Table 1 Characteristics of cases and controls
From: DNA methylation in repeat negative prostate biopsies as a marker of missed prostate cancer
Characteristic | Cases (n = 111) | Controls (n = 129) |
|---|---|---|
Age at first biopsy, median years (IQR) (missing: 0) | 66.2 (61.9–70.7) | 65.6 (59.5–69.2) |
Calendar year at first biopsy, median (IQR) (missing: 0) | 2002 (98–04) | 2003 (01–05) |
Time interval between the first and second biopsy, median months (IQR) (missing: 0) | 21.9 (11.9–37.1) | 22.5 (12.7–41.5) |
Time interval between the first biopsy and the index sampling, median months (IQR) (missing: 0) | 44.5 (27.2–74.3) | 45.9 (27.1–73.5) |
Number of patients per ward (%) (missing: 0) | ||
Ward I | 86 (77.5) | 100 (77.5) |
Ward II | 25 (22.5) | 29 (22.5) |
GSTP1 methylation %, median (IQR) | ||
First biopsy (missing: 8 cases, 14 controls) | 3.25 (1.75–5.50) | 2.75 (1.37–4.25) |
Second biopsy (missing: 7 cases, 8 controls) | 3.25 (2.00–6.00) | 2.75 (1.75–3.75) |
Difference between the second and the first biopsy (missing: 14 cases, 20 controls) | 0.00 (− 2.25–2.25) | 0.00 (− 1.00–1.25) |
PITX2 methylation %, median (IQR) | ||
First biopsy (missing: 18 cases, 23 controls) | 8.75 (4.75–11.75) | 8.25 (5.12–11.19) |
Second biopsy (missing: 17 cases, 14 controls) | 8.25 (5.50–12.19) | 9.00 (5.75–12.87) |
Difference between the second and the first biopsy (missing: 30 cases, 30 controls) | − 1.00 (−6.00–5.25) | 0.00 (− 3.62–4.25) |
APC methylation %, median (IQR) | ||
First biopsy (missing: 15 cases, 21 controls) | 1.33 (1.00–3.08) | 1.33 (1.33,3.33) |
Second biopsy (missing: 16 cases, 17 controls) | 1.33 (1.00–3.92) | 1.33 (1.00–3.67) |
Difference between the second and the first biopsy (missing: 29 cases, 33 controls) | 0.00 (−1.33–1.83) | 0.17 (− 0.33–1.42) |
C1orf114 methylation %, median (IQR) | ||
First biopsy (missing: 18 cases, 19 controls) | 4.00 (2.00–8.50) | 2.50 (1.50–5.50) |
Second biopsy (missing: 12 cases, 9 controls) | 5.00 (1.50–9.25) | 4.50 (1.50–7.12) |
Difference between the second and the first biopsy (missing: 28 cases, 23 controls) | 0.00 (− 3.25–4.50) | 0.50 (− 2.00–4.50) |
GABRE methylation %, median (IQR) | ||
First biopsy (missing: 27 cases, 38 controls) | 2.70 (1.00–6.30) | 2.00 (1.00–4.90) |
Second biopsy (missing: 28 cases, 25 controls) | 2.60 (1.00–5.50) | 1.90 (1.00–5.20) |
Difference between the second and the first biopsy (missing: 44 cases, 51 controls) | − 0.20 (−1.90–2.40) | 0.00 (− 2.00–1.80) |
LINE-1 methylation %, median (IQR) | ||
First biopsy (missing: 5 cases, 7 controls) | 69.7 (66.0–74.0) | 69.3 (66.3–72.6) |
Second biopsy (missing: 3 cases, 3 controls) | 69.3 (66.2–72.1) | 69.0 (66.1–73.0) |
Difference between the second and the first biopsy (missing: 24 cases, 30 controls) | 0.00 (− 3.33–4.00) | 0.17 (− 4.00–4.08) |
Gleason score (missing: 2 cases) | ||
6 | 28 (25.7) | – |
3 + 4 | 53 (48.6) | – |
4 + 3 | 13 (11.9) | – |
8+ | 15 (13.8) | – |
PSA at the second biopsy, median (IQR) (missing: 22 cases, 19 controls) | 9.15 (6.02–13.00) | 8.00 (6.00–10.16) |