From: Mammographic density and risk of breast cancer by age and tumor characteristics
 | Number of cases | Number of controls | Odds ratio (95% CI)a | P heterogeneity b |
---|---|---|---|---|
Overall breast cancer | Â | Â | Â | Â |
   0 to 10% | 430 | 1,485 | 0.65 (0.56, 0.74) |  |
   11 to 25% (reference) | 872 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 1,379 | 2,386 | 1.65 (1.48, 1.84) |  |
   51%+ | 733 | 1,080 | 2.15 (1.88, 2.46) |  |
Invasiveness | Â | Â | Â | Â |
Invasive | Â | Â | Â | 0.46 |
   0 to 10% | 372 | 1,485 | 0.66 (0.57, 0.76) |  |
   11 to 25% (reference) | 730 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 1,129 | 2,386 | 1.65 (1.47, 1.86) |  |
   51%+ | 605 | 1,080 | 2.21 (1.92, 2.55) |  |
In situ | Â | Â | Â | Â |
   0 to 10% | 52 | 1,485 | 0.54 (0.38, 0.75) |  |
   11 to 25% (reference) | 139 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 240 | 2,386 | 1.60 (1.28, 2.00) |  |
   51%+ | 124 | 1,080 | 1.87 (1.42, 2.48) |  |
Histology c | Â | Â | Â | 0.04 |
Ductal | Â | Â | Â | Â |
   0 to 10% | 281 | 1,485 | 0.66 (0.56, 0.78) |  |
   11 to 25% (reference) | 556 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 884 | 2,386 | 1.66 (1.46, 1.88) |  |
   51%+ | 466 | 1,080 | 2.14 (1.83, 2.51) |  |
Lobular | Â | Â | Â | Â |
   0 to 10% | 44 | 1,485 | 0.54 (0.37, 0.78) |  |
   11 to 25% (reference) | 100 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 119 | 2,386 | 1.36 (1.03, 1.80) |  |
   51%+ | 84 | 1,080 | 2.69 (1.93, 3.74) |  |
Histologic grade | Â | Â | Â | 0.89 |
Well differentiated | Â | Â | Â | Â |
   0 to 10% | 107 | 1,485 | 0.61 (0.47, 0.77) |  |
   11 to 25% (reference) | 228 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 295 | 2,386 | 1.41 (1.17, 1.70) |  |
   51%+ | 169 | 1,080 | 2.12 (1.68, 2.67) |  |
Moderately differentiated | Â | Â | Â | Â |
   0 to 10% | 146 | 1,485 | 0.69 (0.56, 0.86) |  |
   11 to 25% (reference) | 270 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 430 | 2,386 | 1.70 (1.44, 2.02) |  |
   51%+ | 232 | 1,080 | 2.31 (1.87, 2.84) |  |
Poorly differentiated | Â | Â | Â | Â |
   0 to 10% | 75 | 1,485 | 0.65 (0.48, 0.87) |  |
   11 to 25% (reference) | 148 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 273 | 2,386 | 1.90 (1.53, 2.35) |  |
   51%+ | 143 | 1,080 | 2.34 (1.80, 3.04) |  |
Tumor size | Â | Â | Â | <0.001 |
<1.1Â cm | Â | Â | Â | Â |
   0 to 10% | 179 | 1,485 | 0.93 (0.76, 1.14) |  |
   11 to 25% (reference) | 265 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 353 | 2,386 | 1.37 (1.15, 1.63) |  |
   51%+ | 172 | 1,080 | 1.61 (1.29, 2.01) |  |
1.1 to 2.0Â cm | Â | Â | Â | Â |
   0 to 10% | 121 | 1,485 | 0.54 (0.43, 0.67) |  |
   11 to 25% (reference) | 294 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 453 | 2,386 | 1.64 (1.39, 1.93) |  |
   51%+ | 253 | 1,080 | 2.27 (1.86, 2.77) |  |
2.1+ cm | Â | Â | Â | Â |
   0 to 10% | 56 | 1,485 | 0.42 (0.30, 0.57) |  |
   11 to 25% (reference) | 154 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 280 | 2,386 | 2.07 (1.67, 2.57) |  |
   51%+ | 159 | 1,080 | 3.12 (2.41, 4.04) |  |
Involvement of lymph nodes | Â | Â | Â | 0.01 |
Negative | Â | Â | Â | Â |
   0 to 10% | 257 | 1,485 | 0.67 (0.57, 0.79) |  |
   11 to 25% (reference) | 508 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 744 | 2,386 | 1.54 (1.35, 1.76) |  |
   51%+ | 406 | 1,080 | 2.07 (1.76, 2.44) |  |
Positive | Â | Â | Â | Â |
   0 to 10% | 65 | 1,485 | 0.52 (0.38, 0.70) |  |
   11 to 25% (reference) | 157 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 298 | 2,386 | 1.99 (1.61, 2.45) |  |
   51%+ | 164 | 1,080 | 2.67 (2.07, 3.44) |  |
Estrogen receptor status | Â | Â | Â | 0.66 |
Negative | Â | Â | Â | Â |
   0 to 10% | 48 | 1,485 | 0.61 (0.43, 0.88) |  |
   11 to 25% (reference) | 106 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 192 | 2,386 | 1.79 (1.39, 2.30) |  |
   51%+ | 102 | 1,080 | 2.18 (1.61, 2.96) |  |
Positive | Â | Â | Â | Â |
   0 to 10% | 305 | 1,485 | 0.65 (0.56, 0.77) |  |
   11 to 25% (reference) | 596 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 880 | 2,386 | 1.60 (1.41, 1.82) |  |
   51%+ | 479 | 1,080 | 2.22 (1.9, 2.60) |  |
Progesterone receptor status | Â | Â | 0.10 | |
Negative | Â | Â | Â | Â |
   0 to 10% | 90 | 1,485 | 0.65 (0.50, 0.85) |  |
   11 to 25% (reference) | 187 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 288 | 2,386 | 1.59 (1.30, 1.94) |  |
   51%+ | 151 | 1,080 | 1.99 (1.56, 2.55) |  |
Positive | Â | Â | Â | Â |
   0 to 10% | 265 | 1,485 | 0.66 (0.56, 0.78) |  |
   11 to 25% (reference) | 512 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 782 | 2,386 | 1.65 (1.45, 1.89) |  |
   51%+ | 424 | 1,080 | 2.28 (1.93, 2.68) |  |
HER2 status | Â | Â | Â | 0.69 |
Negative | Â | Â | Â | Â |
   0 to 10% | 189 | 1,485 | 0.66 (0.54, 0.80) |  |
   11 to 25% (reference) | 367 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 560 | 2,386 | 1.63 (1.40, 1.90) |  |
   51%+ | 298 | 1,080 | 2.06 (1.70, 2.49) |  |
Positive | Â | Â | Â | Â |
   0 to 10% | 31 | 1,485 | 0.62 (0.40, 0.97) |  |
   11 to 25% (reference) | 62 | 2,248 | 1.00 (reference) |  |
   26 to 50% | 116 | 2,386 | 1.94 (1.40, 2.69) |  |
   51%+ | 60 | 1,080 | 2.33 (1.57, 3.45) |  |