Table 3 Risk of breast cancer subgroups defined by immunohistochemical markers in relation to total duration of breastfeeding
From: Breastfeeding in relation to risk of different breast cancer characteristics
Tumour subgroup | Breastfeeding total in months | Number of cases | Incidence/100000 | RR | RR* |
|---|---|---|---|---|---|
Ki67 low | |||||
(≤10%)# | <4.0 | 54 | 182 | 1.00 | 1.00 |
≥4.0 - <8.0 | 76 | 203 | 1.11 (0.78 - 1.57) | 1.06 (0.74 - 1.51) | |
≥8.0 - <13.0 | 72 | 201 | 1.09 (0.77 - 1.56) | 1.01 (0.69 - 1.47) | |
≥13.0 | 58 | 165 | 0.90 (0.62 - 1.31) | 0.82 (0.53 - 1.25) | |
Missing | 11 | 183 | --- | --- | |
Total | 271 | 188 | p-trend:0.54 | p-trend:0.44 | |
Ki67 high | |||||
(>10%) | <4.0 | 17 | 57 | 1.00 | 1.00 |
≥4.0 - <8.0 | 21 | 56 | 0.98 (0.51 - 1.85) | 1.02 (0.53 - 1.96) | |
≥8.0 - <13.0 | 26 | 72 | 1.25 (0.68 - 2.31) | 1.39 (0.72 - 2.67) | |
≥13.0 | 30 | 85 | 1.48 (0.82 - 2.69) | 1.88 (0.94 - 3.76) | |
Missing | 7 | 116 | --- | --- | |
Total | 101 | 70 | p-trend:0.11 | p-trend:0.03 | |
HER2 (0-1+)# | |||||
<4.0 | 57 | 192 | 1.00 | 1.00 | |
≥4.0 - <8.0 | 78 | 208 | 1.08 (0.77 - 1.52) | 1.02 (0.72 - 1.45) | |
≥8.0 - <13.0 | 84 | 234 | 1.21 (0.86 - 1.69) | 1.12 (0.78 - 1.61) | |
≥13.0 | 73 | 207 | 1.07 (0.76 - 1.52) | 1.07 (0.72 - 1.59) | |
Missing | 19 | 499 | --- | --- | |
Total | 311 | 216 | p-trend:0.58 | p-trend:0.44 | |
HER2 (2 + -3+) | |||||
<4.0 | 9 | 30 | 1.00 | 1.00 | |
≥4.0 - <8.0 | 9 | 24 | 0.80 (0.32 - 2.01) | 1.02 (0.39 - 2.65) | |
≥8.0 - <13.0 | 11 | 31 | 1.02 (0.42 - 2.46) | 1.40 (0.53 - 3.69) | |
≥13.0 | 11 | 31 | 1.03 (0.43 - 2.49) | 1.35 (0.46 - 3.97) | |
Missing | 1 | 17 | --- | --- | |
Total | 41 | 28 | p-trend:0.79 | p-trend:0.59 | |
Cyclin D1 low | |||||
(≤10%) # | <4.0 | 54 | 182 | 1.00 | 1.00 |
≥4.0 - <8.0 | 82 | 219 | 1.20 (0.85 - 1.69) | 1.15 (0.81 - 1.64) | |
≥8.0 - <13.0 | 73 | 203 | 1.11 (0.78 - 1.58) | 1.05 (0.72 - 1.53) | |
≥13.0 | 73 | 122 | 1.14 (0.80 - 1.62) | 1.06 (0.71 - 1.60) | |
Missing | 13 | 216 | --- | --- | |
Total | 295 | 205 | p-trend:0.65 | p-trend:0.77 | |
Cyclin D1 high | |||||
(>10%) | <4.0 | 14 | 47 | 1.00 | 1.00 |
≥4.0 - <8.0 | 14 | 37 | 0.79 (0.37 - 1.65) | 0.84 (0.39 - 1.78) | |
≥8.0 - <13.0 | 24 | 67 | 1.38 (0.72 - 2.68) | 1.56 (0.77 - 3.19) | |
≥13.0 | 20 | 57 | 1.19 (0.60 - 2.36) | 1.61 (0.73 - 3.56) | |
Missing | 6 | 100 | --- | --- | |
Total | 78 | 54 | p-trend:0.29 | p-trend:0.10 | |
P27 low | |||||
(≤10%) # | <4.0 | 21 | 71 | 1.00 | 1.00 |
≥4.0 - <8.0 | 41 | 109 | 1.55 (0.91 - 2.62) | 1.56 (0.91 - 2.67) | |
≥8.0 - <13.0 | 31 | 86 | 1.22 (0.70 - 2.12) | 1.21 (0.68 - 2.18) | |
≥13.0 | 35 | 99 | 1.40 (0.82 - 2.41) | 1.35 (0.73 - 2.50) | |
Missing | 7 | 116 | --- | --- | |
Total | 135 | 94 | p-trend:0.47 | p-trend:0.61 | |
P27 high | |||||
(>10%) | <4.0 | 48 | 162 | 1.00 | 1.00 |
≥4.0 - <8.0 | 53 | 141 | 0.87 (0.59 - 1.29) | 0.83 (0.55 - 1.24) | |
≥8.0 - <13.0 | 65 | 181 | 1.11 (0.76 - 1.61) | 1.04 (0.70 - 1.56) | |
≥13.0 | 53 | 151 | 0.93 (0.63 - 1.37) | 0.93 (0.59 - 1.46) | |
Missing | 11 | 183 | --- | --- | |
Total | 230 | 159 | p-trend:0.95 | p-trend:0.73 |