Table 1.
Cohort | Classifier | Subtype | N | % |
---|---|---|---|---|
Healthy | Age | 34.2 years (28–40) | 12 | 100% |
Milk stagea | Colostrum | 0 | 0% | |
Transitional | 0 | 0% | ||
Mature | 12 | 100% | ||
Breast cancer cases | Age | 36.2 years (25–48) | 19 | 100% |
pT | 1 | 5 | 26% | |
2 | 8 | 42% | ||
3 | 5 | 26% | ||
4 | 1 | 5% | ||
pN | 0 | 9 | 47% | |
≥1 | 10 | 53% | ||
M | 0 | 18 | 95% | |
1 | 1 | 5% | ||
Stage | I | 2 | 11% | |
II | 11 | 58% | ||
III | 5 | 26% | ||
IV | 1 | 5% | ||
HR | Positive | 16 | 84% | |
Negative | 3 | 16% | ||
HER2 | Positive | 1 | 5% | |
Negative | 18 | 95% | ||
Molecular subtypeb | Luminal A | 6 | 32% | |
Luminal B | 9 | 47% | ||
HER2+ | 1 | 5% | ||
TNBC | 3 | 16% | ||
Diagnosis timec | PrBC | 10 | 53% | |
PPBC | 9 | 47% | ||
Histologic subtype | IDC | 15 | 79% | |
ILC | 4 | 21% | ||
Milk stagea | Colostrum | 3 | 21% | |
Transitional | 1 | 7% | ||
Mature | 11 | 79% |
NOTE: Healthy and breast cancer–diagnosed individuals are described in detail.
Abbreviations: HR, hormone receptor; IDC, invasive ductal carcinoma; ILC, invasive lobular carcinoma; PR, progesterone receptor; TNBC, triple-negative breast cancer.
aMilk stage is defined as colostrum: 0–5 days after childbirth; transitional: 6–14 days after childbirth; and mature: after 14 days from childbirth.
bMolecular subtype is based on IHC: luminal A is defined as ER- or PR-positive, HER2-negative, and Ki-67 <20%; luminal B is defined as ER- or PR-positive, HER2-negative, and Ki-67 ≥20%; and HER2+ is defined as HER2-positive regardless of ER, PR, and Ki-67 status. TNBC is defined as ER-, PR-, and HER2-negative.
cDiagnosis time refers to breast cancer diagnosed during pregnancy (PrBC) or postpartum (PPBC).