Table 1. Clinical and pathologic characteristics according to the screen-adherence.
| Original Cohort | Case-matched cohort | |||||
|---|---|---|---|---|---|---|
| Variables | Screening-adherence (n = 450) | Screening-non-adherence (n = 182) | P-value | Screening-adherence (n = 137) | Screening-non-adherence (n = 137) | P-value |
| Age, median (range) | 51 (40–87) | 49 (40–82) | 0.055 | 50 (40–84) | 49 (40–82) | 0.462 |
| Tumor size, median (range) | 1.2 (0.1–2.0) | 1.5 (0.3–2.0) | <0.001 | 1.5 (0.3–2.0) | 1.5 (0.3–2.0) | 0.872 |
| Mammographic density a, b | 0.094 | 0.348 | ||||
| I | 11 (2.7) | 2 (1.2) | 4 (3.1) | 1 (0.8) | ||
| II | 51 (12.4) | 32 (18.6) | 16 (12.5) | 22 (17.1) | ||
| III | 286 (69.8) | 120 (69.8) | 91 (71.1) | 93 (72.1) | ||
| IV | 62 (15.1) | 18 (10.5) | 17 (13.3) | 13 (10.1) | ||
| T stage | <0.001 | 0.878 | ||||
| T1a | 47 (10.4) | 6 (3.3) | 6 (4.4) | 6 (4.4) | ||
| T1b | 115 (25.6) | 24 (13.2) | 19 (13.9) | 22 (16.1) | ||
| T1c | 288 (64.0) | 152 (83.5) | 112 (81.8) | 109 (79.6) | ||
| N stage | 0.004 | 0.802 | ||||
| 0 | 356 (79.1) | 133 (73.1) | 103 (75.2) | 106 (77.4) | ||
| N1 | 89 (19.8) | 38 (20.9) | 32 (23.4) | 30 (21.9) | ||
| N2 | 4 (0.9) | 8 (4.4) | 2 (1.5) | 1 (0.7) | ||
| N3 | 1 (0.2) | 3 (1.6) | ||||
| Stage | <0.001 | 0.988 | ||||
| I | 366 (81.3) | 136 (74.7) | 109(79.6) | 108 (78.8) | ||
| II | 80 (17.8) | 35 (19.2) | 26 (19.0) | 27 (19.7) | ||
| III | 4 (0.9) | 11 (6.0) | 2 (1.5) | 2 (1.5) | ||
| Grade a | <0.001 | 0.881 | ||||
| I or II | 373 (86.9) | 126 (72.0) | 110 (80.3) | 108 (78.8) | ||
| III | 56 (13.1) | 49 (28.0) | 27 (19.7) | 29 (21.2) | ||
| Estrogen receptor c | 0.040 | 0.398 | ||||
| Positive | 334 (74.2) | 120 (65.9) | 95 (69.3) | 92 (67.2) | ||
| Negative | 116 (25.8) | 62 (34.1) | 42 (30.7) | 45 (32.8) | ||
| Progesterone receptor c | 0.471 | 0.623 | ||||
| Positive | 280 (62.2) | 107 (58.8) | 84 (61.3) | 79 (57.7) | ||
| Negative | 170 (37.8) | 75 (41.2) | 53 (42.3) | 58 (42.3) | ||
| HER2 | 0.026 | 0.352 | ||||
| Negative | 351 (81.2) | 122 (72.6) | 115 (83.9) | 108 (78.8) | ||
| Positive | 81 (18.8) | 46 (27.4) | 22 (16.1) | 29 (21.2) | ||
| Ki67 a | 0.194 | 1.000 | ||||
| ≥20 | 87 (19.4) | 44 (24.2) | 32 (23.4) | 32 (23.4) | ||
| <20 | 362 (80.6) | 138 (75.8) | 105 (76.6) | 105 (76.6) | ||
| Surgery | <0.001 | 0.182 | ||||
| BCS | 287 (63.8) | 87 (47.8) | 81 (59.1) | 69 (50.4) | ||
| TM | 163 (36.2) | 95 (52.2) | 56 (40.9) | 68 (49.6) | ||
| Chemotherapy | <0.001 | 0.146 | ||||
| Not given | 248 (55.1) | 70 (38.7) | 70 (51.1) | 57 (41.6) | ||
| Given | 202 (44.9) | 111 (61.3) | 67 (48.9) | 80 (58.4) | ||
| Endocrine therapy | 0.007 | 0.256 | ||||
| Not given | 83 (18.4) | 52 (28.6) | 28 (20.4) | 37 (27.0) | ||
| Given | 367 (81.6) | 130 (71.4) | 109 (79.6) | 100 (73.0) | ||
| Radiotherapy | 0.040 | 0.394 | ||||
| Not given | 170 (37.8) | 85 (46.7) | 56 (40.9) | 64 (46.7) | ||
| Given | 280 (62.2) | 97 (53.3) | 81 (59.1) | 73 (53.3) | ||
a Missing value
b Mammographic density was categorized according to Breast Imaging Reporting and Data System
c Positive, Allred score 2–8; Negative, Allred score 0–1.
Abbreviations: HER2, human epidermal growth factor receptor 2; BCS, breast-conserving surgery; TM, total mastectomy