Table 3.
Association between GSTP1 methylation (considered as a continuous variable, per each 1% increase) and the risk of prostate cancer detection stratified by Gleason score and ward
| GSTP1 | ORs of prostate cancer for methylation level in the second biopsy | ORs of prostate cancer for the highest† methylation level between the first and second biopsy | ||
|---|---|---|---|---|
| OR1 (95% CI) | OR2 (95% CI) | OR1 (95% CI) | OR2 (95% CI) | |
| Gleason score | ||||
| 6 or 3 + 4 | 1.14 (1.02 to 1.27) | 1.10 (0.97 to 1.25) | 1.19 (1.06 to 1.35) | 1.18 (1.03 to 1.34) |
| at least 4 + 3 | 1.33 (1.08 to 1.62) | 1.22 (0.96 to 1.57) | 1.27 (1.07 to 1.51) | 1.21 (0.98 to 1.48) |
| ward | ||||
| Ward I (86 cases, 100 controls) | 1.17 (1.03 to 1.32) | 1.13 (0.99 to 1.30) | 1.19 (1.06 to 1.34) | 1.17 (1.03 to 1.33) |
| Ward II (25 cases, 29 controls) | 1.26 (0.96 to 1.66) | 1.08 (0.77 to 1.52) | 1.61 (1.04 to 2.49) | 1.58 (0.92 to 2.71) |
OR odd ratio, CI confidence interval
OR1 adjusted for matching variables (ward and time distance between the first biopsy and the index sampling)
OR2 adjusted for the matching variables, age and year at the first biopsy and prostatic specific antigen (PSA) at the second biopsy (continuous variables are centered at their mean)
†For example, if methylation in GSTP1 is 4% in the first biopsy and 7% in the second biopsy, the highest level used for this analysis is 7%