Table 5. Distribution of mtDNA copy number among subgroups of PCa patients stratified by different levels of clinicopathological characteristics.
| Variable | mtDNA high, No. (%)a | mtDNA low, No. (%)a | OR (95% CI)b | P value |
| PSA, ng/ml | ||||
| <10 | 16 (13.2) | 8 (11.1) | 1 (reference) | |
| 10∼20 | 11 (9.1) | 7 (9.7) | 0.66(0.17–2.58) | 0.545 |
| ≥20 | 94 (77.7) | 57 (79.2) | 0.55(0.20–1.53) | 0.253 |
| P trend | 0.908 | |||
| AJCC stagec | ||||
| II A + II B | 11 (9.2) | 18 (25.4) | 1(reference) | |
| III | 23 (19.3) | 14 (19.7) | 2.93(1.01–8.50) | 0.049 |
| IV | 85 (71.4) | 39 (54.9) | 3.38(1.33–8.57) | 0.010 |
| P trend | 0.009 | |||
| Gleason scored | ||||
| 5–6 | 29 (24.6) | 29 (40.8) | 1(reference) | |
| 7 | 45 (38.1) | 21 (29.6) | 1.80(0.83–3.92) | 0.136 |
| 8–10 | 44 (37.3) | 21 (29.6) | 1.61(0.73–3.53) | 0.237 |
| P trend | 0.063 |
Abbreviations: mtDNA = mitochondrial DNA; PCa = prostate cancer; OR = odds ratio; CI = confidence intervals; PSA = prostate-specific antigen; AJCC = American Joint Committee on Cancer.
a
mtDNA copy number was grouped based on the median mtDNA copy number in controls.
b
Analyses were performed using unconditional models adjusted for age, PSA level, AJCC stage and Gleason score where appropriate.
c
Data of AJCC stage were classified by the 7th AJCC staging system; data were not available for 3 cases.
d
Data of Gleason score were not available for 4 cases.