Table 4 Association of estrogen receptor status and reproductive and family history variables
Reproductive and family history characteristics | ER-positive or borderline tumors (n = 95) | ER-negative tumors (n = 87) | ORa | 95% CI | P |
|---|---|---|---|---|---|
Age at menarche (years)b | |||||
<12 | 16 (17.0) | 19 (22.4) | 1.0 (ref) | ||
≥ 12 | 78 (83.0) | 66 (77.6) | 0.7 | 0.3–1.5 | 0.42 |
Age at first full-term pregnancy (years) | |||||
No full-term pregnancies | 27 (28.4) | 27 (31.0) | 1.0 (ref) | ||
<20 | 10 (10.5) | 16 (18.4) | 1.5 | 0.6–4.0 | 0.43 |
20–24 | 26 (27.4) | 19 (21.8) | 0.7 | 0.3–1.6 | 0.39 |
25–29 | 23 (24.2) | 16 (18.4) | 0.7 | 0.3–1.7 | 0.45 |
30–34 | 9 (9.5) | 9 (10.3) | 1.2 | 0.4–3.6 | 0.80 |
Trend | 1.0 | ||||
Total live births | |||||
0 | 27 (28.4) | 27 (31.0) | 1.0 (ref) | ||
1–2 | 57 (60.0) | 49 (56.3) | 0.9 | 0.4–1.7 | 0.68 |
3 or more | 11 (11.6) | 11 (12.6) | 1.0 | 0.3–2.8 | 0.97 |
Trend | 0.86 | ||||
Total miscarriages (gravid women) | |||||
0 | 61 (80.3) | 42 (65.6) | 1.0 (ref) | ||
1 or more | 15 (19.7) | 22 (34.4) | 2.1 | 1.0–4.6 | 0.05 |
Total induced abortions (gravid women) | |||||
0 | 48 (63.2) | 44 (68.8) | 1.0 (ref) | ||
1 or more | 28 (26.8) | 20 (31.2) | 0.7 | 0.4–1.5 | 0.42 |
Breastfeeding (parous women) | |||||
Never | 12 (17.6) | 29 (48.3) | 1.0 (ref) | ||
Ever | 56 (82.4) | 31 (51.7) | 0.2 | 0.1–0.5 | <0.001 |
Months between last full-term pregnancy and diagnosis | |||||
No full-term pregnancy | 27 (28.4) | 27 (31.0) | 1.0 (ref) | ||
0–23 | 19 (20.0) | 16 (18.4) | 0.9 | 0.4–2.0 | 0.71 |
≥ 24 | 49 (51.6) | 44 (50.6) | 0.9 | 0.4–1.8 | 0.77 |
Trend | 0.78 | ||||
Oral contraceptive use | |||||
Never | 19 (20.0) | 12 (13.8) | 1.0 (ref) | ||
Ever | 76 (80.0) | 75 (86.2) | 1.6 | 0.7–3.4 | 0.28 |
Total months of oral contraceptive usec | |||||
None | 19 (20.2) | 12 (14.6) | 1.0 (ref) | ||
1–35 | 24 (25.5) | 23 (28.0) | 1.1 | 0.5–2.6 | 0.81 |
36–83 | 16 (17.0) | 20 (24.4) | 1.5 | 0.6–3.7 | 0.42 |
84 or more | 35 (37.2) | 27 (32.9) | 0.9 | 0.4–2.1 | 0.85 |
Trend | 0.78 | ||||
Family history of breast or ovarian cancerd | |||||
No family history | 75 (79.8) | 71 (82.6) | 1.0 (ref) | ||
Mother or sister | 19 (20.2) | 15 (17.4) | 0.9 | 0.4–1.9 | 0.72 |