Table 2.
Summary of findingsa
| Exposure | Pooled OR (95% CI) for TNBC | Heterogeneity I2 (P value) | # Studies | #TNBC cases |
|---|---|---|---|---|
| Reproductive Risk Factors | ||||
| Parity (≥3 live births/0 live births) | 0.99 (0.80, 1.24) | 73% (<.001) | 18 | 2466 |
| Breastfeeding (Yes/No) | 0.80 (0.66, 0.98) | 74% (<.001) | 8 | 2924 |
| Duration of breastfeeding (≥12 m/0 m) | 1.02 (0.59, 1.76) | 92% (<.001) | 7 | 1294 |
| Age at menarche (≥14 yr/<12 yr) | 0.87 (0.80, 0.95) | 0% (.96) | 9 | 2546 |
| Age at first live birth (≥30 yr/<20 yr) | 0.78 (0.64, 0.96) | 38% (.15) | 9 | 1404 |
| Hormone use | ||||
| OC use (Yes/No) | 1.16 (0.92, 1.46) | 62% (.04) | 6 | 1310 |
| Duration of OC use (≥10 yr/0 yr) | 1.29 (1.08, 1.55) | 0% (.93) | 4 | 747 |
| MHT use (Yes/No) | 1.05 (0.92, 1.21) | 0% (.15) | 5 | 952 |
| Other Factors | ||||
| Family history (Yes/No) | 1.55 (1.34, 1.81) | 56% (<.001) | 12 | 3442 |
| Alcohol (Yes/No) | 1.23 (0.94, 1.60) | 25% (.25) | 4 | 461 |
| Smoking (Yes/No) | 0.97 (0.88, 1.07) | 0% (.88) | 5 | 1804 |
| BMI (≥30/<25) | 1.12 (0.89, 1.42) | 73% (<.001) | 12 | 1848 |
| Breast density (≥75%/≤25%) | 2.19 (1.67, 2.88) | 0% (0.74) | 4 | 231 |
a
CI = confidence intervals; TNBC = triple negative breast cancer; BMI = body mass index; OC = oral contraceptive; MHT = menopausal hormone therapy.