Table 2 Description of mode of detection, tumor characteristics, treatment, and prognosis variables based on percentage density
From: Possible influence of mammographic density on local and locoregional recurrence of breast cancer
|  | All cases (n= 1,774) | PD <25% (n= 1,329) | PD ≥25% (n= 445) | Pvalue |
|---|---|---|---|---|
Mode of detection | Â | Â | Â | 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 | Â | Â | Â | 0.581 |
   Positive | 480 (28%) | 362 (29%) | 118 (27%) |  |
   Negative | 1,221 (72%) | 905 (71%) | 316 (73%) |  |
Histopathologic classification | Â | Â | Â | 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 | Â | Â | Â | 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 | Â | Â | Â | 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 | Â | Â | Â | 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 | Â | Â | Â | 0.425 |
   Yes | 1,098 (63%) | 816 (63%) | 282 (65%) |  |
   No | 633 (37%) | 481 (37%) | 152 (35%) |  |
Type of breast operation | Â | Â | Â | 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 | Â | Â | Â | 0.304 |
   Yes | 62 (4%) | 43 (3%) | 19 (4%) |  |
   No | 1,668 (96%) | 1,253 (97%) | 415 (96%) |  |
Locoregional recurrence | Â | Â | Â | 0.056 |
   Yes | 103 (6%) | 69 (5%) | 34 (8%) |  |
   No | 1,627 (94%) | 1,227 (95%) | 400 (92%) |  |
Distant metastasis | Â | Â | Â | 0.361 |
   Yes | 187 (11%) | 135 (10%) | 52 (12%) |  |
   No | 1,544 (89%) | 1,162 (90%) | 382 (88%) |  |
Breast cancer death within 5 years | Â | Â | Â | 0.405 |
   Yes | 124 (7%) | 89 (7%) | 35 (8%) |  |
   No | 1,649 (93%) | 1,239 (93%) | 410 (92%) |  |
Breast cancer death within 10 years | Â | Â | Â | 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 | Â | Â | Â | 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 | Â | Â | Â | 0.599 |
   Yes | 358 (20%) | 272 (20%) | 86 (19%) |  |
   No | 1,415 (80%) | 1,056 (80%) | 359 (81%) |  |