Table 1.
Baseline Characteristics of Low- and Intermediate-Risk Prostate Cancer Patients in the National Prostate Cancer Register and of Cases and Controls in the ProMort Study, Sweden, 1998–2011
| Variable | NPCR | ProMort | ||||||
|---|---|---|---|---|---|---|---|---|
| Died From PC (n = 1,735) | Did Not Die From PC (n = 56,217) | Cases (n = 1,710) | Controls (n = 1,710) | |||||
| No. | % | No. | % | No. | % | No. | % | |
| Year of diagnosis | ||||||||
| 1998–2000 | 591 | 34.06 | 5,377 | 9.56 | 578 | 33.80 | 578 | 33.80 |
| 2001–2004 | 751 | 43.29 | 14,339 | 25.51 | 741 | 43.33 | 741 | 43.33 |
| 2005–2008 | 336 | 19.37 | 19,239 | 34.22 | 334 | 19.53 | 334 | 19.53 |
| 2009–2011 | 57 | 3.28 | 17,262 | 30.71 | 57 | 3.33 | 57 | 3.33 |
| Age at diagnosis, yearsa | 73.75 (7.75) | 67.21 (7.99) | 73.73 (7.75) | 67.62 (7.76) | ||||
| Age group at diagnosis, years | ||||||||
| ≤55.0 | 29 | 1.67 | 3,168 | 5.64 | 29 | 1.70 | 80 | 4.68 |
| 55.1–65.0 | 205 | 11.82 | 19,731 | 35.10 | 200 | 11.70 | 568 | 33.22 |
| 65.1–75.0 | 699 | 40.29 | 23,725 | 42.20 | 690 | 40.35 | 756 | 44.21 |
| >75.0 | 802 | 46.22 | 9,593 | 17.06 | 791 | 46.26 | 306 | 17.89 |
| Gleason score | ||||||||
| ≤6 | 948 | 54.64 | 39,114 | 69.58 | 927 | 54.21 | 1,328 | 77.66 |
| 7 | 787 | 45.36 | 17,103 | 30.42 | 783 | 45.79 | 382 | 22.34 |
| Tumor stage | ||||||||
| T1 | 2 | 0.12 | 58 | 0.10 | 2 | 0.12 | 2 | 0.12 |
| T1a | 76 | 4.38 | 2,829 | 5.03 | 75 | 4.39 | 119 | 6.96 |
| T1b | 94 | 5.42 | 1,366 | 2.43 | 92 | 5.38 | 51 | 2.98 |
| T1c | 534 | 30.78 | 33,104 | 58.89 | 521 | 30.47 | 854 | 49.94 |
| T2 | 1,029 | 59.31 | 18,860 | 33.55 | 1,020 | 59.65 | 684 | 40.00 |
| PSA level, ng/mLa | 10.36 (4.56) | 7.99 (4.08) | 10.36 (4.58) | 8.77 (4.29) | ||||
| PSA category, ng/mL | ||||||||
| <4.0 | 116 | 6.69 | 7,239 | 12.88 | 116 | 6.78 | 176 | 10.29 |
| 4.0–9.9 | 754 | 43.46 | 33,659 | 59.87 | 740 | 43.27 | 933 | 54.56 |
| ≥10.0 | 865 | 49.86 | 15,319 | 27.25 | 854 | 49.94 | 601 | 35.15 |
| Follow-up time, yearsb | 5.87 (3.58–8.57) | 5.55 (3.08–8.35) | 5.86 (3.59–8.51) | 9.86 (7.56–12.09) | ||||
| Cause of censoringc,d | ||||||||
| Death | ||||||||
| Prostate cancer | 1,735 | 100.00 | 1,710 | 100.00 | 80 | 4.68 | ||
| Other causes | 7,968 | 14.17 | 262 | 15.32 | ||||
| Administrativee | 48,249 | 85.83 | 1,368 | 80.00 | ||||
| Initial treatment | ||||||||
| Conservative | 798 | 46.80 | 20,804 | 37.87 | 785 | 46.70 | 648 | 38.53 |
| Curative | 412 | 24.16 | 29,653 | 53.98 | 407 | 24.21 | 849 | 50.48 |
| Noncurative | 495 | 29.03 | 4,476 | 8.15 | 489 | 29.09 | 185 | 11.00 |
| Missing data | 30 | 1,284 | 29 | 28 | ||||
Abbreviations: NPCR, National Prostate Cancer Register; PC, prostate cancer; ProMort, Prognostic Factors for Mortality in Prostate Cancer; PSA, prostate-specific antigen.
a Values are expressed as mean (standard deviation).
b Values are expressed as median (25th–75th percentile range).
c No right-censoring was assumed in the study because of the very low percentage (0.23%) of loss to follow-up.
d For ProMort controls, censoring refers to follow-up after sampling into the ProMort study.
e Administrative censoring occurred on December 31, 2012.