Table 4 Risk of breast cancer subgroups defined by type and receptor status 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* |
|---|---|---|---|---|---|
Ductal# | |||||
<4.0 | 59 | 199 | 1.00 | 1.00 | |
≥4.0 - <8.0 | 74 | 197 | 0.99 (0.70 - 1.39) | 0.99 (0.70 - 1.41) | |
≥8.0 - <13.0 | 74 | 206 | 1.03 (0.73 - 1.45) | 1.04 (0.72 - 1.51) | |
≥13.0 | 79 | 224 | 1.12 (0.80 - 1.58) | 1.20 (0.81 - 1.78) | |
Missing | 12 | 199 | --- | --- | |
Total | 298 | 207 | p-trend:0.45 | p-trend:0.26 | |
Lobular | |||||
<4.0 | 15 | 51 | 1.00 | 1.00 | |
≥4.0 - <8.0 | 21 | 56 | 1.11 (0.57 - 2.15) | 0.95 (0.48 - 1.88) | |
≥8.0 - <13.0 | 23 | 64 | 1.27 (0.66 - 2.43) | 1.02 (0.51 - 2.04) | |
≥13.0 | 14 | 40 | 0.79 (0.38 - 1.63) | 0.65 (0.29 - 1.45) | |
Missing | 9 | 150 | --- | --- | |
Total | 82 | 57 | p-trend:0.63 | p-trend:0.44 | |
Tubular | |||||
<4.0 | 4 | 13 | 1.00 | 1.00 | |
≥4.0 - <8.0 | 10 | 27 | 1.97 (0.62 - 6.29) | 2.09 (0.64 - 6.89) | |
≥8.0 - <13.0 | 7 | 20 | 1.43 (0.42 - 4.89) | 1.59 (0.43 - 5.91) | |
≥13.0 | 6 | 17 | 1.26 (0.36 - 4.47) | 1.56 (0.37 - 6.70) | |
Missing | 2 | 33 | --- | --- | |
Total | 29 | 20 | p-trend:.1.00 | p-trend:0.75 | |
ERα neg ≤10%# | |||||
<4.0 | 9 | 30 | 1.00 | 1.00 | |
≥4.0 - <8.0 | 12 | 32 | 1.05 (0.44 - 2.50) | 1.16 (0.48 - 2.83) | |
≥8.0 - <13.0 | 13 | 36 | 1.18 (0.50 - 2.75) | 1.38 (0.55 - 3.47) | |
≥13.0 | 15 | 43 | 1.40 (0.61 - 3.19) | 1.61 (0.60 - 4.35) | |
Missing | 1 | 17 | --- | --- | |
Total | 50 | 35 | p-trend:0.38 | p-trend:0.30 | |
ERα pos >10% | |||||
<4.0 | 61 | 206 | 1.00 | 1.00 | |
≥4.0 - <8.0 | 85 | 227 | 1.10 (0.79 - 1.53) | 1.06 (0.75 - 1.48) | |
≥8.0 - <13.0 | 88 | 245 | 1.19 (0.86 - 1.64) | 1.13 (0.79 - 1.60) | |
≥13.0 | 80 | 227 | 1.10 (0.79 - 1.54) | 1.09 (0.75 - 1.61) | |
Missing | 20 | 332 | --- | --- | |
Total | 334 | 232 | p-trend:0.52 | p-trend:0.47 | |
ERβ neg ≤10%# | |||||
<4.0 | 29 | 98 | 1.00 | 1.00 | |
≥4.0 - <8.0 | 38 | 101 | 1.04 (0.64 - 1.68) | 1.04 (0.63 - 1.70) | |
≥8.0 - <13.0 | 44 | 123 | 1.26 (0.79 - 2.01) | 1.26 (0.76 - 2.09) | |
≥13.0 | 40 | 114 | 1.16 (0.72 - 1.87) | 1.20 (0.69 - 2.09) | |
Missing | 9 | 150 | --- | --- | |
Total | 160 | 111 | p-trend:0.40 | p-trend:0.32 | |
ERβ pos >10% | |||||
<4.0 | 33 | 111 | 1.00 | 1.00 | |
≥4.0 - <8.0 | 41 | 109 | 0.98 (0.62 - 1.54) | 0.95 (0.59 - 1.53) | |
≥8.0 - <13.0 | 40 | 111 | 0.98 (0.62 - 1.55) | 0.93 (0.57 - 1.53) | |
≥13.0 | 33 | 94 | 0.84 (0.52 - 1.35) | 0.80 (0.46 - 1.40) | |
Missing | 9 | 150 | --- | --- | |
Total | 156 | 108 | p-trend:0.48 | p-trend:0.62 | |
PgR neg ≤10%# | |||||
<4.0 | 42 | 142 | 1.00 | 1.00 | |
≥4.0 - <8.0 | 49 | 131 | 0.92 (0.61 - 1.39) | 0.91 (0.59 - 1.38) | |
≥8.0 - <13.0 | 50 | 139 | 0.98 (0.65 - 1.48) | 0.96 (0.62 - 1.49) | |
≥13.0 | 49 | 139 | 0.98 (0.65 - 1.48) | 1.01 (0.63 - 1.63) | |
Missing | 9 | 150 | --- | --- | |
Total | 199 | 138 | p-trend:0.98 | p-trend:0.90 | |
PgR pos >10% | |||||
<4.0 | 28 | 94 | 1.00 | 1.00 | |
≥4.0 - <8.0 | 40 | 107 | 1.12 (0.69 - 1.82) | 1.13 (0.69 - 1.86) | |
≥8.0 - <13.0 | 43 | 120 | 1.25 (0.78 - 2.02) | 1.30 (0.78 - 2.16) | |
≥13.0 | 38 | 108 | 1.14 (0.70 - 1.85) | 1.24 (0.70 - 2.17) | |
Missing | 10 | 166 | --- | --- | |
Total | 159 | 110 | p-trend:0.55 | p-trend:0.29 |