168 TABLE 1. Predictive factors in the cancer and the non-cancer group with PSA value of less than 4 ng/ml No. of patients Age (yr) Prostate volume (cc) PSA (ng/ml) PSAD (ng/ml/cc) %fPSA IPSS Qmax (ml/sec) DRE (＋) TRUS (＋) Total 292 63.1±9.9 37.3±15.7 2.9±0.8 0.08±0.04 0.23±0.54 15.6±7.6 15.16±31.5 36.9% (34/292) 31.5% (92/292) Cancer 28 66.9±7.4 33.8±16.3 3.0±0.8 0.10±0.05 0.18±0.06 17.8±6.7 12.8±5.1 14.2% (4/28) 42.8% (12/28) Non-cancer 264 62.7±10.1 37.7±15.7 2.9±0.8 0.08±0.04 0.23±0.57 15.4±7.6 15.4±33.0 11.3% (30/264) 30.3% (80/264) PSA: prostate-specific antigen, PSAD: PSA density, %fPSA: percent free PSA, IPSS: International Prostate Symptom Score, Qmax: maximal flow rate, DRE: digital rectal examination, TRUS: transrectal ultrasonography, a: statistically significant (p＜0.05) TABLE 2. Cancer detection rates according to PSA level, age, and age-adjusted PSA level with PSA value of less than 4 ng/ml PSA (ng/ml) No. of patients No. cancer patients Detection rate (%) 　A Pearson’s chi-square test was performed to see if the PSA level was higher than the age-adjusted PSA levels in the patients with a PSA ≤4 ng/ml. The test results were 57.1% (16/28) in the prostate cancer group and 64.7% (171/264) in the non-prostate-cancer group, which showed no significant difference (p=0.852). 　The detection rate of prostate cancer was 9.6% in the pa- tients with PSA ≤4 ng/ml. When the PSA level was divided into ranges of 0-0.9 ng/ml, 1.0-1.9 ng/ml, 2.0-2.9 ng/ml, and 3.0-4.0 ng/ml, the detection rates were 10%, 5.7%, 8.2%, and 11.1%, respectively, which showed no statistically sig- nificant difference. In addition, when the patients’ ages were divided into groups of 59 years or less, 60-69 years, and 70 years or more, the detection rates were 4.6%, 12%, and 10.9%, respectively. No statistically significant differ- ence was found among the detection rates. However, as shown in Table 2, the detection rate was higher in the pa- tients aged 60 years or more than in the other age brackets. In addition, the detection rate for patients whose PSA was higher than age-adjusted PSA was 8.5% (Table 2). 　When the PSA level was divided into ranges of 0.0-1.9 ng/ml, 2.0-2.9 ng/ml, and 3.0-4.0 ng/ml, followed by the con- duct of a univariate analysis between the prostate cancer group and the non-prostate-cancer group, mean age was significantly higher in the prostate cancer group with a PSA range of 2.0-2.9 ng/ml (64.7 vs. 71.5 years old, p= 0.049), whereas prostate volume was smaller (39.0 cc vs. 26.9 cc, p=0.028) and the PSAD was higher (0.07 vs. 0.09, p=0.042) than in the non-prostate-cancer group. No sig- nificant difference in the variables was found in the PSA ranges of 0.0-1.9 ng/ml and 3.0-4.0 ng/ml, respectively, however (Table 3). The results of the multivariate analysis of the PSA range of 2.0-2.9 ng/ml showed that the statisti- cally significant predictive factors of prostate cancer in a prostate needle biopsy were the patient’s age and prostate volume (p=0.028 and 0.014, respectively; odds ratio=1.200 and 0.845, respectively). 　The variables that were statistically significant in the univariate or multivariate analysis in the PSA range of Korean J Urol 2011;52:166-171 Kim et al 0.034a 0.178 0.558 0.061 0.624 0.112 0.688 0.648 0.178 10 5.7 8.2 11.1 4.6 12 10.9 9.6 8.5 0-0.9 1.0-1.9 2.0-2.9 3.0-4.0 Age (yr) ＜59 60-69 70＜ Total ≥Age-adjusted PSA PSA: prostate-specific antigen 2.0-2.9 ng/ml, such as the patient’s age, prostate volume, and PSAD, were analyzed by ROC curve. The AUCs of each factor were 0.691 (95% CI: 0.582-0.787), 0.813 (95% CI: 0.714-0.890), and 0.749 (95% CI: 0.643-0.837), respectively (Fig. 1). No AUC showed a significant difference. At the cut- off value of 36 cc for prostate volume, sensitivity and specif- icity were 92.4% and 50.0%, respectively, and at the cutoff value of 35 cc, sensitivity and specificity were 85.7% and 51.3%, respectively. At the cutoff value of 0.066 for PSAD, sensitivity and specificity were 90.1% and 54.1%, respec- tively, and at the cutoff value of 0.070, sensitivity and spe- cificity were 85.7% and 57.7%, respectively. The criteria for prostate volume and PSAD, which set the sensitivity of the diagnosis of prostate cancer as 90% or higher by the ROC curve analysis, were a prostate volume ≤36 cc and a PSAD ≥0.06 ng/ml/cc. DISCUSSION Screening tests such as PSA measurement, DRE, and p-value Univariate Multivariate 10 35 85 162 86 133 73 292 187 0.033a 0.212 0.559 0.057 0.623 0.110 0.689 0.882 0.252 1 2 7 18 4 16 8 28 16