 116,073 men, aged 40-79 years, were screened du ring Prostate Cancer Awareness Week. When using a 4.0-ng/ml cutoff PSA valu e, 22,014 had either an abnormal PSA, an abnormal DRE, or both. When using an ASRR cutoff PSA value, 17,561 had either an abnormal PSA, an abnormal DR E, or both. The positive predictive value (PPV), sensitivity, and specifici ty of PSA, DRE, and combined PSA and DRE tests were evaluated. RESULTS. When using a 4.0-ng/ml cutoff PSA value, the PPVs of abnormal PSA alone, abnormal DRE alone, and combined abnormal PSA and DRE tests were 27. 7%, 17.7%, and 56.0%, respectively. Sensitivities were 34.9%, 27.1%, and 38 .0%, respectively. Specificities were 63.1%, 49.0%, and 87.9%, respectively . When using an ASRR cutoff PSA value, the PPVs of each category were 31.8% , 20.8%, and 63.7%, respectively. Sensitivities were 27.1%, 41.0%, and 31.8 %, respectively. Specificities were 75.0%, 32.8%, and 92.2%, respectively. The PPVs of the PSA test were higher than those of the DRE. The PPVs of com bined tests were highest when using either a 4.0-ng/ml cutoff PSA value or an ASRR cutoff PSA value (all P < 0.001). When using an ASRR, the PPVs of P SA, DRE, and combined tests were higher than those when using a 4.0-ng/ml w ithout statistical significance (all P> 0.05). Sensitivity of PSA when usin g an ASRR was lower than when using 4.0 ng/ml. CONCLUSIONS. Significantly higher PPVs indicated that utilizing both a PSA test and a DRE is most effective in screening for the early detection of pr ostate cancer. Although higher PPVs when using an ASRR cutoff PSA value sug gested fewer unnecessary biopsies, lower sensitivities resulted in fewer ca ncers detected. Thus, we recommend that the combination of a PSA test with a cutoff value of 4.0 ng/ml and a DRE should continue to be utilized in the screening programs. (C) 1999 Wiley-Liss, Inc.