Table 2 Local control (LC) outcomes according to clinical factors
N (%) | 2-year LC | P-value | ||
|---|---|---|---|---|
Entire | 49.4% | |||
Age | < 45 years | 33 (24.8) | 48.7% | 0.830 |
≥ 45 years | 100 (75.2) | 50.0% | ||
Subtype | HR positive/HER2 negative | 48 (36.1) | 56.0% | 0.210 |
HR positive/HER2 positive | 19 (14.3) | 34.3% | ||
HR negative/HER2 positive | 19 (14.3) | 30.0% | ||
TN | 47 (35.3) | 57.1% | ||
Treatment era | 2010–2015 | 52 (39.1) | 42.6% | 0.087 |
2016–2021 | 81 (60.9) | 55.8% | ||
Previous systemic treatments | ≤ 2 lines | 72 (54.1) | 62.7% | < .001 |
> 2 lines | 61 (45.9) | 27.6% | ||
Interval from diagnosis to PRT | ≤ 1 year | 65 (48.9) | 58.5% | 0.053 |
> 1 year | 68 (51.1) | 38.9% | ||
No vs. Yes | ||||
Disease extent at PRT | LN | 61 (45.9) | 55.7% vs. 42.5% | 0.110 |
Liver | 26 (19.5) | 50.4% vs. 44.1% | 0.260 | |
Lung | 59 (44.4) | 46.2% vs. 54.9% | 0.810 | |
Bone | 72 (54.1) | 52.1% vs. 48.5% | 0.860 | |
Brain | 5 (3.8) | 50.9% vs. 0.0% | < .001 | |
Number of metastases | Oligometastasis (≤ 5 lesions) | 13 (9.8) | 66.7% | 0.330 |
Polymetastasis (> 5 lesions) | 120 (90.2) | 47.6% | ||
Status | De novo stage IV | 30 (22.6) | 64.2% | 0.076 |
Progressive stage IV | 76 (57.1) | 46.1% | ||
Recurrent stage IV | 27 (20.3) | 45.1% | ||
Disease burden (outside breast) | SD | 104 (78.2) | 54.1% | 0.003 |
PD or mixed response | 29 (21.8) | 24.4% | ||
Reason for breast PRT | Symptom (bleeding, pain) | 51 (38.3) | 62.3% | 0.180 |
Radiologic progression | 82 (61.7) | 42.1% | ||
Concurrent treatment | No | 50 (37.6) | 54.3% | 0.360 |
Endocrine therapy | 27 (20.3) | 59.2% | ||
Anti-HER2 therapy | 10 (7.5) | 50.0% | ||
Cytotoxic chemotherapy | 46 (34.6) | 34.8% | ||
Gross tumor volume | < 1260 cm3 | 107 (80.5) | 50.2% | 0.110 |
≥ 1260 cm3 | 26 (19.5) | 46.2% | ||
PRT dose (EQD2) | < 63 Gy | 72 (54.1) | 42.9% | 0.010 |
≥ 63 Gy | 61 (45.9) | 67.7% | ||
PRT modality | 3D-CRT | 74 (55.6) | 44.5% | 0.330 |
IMRT/Proton | 59 (44.4) | 56.5% |