Table 1. Baseline characteristics of the 412 patients in the primary analysis group.
| n | % | |
|---|---|---|
| Patients who had mammography | 364 | 88.3 |
| Patients who had fine-needle aspiration | 365 | 88.6 |
| Patients who had a core biopsy | 55 | 13.3 |
| Age at first surgery (years) – median (Q1, Q3) | 43 | (40, 46) |
| (min., max.) | (22, 54) | |
| LMP group at first surgery | ||
| 0–4 days | 64 | 15.5 |
| 5–9 days | 70 | 17.0 |
| 10–14 days | 61 | 14.8 |
| 15–19 days | 62 | 15.0 |
| 20–24 days | 71 | 17.2 |
| 25–29 days | 39 | 9.5 |
| 30+ days | 31 | 7.5 |
| Unidentifiablea | 14 | 3.4 |
| Type of first surgery | ||
| Excision biopsy | 74 | 18.0 |
| Lumpectomy | 197 | 47.8 |
| Mastectomy | 138 | 33.5 |
| Axillary procedure only | 1 | 0.2 |
| Neoadjuvant therapy | 1 | 0.2 |
| Missing | 1 | 0.2 |
| Type of axillary procedure at first surgery | ||
| None | 100 | 24.3 |
| Sample | 69 | 16.7 |
| Clearance | 243 | 59.0 |
| Further surgery required | 134 | 32.5 |
| Adjuvant treatment received | 402 | 97.6 |
| Chemotherapy given | 278 | 69.2 |
| Hormone therapy given | 278 | 69.2 |
| Radiotherapy given | 320 | 79.6 |
| Histological grade | ||
| I | 59 | 14.3 |
| II | 181 | 43.9 |
| III | 154 | 37.4 |
| Missing | 18 | 4.4 |
| Tumour size (mm) – median (Q1, Q3) | 20 | (15, 30) |
| (min., max.) | (0.5, 150) | |
| Number of nodes sampled – median (Q1, Q3) | 11 | (7, 16) |
| (min., max.) | (0, 36) | |
| Nodal status | ||
| Positive | 208 | 50.5 |
| Negative | 193 | 46.8 |
| Missing | 11 | 2.7 |
| NPI prognostic groups – three categories | ||
| Good | 110 | 26.7 |
| Moderate | 176 | 42.7 |
| Poor | 95 | 23.1 |
| Missing | 31 | 7.5 |
LMP=last menstrual period; NPI=Nottingham Prognostic Index.
a
Patients whose LMP date or surgery date is missing, or who had neoadjuvant therapy, are classed as having an unidentifiable LMP group.