Table 4.
Associations between mitochondrial DNA integrity (ND4/ND1 divided by ND1/nuclear genome) and breast cancer risk
| Stratum | mtDNA integritya | Controls | Cases | OR | 95% CI | p value |
|---|---|---|---|---|---|---|
| Overall | Quartile 1 (0.34–0.90) | 129 | 152 | Reference | ||
| Quartile 2 (0.90–1.00) | 126 | 102 | 1.06 | (0.68–1.66) | 0.79 | |
| Quartile 3 (1.00–1.11) | 133 | 142 | 1.56 | (0.95–2.56) | 0.08 | |
| Quartile 4 (1.11–2.59) | 130 | 142 | 1.20 | (0.69–2.08) | 0.52 | |
| Continuous variable | 519 | 539 | 1.07 | (0.75–1.52) | 0.73 | |
| ER+ | Quartile 1 (0.34–0.90) | 129 | 20 | Reference | – | – |
| Quartile 2 (0.90–1.00) | 126 | 50 | 1.61 | (0.78–3.35) | 0.20 | |
| Quartile 3 (1.00–1.11) | 133 | 79 | 2.59 | (1.19–5.66) | 0.02 | |
| Quartile 4 (1.11–2.59) | 130 | 89 | 2.47 | (1.05–5.80) | 0.04 | |
| Continuous variable | 519 | 238 | 1.54 | (0.87–2.72) | 0.14 | |
| ER− | Quartile 1 (0.34–0.90) | 129 | 128 | Reference | – | – |
| Quartile 2 (0.90–1.00) | 126 | 40 | 0.98 | (0.55–1.74) | 0.94 | |
| Quartile 3 (1.00–1.11) | 133 | 47 | 1.22 | (0.62–2.39) | 0.56 | |
| Quartile 4 (1.11–2.59) | 130 | 41 | 0.96 | (0.46–2.00) | 0.92 | |
| Continuous variable | 519 | 256 | 0.99 | (0.63–1.54) | 0.95 |
ER Estrogen receptor, mtDNA Mitochondrial DNA
aAnalyses are adjusted for age, body mass index, smoking, center of origin, and plate