Table 1.
Baseline characteristics of all 2295 ER+ breast cancer patients by AI–endocrine treatment ratio at the end of follow-upa
| Characteristic | AI < 25% | AI 25%-75% | AI > 75% |
|---|---|---|---|
| Total, No. (%) | 624 (100) | 1091 (100) | 580 (100) |
| Mean age (range), y | 47.4 (45-50) | 47.8 (45-50) | 47.9 (45-50) |
| pT-stage, No. (%) | |||
| 1 | 232 (37.1) | 451 (41.3) | 226 (39.0) |
| 2 | 333 (53.4) | 548 (50.3) | 297 (51.2) |
| 3 | 39 (6.3) | 64 (5.9) | 29 (5.0) |
| 4 | 8 (1.3) | 8 (0.7) | 4 (0.7) |
| Unknown | 12 (1.9) | 20 (1.8) | 24 (4.1) |
| Grade, No. (%) | |||
| I | 69 (11.1) | 150 (13.8) | 65 (11.2) |
| II | 282 (45.2) | 514 (47.1) | 243 (41.9) |
| III | 211 (33.8) | 334 (30.6) | 217 (37.4) |
| Unknown | 62 (9.9) | 93 (8.5) | 55 (9.5) |
| Positive lymph nodes, No. (%) | |||
| 0 | 151 (24.2) | 312 (28.6) | 174 (30.0) |
| 1-3 | 324 (51.9) | 566 (51.9) | 251 (43.2) |
| 4-9 | 93 (14.9) | 153 (14.0) | 113 (19.5) |
| >10 | 53 (8.5) | 56 (5.1) | 38 (6.6) |
| Unknown | 3 (0.5) | 4 (0.4) | 4 (0.7) |
| PR status, No. (%) | |||
| Negative | 80 (12.8) | 97 (8.9) | 100 (17.2) |
| Positive | 519 (83.2) | 938 (86.0) | 451 (77.8) |
| Unknown | 25 (4.0) | 56 (5.1) | 29 (5.0) |
| HER2 status, No. (%) | |||
| Negative | 528 (84.6) | 951 (87.1) | 314 (54.1) |
| Positive | 39 (6.3) | 39 (3.6) | 194 (33.5) |
| Unknown | 57 (9.1) | 101 (9.3) | 72 (12.4) |
|
Trastuzumab, No. (%) |
|||
| No | 603 (96.6) | 1068 (97.9) | 452 (77.9) |
| Yes | 21(3.4) | 23 (2.1) | 128 (22.1) |
| Ovarian ablation, No. (%) | |||
| Yesb | 155 (24.8) | 221 (20.3) | 122 (21.0) |
| Surgery | 54 | 129 | 69 |
| GnRH | 121 | 128 | 80 |
| No | 469 (75.2) | 870 (79.7) | 458 (79.0) |
| Chemotherapyc, No. (%) | |||
| Yes | 624 (100) | 1091 (100) | 580 (100) |
| Anthracycline based | 481 (77.1) | 861 (78.9) | 367 (63.3) |
| Anthracycline and taxane based | 118 (18.9) | 207 (19.0) | 184 (31.7) |
| Other | 25 (4.0) | 23 (2.1) | 29 (5.0) |
| No | 0 (0) | 0 (0) | 0 (0) |
The AI–endocrine treatment ratio is defined as the percentage of total endocrine treatment duration (AI+tamoxifen) that was spent on AI treatment. AI = aromatase inhibitor; ER+ = estrogen receptor positive; GnRH = gonadotropin-releasing hormone agonist; PR = progesterone receptor; pT-stage = pathologic T-stage.
Numbers may not add up because some patients received a GnRH before their surgery.
Anthracycline-based schedules: doxorubicin + cyclofosfamide (AC), 5-FU + epirubicin + cyclofosfamide (FEC/CEF), 5-FU + doxorubicin + cyclofosfamide (FAC/CAF). Anthracycline- and taxane-based schedules: docetaxel + doxorubicin + cyclofosfamide (TAC), doxorubicin + docetaxel (DA).