Table 1.
Clinical parameters of the study population, stratified by risk diabetes and metformin use
| Diabetes + Metformin + (n = 126) |
Diabetes + Metformin - (n = 144) |
Diabetes - Metformin - (n = 2,028) |
p | All patients (n = 2,298) |
|||||
|---|---|---|---|---|---|---|---|---|---|
| Continuous parameters | Median | Mean ± SD | Median | Mean ± SD | Median | Mean ± SD | Median | Mean± SD | |
| Age (y) | 66.2 | 65.9 ± 6.0 | 69.2 | 68.0 ± 6.5 | 65.8 | 65.1 ± 7.4 | < 0.001 | 65.9 | 65.3 ± 7.4 |
| Follow-up (y) | 7.2 | 7.5 ± 3.3 | 8.0 | 8.1 ± 3.4 | 8.3 | 8.5 ± 3.8 | 0.005 | 8.3 | 8.5 ± 3.8 |
| Pre-treatment PSA | 6.7 | 7.6 ± 5.5 | 6.4 | 8.1 ± 5.0 | 6.2 | 7.9 ± 6.0 | 0.843 | 6.2 | 7.9 ± 6.0 |
| Gleason score | 7.0 | 6.8 ± 0.9 | 7.0 | 6.9 ± 1.0 | 7.0 | 6.7 ± 0.9 | 0.076 | 7.0 | 6.7 ± 0.9 |
| % positive biopsies | 33.3 | 36.6 ± 24.7 | 33.3 | 39.5 ± 25.3 | 33.3 | 36.7 ± 24.8 | 0.426 | 33.3 | 36.9 ± 24.8 |
| BMI | 30.0 | 30.5 ± 5.4 | 29.8 | 30.5 ± 5.1 | 27.5 | 28.2 ± 4.4 | < 0.001 | 27.8 | 28.4 ± 4.6 |
| Prostate volume (cm3) | 31.2 | 31.7 ± 8.5 | 32.5 | 32.9 ± 9.9 | 31.9 | 32.3 ± 9.3 | 0.537 | 31.8 | 32.3 ± 9.3 |
| Planning volume (cm3) | 59.9 | 60.0 ± 12.6 | 60.6 | 60.9 ± 14.2 | 60.4 | 60.2 ± 13.5 | 0.799 | 60.4 | 60.2 ± 13.5 |
| V100 | 98.3 | 97.6 ± 2.5 | 98.0 | 96.7 ± 3.8 | 97.9 | 96.5 ± 4.6 | 0.038 | 97.9 | 96.6 ± 4.4 |
| V150 | 72.7 | 71.3 ± 8.8 | 72.3 | 68.6 ± 12.2 | 70.8 | 68.1 ± 13.0 | 0.022 | 70.9 | 68.3 ± 13.0 |
| V200 | 42.6 | 41.6 ± 9.0 | 41.3 | 39.4 ± 11.1 | 40.6 | 38.9 ± 11.7 | 0.037 | 40.8 | 39.1 ± 11.5 |
| D90 (%) | 121.1 | 120.9 ± 10.2 | 120.5 | 118.9 ± 11.2 | 118.9 | 118.9 ± 12.4 | 0.222 | 119.0 | 119.0 ± 12.3 |
| Most recent PSA | < 0.02 | 0.03 ± 0.07 | < 0.02 | 0.03 ± 0.09 | < 0.02 | 0.03 ± 0.10 | 0.967 | < 0.02 | 0.03 ± 0.09 |
| Categorical parameters | n | (%) | n | (%) | n | (%) | p | n | (%) |
| Tobacco | |||||||||
| Never | 51 | (40.5) | 48 | (33.3) | 815 | (40.2) | 0.350 | 914 | (39.8) |
| Former | 59 | (46.8) | 74 | (51.4) | 887 | (43.7) | 1,020 | (44.4) | |
| Current | 16 | (12.7) | 22 | (15.3) | 326 | (16.1) | 364 | (15.8) | |
| PNI | |||||||||
| No | 79 | (62.7) | 85 | (59.0) | 1421 | (70.1) | 0.006 | 1,585 | (69.0) |
| Yes | 47 | (37.3) | 59 | (41.0) | 607 | (29.9) | 713 | (31.0) | |
| Hypertension | |||||||||
| No | 38 | (30.2) | 35 | (24.3) | 1,070 | (52.8) | < 0.001 | 1,143 | (49.7) |
| Yes | 88 | (69.8) | 109 | (75.7) | 958 | (47.2) | 1,155 | (50.3) | |
| NCCN risk group | |||||||||
| Low | 47 | (37.3) | 46 | (32.39) | 812 | (70.0) | 0.402 | 907 | (39.5) |
| Intermediate | 61 | (48.4) | 71 | (49.3) | 955 | (47.1) | 1,087 | (47.3) | |
| High | 18 | (14.3) | 25 | (17.4) | 261 | (12.9) | 304 | (13.2) | |
| Clinical stage | |||||||||
| T1b-T2a | 114 | (90.5) | 123 | (85.4) | 1,786 | (88.1) | 0.438 | 2023 | (88.0) |
| T2b-T3c | 12 | (9.52) | 21 | (14.6) | 242 | (11.9) | 275 | (12.0) | |
| CAD | |||||||||
| No | 96 | (76.2) | 108 | (75.0) | 1,7090 | (84.3) | 0.001 | 1,913 | (83.2) |
| Yes | 30 | (23.8) | 36 | (25.0) | 319 | (15.7) | 385 | (16.8) | |
| Isotope | |||||||||
| Pd | 117 | (92.9) | 130 | (90.3) | 1,776 | (87.6) | 0.144 | 2023 | (88.0) |
| I | 9 | (7.1) | 14 | (9.7) | 252 | (12.4) | 275 | (12.0) | |
| XRT | |||||||||
| No | 66 | (52.4) | 58 | (40.3) | 1019 | (50.2) | 0.058 | 1,143 | (49.7) |
| Yes | 60 | (47.6) | 86 | (59.7) | 1009 | (49.8) | 1,145 | (50.3) | |
| Hypercholesterolemia | |||||||||
| No | 52 | (41.3) | 76 | (52.8) | 1,392 | (68.6) | < 0.001 | 1,520 | (66.1) |
| Yes | 74 | (58.7) | 68 | (47.2) | 636 | (31.4) | 778 | (33.9) | |
| ADT | |||||||||
| 0 months | 82 | (65.1) | 89 | (61.8) | 1,3675 | (67.4) | 0.713 | 1,538 | (66.9) |
| ≤ 6 months | 26 | (20.6) | 32 | (22.2) | 389 | (19.2) | 447 | (19.4) | |
| > 6 months | 18 | (14.3) | 23 | (16. 0) | 272 | (13.4) | 313 | (13.7) | |
| Testosterone* | |||||||||
| Low | 76 | (76.8) | 64 | (72.7) | 871 | (66.7) | 0.022 | 1011 | (67.8) |
| Normal | 22 | (22.2) | 21 | (23.92) | 318 | (24.4) | 361 | (24.2) | |
| High | 1 | (1.0) | 3 | (3.4) | 116 | (8.9) | 120 | (8.04) | |
*
Not all patients had testosterone values.
PSA – prostate-specific antigen, BMI – body mass index, PNI – perineural invasion, CAD – computer-assisted detection, XRT – external beam radiation therapy, ADT – adrogen deprivation therapy