Table 6.
Adjusted odds ratios and 95% confidence intervals for the associations between selected tumor clinicopathological characteristics and parity and breastfeeding
| Characteristic | Parous/nulliparous | Parous vs. nulliparous | Ever/never | Ever vs. never breastfed | ||
|---|---|---|---|---|---|---|
| OR (95% CI) | P | OR (95% CI) | P | |||
| p53 expression | ||||||
| p53− | 1877/94 | 1.00 (reference) | 1537/234 | 1.00 (reference) | ||
| p53+ | 2015/75 | 1.51 (1.10, 2.09) | 0.01 | 1511/216 | 1.11 (0.90, 1.36) | 0.32 |
| Breast cancer subtype | ||||||
| Luminal A-like | 1937/78 | 1.00 (reference) | 1519/225 | 1.00 (reference) | ||
| Luminal B-like/HER2− | 697/35 | 0.78 (0.51, 1.22) | 0.28 | 511/92 | 0.84 (0.63, 1.11) | 0.22 |
| Luminal B-like/HER2+ | 551/28 | 0.88 (0.55, 1.39) | 0.58 | 421/67 | 1.02 (0.75, 1.39) | 0.88 |
| HER2-enriched | 249/14 | 0.86 (0.45, 1.65) | 0.65 | 211/27 | 1.31 (0.83, 2.08) | 0.24 |
| TNBC | 458/14 | 1.31 (0.65, 2.61) | 0.45 | 386/39 | 1.52 (0.98, 2.37) | 0.06 |
| CK5/6 expression | ||||||
| CK5/6− | 3430/153 | 1.00 (reference) | 2679/406 | 1.00 (reference) | ||
| CK5/6+ | 462/16 | 1.68 (0.90, 3.13) | 0.10 | 369/44 | 1.36 (0.90, 2.37) | 0.14 |
| EGFR expression | ||||||
| EGFR− | 2855/119 | 1.00 (reference) | 2244/333 | 1.00 (reference) | ||
| EGFR+ | 1037/50 | 0.67 (0.43, 1.04) | 0.07 | 804/117 | 0.77 (0.57, 1.05) | 0.10 |
Note: Odds ratios (ORs) and 95% confidence intervals (CIs) were obtained from multivariate logistic regression models separately for parity and breastfeeding that were mutually adjusted for p53, breast cancer subtype, CK5/6 and EGFR, in addition to age, BMI, and age at menarche