Table 3.
Patient, tumor and treatment characteristic
| Characteristic | Group | N (%) |
|---|---|---|
| Age group (years) | < 40 | 0 |
| 40-49 | 7 (4.5) | |
| ≥ 50 | 150 (95.5) | |
| Menopausal status | Pre-menopausal | 7 (4.5) |
| Post-menopausal | 141 (89.7) | |
| Peri-menopausal | 9 (5.7) | |
| pT size | ≤ 2 cm | 76 (48.4) |
| > 2 cm | 81 (51.6) | |
| pN stage | Negative (pN0) | 154 (98.2) |
| Positive 1-3 (pN1a) | 3 (1.8) | |
| Final margin | Negative (≥ 2 mm) | 155 (98.7) |
| Close < 2 mm | 2 (1.3) | |
| Tumor grade | I | 7 (4.5) |
| II | 51 (32.5) | |
| III | 99 (63.0) | |
| EIC | Positive | 1 (0.6) |
| Negative | 156 (99.4) | |
| LVI | Positive | 21 (13.4) |
| Negative | 136 (86.6) | |
| ER (estrogen receptor) | Positive | 111 (70.7) |
| Negative | 46 (29.3) | |
| PR (progesterone receptor) | Positive | 96 (61.1) |
| Negative | 61 (38.9) | |
| Her2neu status | Negative | 129 (82.2) |
| Positive | 28 (17.8) | |
| Molecular subtype | Luminal A | 54 (34.4) |
| Luminal B | 57 (36.3) | |
| Her2neu | 17 (10.8) | |
| TNBC | 29 (18.5) | |
| Updated ASTRO consensus groups | Suitable | 46 (29.3) |
| Cautionary | 106 (67.5) | |
| Unsuitable | 5 (3.2) | |
| GEC-ESTRO risk groups | Low-risk | 123 (78.3) |
| Intermediate-risk | 10 (6.4) | |
| High-risk | 24 (15.3) | |
| Chemotherapy | Yes | 85 (54.0) |
| No | 72 (46.0) | |
| Endocrine therapy | Yes | 111 (70.7) |
| No | 46 (29.3) | |
| Timing of implant | Intra-operative | 87 (55.0) |
| Post-operative | 40 (45.0) |
EIC – extensive intraductal component, LVI – lymphovascular invasion, Her2neu – human epidermal growth factor receptor 2, ASTRO – American Society for Therapeutic Radiology and Oncology, GEC-ESTRO – the Groupe Européen de Curiethérapie and the European Society for Radiotherapy & Oncology