Table 1.
Characteristics of men in the ProtecT study cohort*
| EDTA anticoagulated blood plasma | Serum | |||||
|---|---|---|---|---|---|---|
| Characteristics | No cancer detected n = 3032, 64% No. (%) |
Diagnosed with cancer n = 1733, 36% No. (%) |
P | No cancer detected n = 1221, 66%No. (%) |
Diagnosed with cancer n = 639, 34% No. (%) |
P |
| Clinical characteristics | ||||||
| Age (IQR), y | 62 (58 to 66) | 63 (59 to 67) | <.001 | 62 (58 to 66) | 63 (59 to 67) | .005 |
| Prior PSA screen | 629 (21) | 232 (13) | <.001 | 207 (17) | 83 (13) | .024 |
| Unknown | 63 (2.1) | 35 (2.0) | 27 (2.2) | 13 (2.0) | ||
| Total PSA (IQR), ng/mL | 4.3 (3.6 to 5.7) | 5.4 (3.9 to 8.6) | <.001 | 4.5 (3.6 to 5.8) | 5.6 (4.2 to 9.7) | <.001 |
| Free PSA (IQR), ng/mL | 1.00 (0.76 to 1.37) | 0.97 (0.70 to 1.46) | .3 | 0.97 (0.71 to 1.35) | 0.92 (0.68 to 1.46) | .7 |
| Intact PSA (IQR), ng/mL | 0.40 (0.27 to 0.58) | 0.41 (0.26 to 0.66) | .095 | 0.38 (0.25 to 0.57) | 0.43 (0.27 to 0.70) | <.001 |
| hK2, ng/mL | 0.043 (0.030 to 0.062) | 0.049 (0.035 to 0.073) | <.001 | 0.041 (0.029 to 0.061) | 0.053 (0.036 to 0.081) | <.001 |
| Tumor characteristics | ||||||
| Gleason sum score | ||||||
| ≤ 6 | 1099 (63) | 464 (73) | ||||
| 7 | 542 (31) | 143 (22) | ||||
| ≥ 8 | 92 (5.3) | 32 (5.0) | ||||
| Stage | ||||||
| T1 | 1016 (59) | 330 (52) | ||||
| T2 | 331 (19) | 88 (14) | ||||
| T3 | 127 (7.3) | 63 (10) | ||||
| T4 | 4 (0.2) | 2 (0.3) | ||||
| Unknown | 255 (15) | 156 (24) | ||||
* The cohort underwent a 10-core prostate biopsy and had EDTA-anticoagulated plasma and/or serum available for retrospective measurements of total, free, and intact prostate-specific antigens (PSAs) and hK2, in cryopreserved sample aliquots. Data are median (interquartile range) or frequency (percentage). IQR = interquartile range; hK2 = human kallikrein-related peptidase 2; PSA = prostate-specific antigen.