Table 1. Patient characteristics at baseline (N=735).
| Patient characteristics | No. of patients (%) |
|---|---|
| Age | |
| Median (range), year | 45 (26–86) |
| Menopausal status | |
| Premenopausal | 555 (75.5) |
| Postmenopausal | 180 (24.5) |
| Tumor laterality | |
| Left | 371 (50.5) |
| Right | 363 (49.4) |
| Bilateral | 1 (0.1) |
| Modified N stage† | |
| N0 | 290 (39.5) |
| N+ | 445 (60.5) |
| Modified stage‡ | |
| I (IA/IB) | 193 (26.2) |
| II (IIA/IIB) | 332 (45.2) |
| III (IIIA/IIIB/IIIC) | 210 (28.6) |
| Immunohistochemistry subgroup | |
| HR+/HER2− | 436 (59.3) |
| HER2+/HR− | 77 (10.5) |
| HER2+/HR+ | 108 (14.7) |
| HR−/HER2− | 114 (15.5) |
| Surgical approaches | |
| Breast conserving therapy (BCT) | 373 (50.7) |
| Mastectomy | 362 (49.3) |
| Sentinel lymph node biopsy (SLNB) | 265 (36.1) |
| Axillary lymph node dissection (ALND) | 470 (63.9) |
| Chemotherapy strategy | |
| None | 69 (9.4) |
| Neoadjuvant | 131 (17.8) |
| Adjuvant | 513 (69.8) |
| Neoadjuvant + adjuvant | 22 (3.0) |
| Chemotherapy regimens | |
| None | 69 (9.4) |
| Anthracycline | 17 (2.3) |
| Taxane | 183 (24.9) |
| Anthracycline + taxane | 464 (63.1) |
| Others | 2 (0.3) |
| Anti-HER2 therapy | |
| None | 556 (75.6) |
| Yes | 179 (24.4) |
| Endocrine therapy | |
| None | 186 (25.3) |
| Yes | 549 (74.7) |
| Radiotherapy technique | |
| RapidArc | 123 (16.7) |
| 2D-fields | 277 (37.7) |
| 3DCRT | 335 (45.6) |
| RT fields | |
| Tangential breast only | 277 (37.7) |
| Breast/chest wall + SCF | 322 (43.8) |
| Breast/chest wall + SCF + IMN | 123 (16.7) |
| Breast/chest wall + SCF + Axillary | 13 (1.8) |
| RT dose and fractions | |
| 40.5 Gy/15 fx | 665 (90.5) |
| 50 Gy/25 fx | 61 (8.3) |
| 50–60 Gy/25 fx | 9 (1.2) |
| Use of RPM | |
| None | 721 (98.1) |
| Yes | 14 (1.9) |
| Treatment volume (95% CI), cc | 1,690.8 (1,652.2, 1,729.4) |
| Mean heart dose (95% CI), Gy | 2.4 (2.2–2.5) |
| Integral dose of the total body (95% CI), Gy | 4.4 (4.3–4.5) |
| Mean dose of ipsilateral lung (95% CI), Gy | 10.1 (9.8–10.3) |
| Mean dose of bilateral lungs (95% CI), Gy | 5.5 (5.3–5.6) |
† Modified N stage: the higher N stage between clinic N stage and yp N stage for patients who had received neoadjuvant chemotherapy; ‡ modified stage: the higher stage between clinic stage and yp stage for patients who had received neoadjuvant chemotherapy. RT, radiotherapy; N, lymph nodes; BCT, breast-conserving therapy; SLNB, sentinel lymph node biopsy; ALND, axillary lymph node dissection; SCF, supraclavicular lymph nodes; IMN, internal mammary nodal; fx, fraction; RPM, real-time position management.