Table 3. Univariate logistic analysis of lymphopenia post-RT and nadir-PLC/pre-PLC <0.8.
| Clinical characteristic factor | No. of patients (%) | Lymphopenia post-RT | Nadir-PLC/pre-PLC <0.8 | |||
|---|---|---|---|---|---|---|
| Odds ratio (95% CI) | P value | Odds ratio (95% CI) | P value | |||
| Age | 735 (100.0) | 0.99 (0.97, 1.00) | 0.08 | 1.01 (0.99, 1.03) | 0.22 | |
| Menopausal status | 0.16 | 0.07 | ||||
| Premenopausal | 555 (75.5) | 1 | 1 | |||
| Postmenopausal | 180 (24.5) | 0.78 (0.55, 1.10) | 1.49 (0.97, 2.32) | |||
| Tumor laterality | ||||||
| Left breast | 371 (54.5) | 1 | 1 | |||
| Right breast | 363 (49.4) | 1.38 (1.02, 1.85) | 0.04 | 1.25 (0.88, 1.78) | 0.21 | |
| Bilateral breasts | 1 (0.1) | NA‡ | NA‡ | NA‡ | NA‡ | |
| Modified N stage | <0.001 | <0.001 | ||||
| N0 | 290 (39.5) | 1 | 1 | |||
| N+ | 445 (60.5) | 3.21 (2.36, 4.39) | 3.14 (2.20, 4.52) | |||
| Immunohistochemistry subgroup | ||||||
| HR+/HER2− | 436 (59.3) | 1 | 1 | |||
| HER2+/HR− | 77 (10.5) | 1.03 (0.63, 1.71) | 0.91 | 0.87 (0.50, 1.57) | 0.64 | |
| HER2+/HR+ | 108 (14.7) | 0.96 (0.64, 1.48) | 0.84 | 1.26 (0.75, 2.20) | 0.4 | |
| HR−/HER2− | 114 (15.5) | 1.09 (0.71, 1.67) | 0.7 | 0.97 (0.60, 1.61) | 0.9 | |
| Surgical approaches | ||||||
| Breast conserving therapy (BCT) | 373 (50.7) | 1 | 1 | |||
| Mastectomy | 362 (49.3) | 2.30 (1.70, 3.12) | <0.001 | 2.25 (1.57, 3.25) | <0.001 | |
| Sentinel lymph node biopsy (SLNB) | 265 (36.1) | 1 | 1 | |||
| Axillary lymph node dissection (ALND) | 470 (63.9) | 3.32 (2.43, 4.56) | <0.001 | 3.25 (2.27, 4.67) | <0.001 | |
| Pre-RT lymphocyte counts | 735 (100.0) | 0.15 (0.11, 0.22) | <0.001 | – | – | |
| Chemotherapy | <0.001 | 0.9 | ||||
| None | 69 (9.4) | 1 | 1 | |||
| Yes | 666 (90.6) | 3.81 (2.28, 6.58) | 0.96 (0.51, 1.71) | |||
| Chemotherapy regimens | ||||||
| None | 69 (9.4) | 1 | 1 | |||
| Anthracycline | 17 (2.3) | 6.86 (2.12, 26.86) | 0.002 | 0.76 (0.23, 3.05) | 0.68 | |
| Taxane | 183 (24.9) | 1.95 (1.09, 3.56) | 0.26 | 0.54 (0.27, 1.02) | 0.07 | |
| Anthracycline+taxane | 464 (63.1) | 5.37 (3.14, 9.48) | <0.001 | 1.14 (0.58, 2.09) | 0.69 | |
| Others | 2 (0.3) | NA‡ | NA‡ | NA‡ | NA‡ | |
| Chemotherapy strategy | ||||||
| None | 69 (9.4) | 1 | ||||
| Neoadjuvant | 131 (17.8) | 7.35 (3.89, 14.30) | <0.001 | 4.83 (1.93, 13.27) | 0.001 | |
| Adjuvant | 513 (69.8) | 3.29 (1.95, 5.72) | <0.001 | 0.76 (0.40, 1.36) | 0.38 | |
| Neoadjuvant + adjuvant | 22 (3.0) | 3.82 (1.43, 10.85) | 0.01 | 0.93 (0.31, 3.18) | 0.90 | |
| Anti-HER2 therapy | 0.91 | 0.76 | ||||
| None | 556 (75.6) | 1 | 1 | |||
| Yes | 179 (24.4) | 1.02 (0.72, 1.44) | 1.07 (0.71, 1.62) | |||
| Endocrine therapy | 0.7 | 0.43 | ||||
| None | 186 (25.3) | 1 | 1 | |||
| Yes | 549 (74.7) | 0.94 (0.66, 1.32) | 1.17 (0.79, 1.72) | |||
| Radiotherapy technique | ||||||
| RapidArc | 123 (16.7) | 1 | 1 | |||
| 2D-fields | 277 (37.7) | 0.04 (0.02, 0.09) | <0.001 | 0.03 (0.01, 0.09) | <0.001 | |
| 3DCRT | 335 (45.6) | 0.11 (0.05, 0.22) | <0.001 | 0.08 (0.01, 0.26) | <0.001 | |
| RT fields | <0.001 | <0.001 | ||||
| Breast | 277 (37.7) | 1 | 1 | |||
| Breast/chest wall + regional LNs† | 458 (62.3) | 3.64 (2.67, 5.00) | 3.80 (2.65, 5.50) | |||
| RT dose (Gy) | ||||||
| 40.5 | 665 (90.5) | 1 | 1 | |||
| 50 | 61 (8.3) | 2.64 (1.44, 5.16) | 0.003 | 2.00 (0.98, 4.63) | 0.08 | |
| 50–60 | 9 (1.2) | NA‡ | NA‡ | NA‡ | NA‡ | |
| RT fractions | <0.001 | 0.03 | ||||
| 15 fx | 665 (90.5) | 1 | 1 | |||
| 25 fx | 70 (9.5) | 3.13 (1.73, 6.07) | 2.34 (1.16, 5.38) | |||
| Use of RPM | 0.07 | 0.49 | ||||
| None | 721 (98.1) | 1 | 1 | |||
| Yes | 14 (1.9) | 3.99 (1.08, 25.77) | 1.71 (0.46, 11.07) | |||
| Treatment volume, cc | 735 (100.0) | 1.001 (1.001, 1.002) | <0.001 | 1.002 (1.001, 1.002) | <0.001 | |
| Mean heart dose, Gy | 735 (100.0) | 1.24 (1.15, 1.35) | <0.001 | 1.25 (1.13, 1.39) | <0.001 | |
| Integral dose of the total body, Gy | 735 (100.0) | 1.99 (1.73, 2.32) | <0.001 | 2.03 (1.69, 2.48) | <0.001 | |
| Mean dose of bilateral lungs, Gy | 735 (100.0) | 1.51 (1.39, 1.66) | <0.001 | 1.46 (1.32, 1.62) | <0.001 | |
†Regional LNs: include supraclavicular, axillary levels I–III, and internal mammary nodal; NA‡: sample was too small to analyze. RT, radiotherapy; N, lymph nodes; BCT, breast-conserving therapy; SLNB, sentinel lymph node biopsy; ALND, axillary lymph node dissection; fx, fraction; RPM, real-time position management.