Table 1.
Clinical characteristics and treatment of different breast cancer subtypes
| Variables | All cases | Luminal A | Luminal B (high KI-67) | Luminal B (Her2/neu+) | Her2/neu | TN | P-value |
|---|---|---|---|---|---|---|---|
| No. (%) | 5809 | 1805 (31.1%) | 1765 (30.4%) | 760 (13.1%) | 522 (9.0%) | 957 (16.5%) | |
| Age | |||||||
| Mean ± SD (years) | 47.5 ± 10.7 | 51.0 ± 11.2 | 43.0 ± 9.7 | 47.5 ± 9.6 | 47.9 ± 9.9 | 47.4 ± 10.6 | <0.0001 |
| Age-specific groups, n (%) | |||||||
| 35 | 752 (12.9) | 152 (8.4) | 321 (18.2) | 80 (10.5) | 72 (13.8) | 127 (13.3) | <0.0001 |
| 36–69 | 4859 (83.6) | 1534 (85.0) | 1412 (80.0) | 671 (88.3) | 455 (85.2) | 797 (83.3) | |
| 70 | 198 (3.4) | 119 (6.6) | 32 (1.8) | 9 (1.2) | 5 (1.0) | 33 (3.4) | |
| Menopausal status n (%) | |||||||
| Premenopausal | 3347 (57.6) | 723 (40.1) | 1289 (73.0) | 389 (51.2) | 313 (60.0) | 633 (66.1) | <0.0001 |
| Postmenopausal | 2462 (42.4) | 1082 (59.9) | 476 (27.0) | 371 (48.8) | 209 (40.0) | 324 (33.9) | |
| Tumor size, n (%) | |||||||
| 2.0 cm | 1744 (30.0) | 608 (33.7) | 555 (31.4) | 205 (27.0) | 121 (23.2) | 255 (26.6) | <0.0001 |
| 2.0–5.0 cm | 3630 (62.5) | 1090 (60.4) | 1109 (62.8) | 475 (62.5) | 331 (63.4) | 625 (65.3) | |
| >5.0 cm | 435 (7.5) | 107 (5.9) | 101 (5.7) | 80 (10.5) | 70 (13.4) | 77 (8.0) | |
| Lymph node status, n (%) | |||||||
| 0 | 2876 (49.5) | 1039 (57.6) | 849 (48.1) | 265 (34.9) | 210 (40.2) | 513 (53.6) | <0.0001 |
| 1–3 | 1568 (27.0) | 475 (26.3) | 459 (26.0) | 251 (33.0) | 139 (26.6) | 244 (25.5) | |
| 4–9 | 799 (13.8) | 176 (9.8) | 273 (15.5) | 135 (17.8) | 90 (17.2) | 125 (13.1) | |
| >10 | 566 (9.7) | 115 (6.4) | 184 (10.4) | 109 (14.3) | 83 (15.9) | 75 (7.8) | |
| AJCC stage group, n (%) | |||||||
| Stage I | 1080 (18.6) | 771 (21.6) | 342 (19.4) | 86 (11.3) | 59 (11.3) | 164 (17.1) | <0.0001 |
| Stage II | 3248 (55.9) | 1989 (55.7) | 937 (53.1) | 408 (53.7) | 277 (53.1) | 574 (60.0) | |
| Stage III | 1481 (25.5) | 810 (22.7) | 486 (27.5) | 266 (35.0) | 186 (35.6) | 219 (22.9) | |
| Hormonal receptor status | |||||||
| ER+ | 3601 (62.0) | 1587 (87.9) | 1496 (84.8) | 518 (68.2) | 0 (0.0) | 0 (0.0) | <0.0001 |
| PR+ | 3897 (67.1) | 1644 (91.1) | 1602 (90.8) | 651 (85.7) | 0 (0.0) | 0 (0.0) | |
| ER+/PR+ | 4330 (74.5) | 1805 (100.0) | 1765 (100.0) | 760 (100.0) | 0 (0.0) | 0 (0.0) | |
| HER2 status | |||||||
| Positive | 1282 (22.1) | 0 (0.0) | 0 (0.0) | 760 (100.0) | 522 (0.0) | 0 (0.0) | <0.0001 |
| Negative | 4527 (77.9) | 3570 (100.0) | 1765 (100.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| Histologic grade, n (%) | |||||||
| I | 1455 (24.9) | 792 (43.9) | 482 (27.3) | 59 (7.8) | 38 (7.3) | 74 (7.7) | <0.0001 |
| II | 1869 (32.2) | 690 (38.2) | 624 (35.4) | 293 (38.6) | 138 (26.4) | 124 (13.0) | |
| III | 2495 (43.0) | 323 (17.9) | 659 (37.5) | 408 (53.7) | 346 (66.3) | 759 (79.3) | |
| Ki-67, n (%) | |||||||
| 15% | 1901 (32.7) | 1625 (90.0) | 0 (0.0) | 91 (12.0) | 45 (8.6) | 140 (14.6) | |
| >15% | 3610 (62.1) | 0 (0.0) | 1765 (100.0) | 629 (82.8) | 443 (84.9) | 773 (80.8) | |
| Unknown | 298 (5.1) | 180 (5.0) | 0 (0.0) | 40 (5.3) | 34 (6.5) | 44 (4.6) | <0.0001 |
| LVI, n (%) | |||||||
| Yes | 157 (2.7) | 38 (2.1) | 44 (2.5) | 27 (3.6) | 25 (4.8) | 23 (2.4) | 0.164 |
| No | 5652 (97.3) | 1767 (97.9) | 1721 (97.5) | 733 (96.4) | 497 (95.2) | 934 (97.6) | |
| Primary surgery | |||||||
| Mastectomy | 5541 (95.4) | 1728 (95.7) | 1677 (95.0) | 726 (95.5) | 498 (95.4) | 912 (95.3) | 0.001 |
| BCS | 268 (4.6) | 77 (4.3) | 88 (5.0) | 34 (4.5) | 24 (4.6) | 45 (4.7) | |
| Adjuvant chemotherapy | |||||||
| Yes | 5130 (88.3) | 1459 (80.8) | 1588 (90.0) | 722 (95.0) | 490 (93.9) | 871 (91.0) | 0.001 |
| No | 679 (11.7) | 346 (19.2) | 177 (10.0) | 38 (5.0) | 32 (6.1) | 86 (9.0) | |
| Adjuvant chemotherapy type | |||||||
| CMF regimens | 670 (11.5) | 273 (15.1) | 181 (10.3) | 58 (7.8) | 29 (5.6) | 128 (13.4) | <0.0001 |
| Anthracycline-based | 2896 (49.9) | 789 (43.7) | 932 (52.8) | 373 (49.1) | 289 (55.4) | 513 (53.6) | |
| Taxen-based | 1564 (26.9) | 397 (22.0) | 475 (26.9) | 290 (38.2) | 172 (33.0) | 230 (24.0) | |
| No | 679 (11.7) | 346 (19.2) | 177 (10.0) | 38 (5.0) | 32 (6.1) | 86 (9.0) | |
| Adjuvant radiotherapy | |||||||
| Yes | 1354 (23.3) | 343 (19.0) | 457 (25.9) | 211 (27.8) | 136 (26.1) | 207 (21.6) | <0.0001 |
| No | 4455 (76.7) | 1642 (81.0) | 1308 (74.1) | 549 (72.2) | 386 (73.9) | 750 (78.4) | |
| Adjuvant endocrine therapy | |||||||
| ER antagonist | 3671 (63.2) | 1474 (81.7) | 1479 (83.8) | 632 (83.2) | 29 (5.6) | 102 (10.7) | <0.0001 |
| Aromatase inhibitor | 374 (6.4) | 130 (7.2) | 122 (6.9) | 57 (7.5) | 4 (0.8) | 16 (1.7) | |
| No | 1764 (30.4) | 201 (11.1) | 164 (9.3) | 71 (9.3) | 489 (93.7) | 839 (87.7) | |
AJCC, American Joint Committee on Cancer; BCS, breast-conserving surgery; CMF, cyclophosphamide, methotrexate, and 5-fluorouracil (5FU); ER, estrogen receptor; PR, progesterone receptor; SD, standard deviation; TN, triple negative subtype.