Table 3 Tumor characteristics in relation to self-reported breast-feeding duration
Table 3 | All patients | Nulliparous | Breastfeeding duration of first child ≤12 months | Breastfeeding duration of first child >12 months | Ptrend or Chi-square, P | Total breastfeeding duration ≤12 months | Total breastfeeding duration >12 months | Ptrend or Chi-square, P |
|---|---|---|---|---|---|---|---|---|
n=592 | n=89 | n=476 | n=20 | n=325 | n=178 | |||
n (percent) | n (percent) | n (percent) | n (percent) | n (percent) | n (percent) | |||
pT | ||||||||
0 | 14 (2.4%) | 3 (3.4%) | 10 (2.1%) | 0 | 9 (2.8%) | 2 (1.1%) | ||
1 | 424 (71.6%) | 61 (68.5%) | 347 (72.9%) | 12 (60.0%) | 237 (72.9%) | 126 (70.8%) | ||
2 | 144 (24.3%) | 23 (25.8%) | 111 (23.3%) | 8 (40.0%) | 0.20 | 72 (22.2%) | 49 (27.5%) | 0.47 |
3 | 9 (1.5%) | 2 (2.2%) | 7 (1.5%) | 0 | 6 (1.8%) | 1 (0.6%) | ||
4 | 1 (0.2%) | 0 | 1 (0.2%) | 0 | 1 (0.3%) | 0 | ||
Number of axillary lymph nodes | ||||||||
0 | 368 (62.4%) | 61 (68.5%) | 296 (62.3%) | 9 (47.4%) | 203 (62.7%) | 104 (58.8%) | ||
1-3 | 167 (28.3%) | 21 (23.6%) | 135 (28.4%) | 6 (31.6%) | 0.09 | 95 (29.3%) | 51 (28.8%) | 0.18 |
4+ | 55 (9.3%) | 7 (7.9%) | 44 (9.3%) | 4 (21.1%) | 26 (8.0%) | 22 (12.4%) | ||
Missing | 2 | 0 | 1 | 1 | 1 | 1 | ||
Histologic grade | ||||||||
I | 157 (26.6%) | 22 (24.7%) | 132 (27.8%) | 3 (15.0%) | 87 (26.9%) | 48 (27.0%) | ||
II | 308 (52.1%) | 47 (52.8%) | 248 (52.2%) | 11 (55.0%) | 0.15 | 170 (52.5%) | 91 (51.5%) | 0.86 |
III | 126 (21.3%) | 20 (22.5%) | 95 (20.0%) | 6 (30.0%) | 67 (20.7%) | 39 (21.9%) | ||
Missing | 1 | 0 | 1 | 0 | 1 | 0 | ||
Hormone receptor status | ||||||||
ER+ | 502 (86.7%) | 76 (88.4%) | 407 (87.2%) | 15 (75.0%) | 1df; 0.12 | 273 (85.8%) | 153 (87.4%) | 1df; 0.62 |
ER- | 77 (13.3%) | 10 (11.6%) | 60 (12.8%) | 5 (25.0%) | 45 (14.2%) | 22 (12.6%) | ||
PgR+ | 402 (69.4%) | 61 (70.9%) | 328 (70.2%) | 9 (45.0%) | 1df; 0.02 | 219 (68.9%) | 122 (69.7%) | 1df; 0.85 |
PgR- | 177 (30.6%) | 25 (29.1) | 139 (29.8%) | 11 (55.0%) | 99 (31.1%) | 53 (30.3%) | ||
Missing | 13 | 3 | 9 | 0 | 7 | 3 | ||
ER+ PgR+ | 398 (68.7%) | 60 (69.8%) | 325 (69.6%) | 9 (45.0%) | 1df; 0.02 | 216 (67.9%) | 122 (69.7%) | 1df; 0.68 |
ER+ PgR- | 104 (18.0%) | 16 (18.6%) | 82 (17.6%) | 6 (30.0%) | 1df; 0.16 | 57 (17.9%) | 31 (17.7%) | 1df; 0.95 |
ER- PgR+ | 4 (0.7%) | 1 (1.2%) | 3 (0.6%) | 0 | 1df; 0.72 | 3 (0.9%) | 0 | 1df; 0.20 |
ER- PgR- | 73 (12.6%) | 9 (10.5%) | 57 (12.2%) | 5 (25.0%) | 1df; 0.09 | 42 (13.2%) | 22 (12.6%) | 1df; 0.84 |
Missing | 13 | 3 | 9 | 0 | 7 | 3 |