Table 1.
Characteristics of the study cohort (n=5220)
| Variables | PSA (ng ml−1) | The whole cohort | ||
|---|---|---|---|---|
| 4.0–10.0 | 10.1–20.0 | Above 20.0 | ||
| Age at time of biopsy (year) | ||||
| Mean±s.d. | 66.4±8.5 | 68.9±8.5 | 70.6±8.2 | 68.4±8.7 |
| Median (IQR) | 67.0 (61.0–73.0) | 69.0 (69.0–70.0) | 71.0 (71.0–72.0) | 69.0 (63.0–75.0) |
| PSA at time of biopsy (ng ml−1) | ||||
| Mean±s.d. | 7.18±1.64 | 13.79±2.82 | 119.85±248.01 | 43.00±145.61 |
| Median (IQR) | 7.20 (5.80–8.60) | 13.30 (11.30–15.90) | 41.70 (39.30–44.20) | 12.00 (7.50–24.50) |
| Prostate volume (ml) | ||||
| Mean±s.d. | 51.0±27.2 | 58.7±33.4 | 55.5±37.6 | 54.2±32.7 |
| Median (IQR) | 44.2 (32.1–63.0) | 49.7 (33.9–77.0) | 44.3 (43.5–46.2) | 45.0 (32.2–68.0) |
| PSA density (ng ml−2) | ||||
| Mean±s.d. | 0.18±0.10 | 0.33±0.83 | 2.87±7.98 | 1.03±4.58 |
| Median (IQR) | 0.15 (0.11–0.22) | 0.27 (0.17–0.41) | 1.06 (0.99–1.12) | 0.26 (0.14–0.59) |
| %fPSA | ||||
| Mean±s.d. | 0.16±0.08 | 0.15±0.07 | 0.13±0.09 | 0.15±0.09 |
| Median (IQR) | 0.15 (0.11–0.20) | 0.14 (0.10–0.19) | 0.11 (0.10–0.11) | 0.14 (0.09–0.20) |
| Transrectal ultrasound, n (%) | ||||
| Positive (+) | 244 (13.7) | 220 (14.0) | 340 (21.5) | 902 (17.3) |
| Negative (−) | 1532 (86.3) | 1346 (86.0) | 1241 (78.5) | 4318 (82.7) |
PSA: prostate-specific antigen; %fPSA: the ratio of free-to-total PSA; s.d.: standard deviation; IQR: interquartile range