Table 2.
Description of mode of detection, tumor characteristics, treatment, and prognosis variables based on percentage density
| All cases (n = 1,774) | PD <25% (n = 1,329) | PD ≥25% (n = 445) | P value | |
|---|---|---|---|---|
| Mode of detection | 0.011 | |||
| Screening-detected | 1,115 (64%) | 867 (67%) | 248 (57%) | |
| Referral for check-up, no symptoms | 25 (1%) | 18 (1%) | 7 (2%) | |
| Referral due to HRT use, no symptoms | 21 (1%) | 15 (1%) | 6 (1%) | |
| Symptomatic | 551 (32%) | 384 (30%) | 167 (39%) | |
| Referral, other reason | 18 (1%) | 13 (1%) | 5 (1%) | |
| Tumor size, mm | 16.8 | 16.4 | 18.0 | 0.007 |
| Lymph node metastasis | 0.581 | |||
| Positive | 480 (28%) | 362 (29%) | 118 (27%) | |
| Negative | 1,221 (72%) | 905 (71%) | 316 (73%) | |
| Histopathologic classification | 0.230 | |||
| Ductal | 1,268 (73%) | 957 (73%) | 311 (72%) | |
| Lobular | 199 (11%) | 140 (11%) | 59 (14%) | |
| Other | 268 (15%) | 206 (16%) | 62 (14%) | |
| ER status | 0.733 | |||
| ER-positive | 971 (79%) | 727 (79%) | 244 (78%) | |
| ER-negative | 256 (21%) | 189 (21%) | 67 (22%) | |
| PR status | 0.779 | |||
| PR-positive | 808 (67%) | 602 (67%) | 206 (68%) | |
| PR-negative | 396 (33%) | 298 (33%) | 98 (32%) | |
| Grade | 0.382 | |||
| 1 | 197 (17%) | 151 (17%) | 46 (15%) | |
| 2 | 510 (43%) | 382 (44%) | 128 (42%) | |
| 3 | 475 (41%) | 342 (39%) | 133 (43%) | |
| Chemo- and endocrine therapy | 0.507 | |||
| Chemotherapy only | 51 (3%) | 34 (3%) | 17 (4%) | |
| Endocrine therapy only | 788 (46%) | 590 (45%) | 198 (46%) | |
| Both | 81 (5%) | 59 (5%) | 22 (5%) | |
| None | 812 (47%) | 615 (47%) | 197 (45%) | |
| Locoregional radiotherapy | 0.425 | |||
| Yes | 1,098 (63%) | 816 (63%) | 282 (65%) | |
| No | 633 (37%) | 481 (37%) | 152 (35%) | |
| Type of breast operation | 0.580 | |||
| Breast-conserving surgery | 1,046 (61%) | 786 (61%) | 260 (60%) | |
| Mastectomy | 683 (40%) | 509 (39%) | 174 (40%) | |
| No surgery | 3 (0%) | 3 (0%) | 0 (0%) | |
| Local recurrence | 0.304 | |||
| Yes | 62 (4%) | 43 (3%) | 19 (4%) | |
| No | 1,668 (96%) | 1,253 (97%) | 415 (96%) | |
| Locoregional recurrence | 0.056 | |||
| Yes | 103 (6%) | 69 (5%) | 34 (8%) | |
| No | 1,627 (94%) | 1,227 (95%) | 400 (92%) | |
| Distant metastasis | 0.361 | |||
| Yes | 187 (11%) | 135 (10%) | 52 (12%) | |
| No | 1,544 (89%) | 1,162 (90%) | 382 (88%) | |
| Breast cancer death within 5 years | 0.405 | |||
| Yes | 124 (7%) | 89 (7%) | 35 (8%) | |
| No | 1,649 (93%) | 1,239 (93%) | 410 (92%) | |
| Breast cancer death within 10 years | 0.204 | |||
| Yes | 213 (12%) | 152 (11%) | 61 (14%) | |
| No | 1,560 (88%) | 1,176 (89%) | 384 (86%) | |
| Death within 5 years independent of cause | 0.902 | |||
| Yes | 174 (10%) | 131 (10%) | 43 (10%) | |
| No | 1,599 (90%) | 1,197 (90%) | 402 (90%) | |
| Death within 10 years independent of cause | 0.599 | |||
| Yes | 358 (20%) | 272 (20%) | 86 (19%) | |
| No | 1,415 (80%) | 1,056 (80%) | 359 (81%) | |
Values are presented as number (percentage) or mean. ER, estrogen receptor; HRT, hormone replacement therapy; PD, percentage density; PR, progesterone receptor.