Table 1.
Demographic, clinical, and treatment characteristics at randomisation (n=4096)*
| 40 Gy in 15 fractions (n=1361) | 27 Gy in five fractions (n=1367) | 26 Gy in five fractions (n=1368) | ||||
|---|---|---|---|---|---|---|
| Age, years | ||||||
| Median (IQR) | 60 (53–66) | 61 (53–67) | 61 (52–66) | |||
| Range | 29–89 | 25–90 | 25–89 | |||
| <40 | 12 (0·9%) | 16 (1·2%) | 28 (2·0%) | |||
| 40–49 | 186 (13·7%) | 173 (12·7%) | 189 (13·8%) | |||
| 50–59 | 440 (32·3%) | 423 (30·9%) | 414 (30·3%) | |||
| 60–69 | 506 (37·2%) | 511 (37·4%) | 524 (38·3%) | |||
| 70–79 | 175 (12·9%) | 197 (14·4%) | 172 (12·6%) | |||
| ≥80 | 42 (3·1%) | 47 (3·4%) | 41 (3·0%) | |||
| Sex | ||||||
| Female | 1355 (99·6%) | 1365 (99·9%) | 1362 (99·6%) | |||
| Male | 6 (0·4%) | 2 (0·1%) | 4 (0·3%) | |||
| Unknown | 0 | 0 | 2 (0·1%) | |||
| Tumour grade | ||||||
| 1 | 315 (23·1%) | 315 (23·0%) | 300 (21·9%) | |||
| 2 | 660 (48·5%) | 663 (48·5%) | 690 (50·4%) | |||
| 3 | 386 (28·4%) | 389 (28·5%) | 378 (27·6%) | |||
| Risk group | ||||||
| Low (age ≥50 and grade 1 or 2) | 843 (61·9%) | 854 (62·5%) | 854 (62·4%) | |||
| High (age <50 or grade 3, or both) | 518 (38·1%) | 513 (37·5%) | 514 (37·6%) | |||
| Primary surgery | ||||||
| Breast conservation surgery | 1270 (93·3%) | 1278 (93·5%) | 1284 (93·9%) | |||
| Breast conservation surgery with oncoplastic technique | 42 (3·1%) | 33 (2·4%) | 42 (3·1%) | |||
| Mastectomy | 91 (6·7%) | 89 (6·5%) | 84 (6·1%) | |||
| Mastectomy with immediate reconstruction | 8 (0·6%) | 11 (0·8%) | 7 (0·5%) | |||
| Autologous reconstruction | 5/8 (62·5%) | 7/11 (63·6%) | 3/7 (42·9%) | |||
| Implant-based reconstruction | 2/8 (25·0%) | 4/11 (27·3%) | 4/7 (57·1%) | |||
| Reconstruction type not specified | 1/8 (12·5%) | 0 | 0 | |||
| Side of primary tumour | ||||||
| Left | 726 (53·3%) | 674 (49·3%) | 662 (48·4%) | |||
| Right | 635 (46·7%) | 693 (50·7%) | 704 (51·5%) | |||
| Unknown | 0 | 0 | 2 (0·1%) | |||
| Maximal extent of axillary staging | ||||||
| Sentinel node biopsy or guided axillary sampling | 1157 (85·0%) | 1184 (86·6%) | 1164 (85·1%) | |||
| Axillary clearance | 200 (14·7%) | 181 (13·2%) | 201 (14·7%) | |||
| Other | 4 (0·3%) | 2 (0·1%) | 1 (0·1%) | |||
| Unknown | 0 | 0 | 2 (0·1%) | |||
| Pathological node status | ||||||
| Positive | 257 (18·9%) | 243 (17·8%) | 256 (18·7%) | |||
| Negative | 1103 (81·0%) | 1124 (82·2%) | 1110 (81·1%) | |||
| Unknown | 1 (0·1%) | 0 | 2 (0·1%) | |||
| Histological type | ||||||
| Infiltrating ductal | 1084 (79·6%) | 1096 (80·2%) | 1086 (79·4%) | |||
| Lobular | 144 (10·6%) | 139 (10·2%) | 127 (9·3%) | |||
| Mixed | 51 (3·7%) | 63 (4·6%) | 65 (4·8%) | |||
| Other | 82 (6·0%) | 69 (5·0%) | 87 (6·4%) | |||
| Unknown | 0 | 0 | 3 (0·2%) | |||
| Pathological tumour size, cm | ||||||
| Median (IQR) | 1·6 (1·1–2·2) | 1·6 (1–2·2) | 1·6 (1·1–2·4) | |||
| Pathological T stage | ||||||
| T1mi | 4 (0·3%) | 5 (0·4%) | 6 (0·4%) | |||
| T1a | 69 (5·1%) | 68 (5·0%) | 51 (3·7%) | |||
| T1b | 258 (19·0%) | 270 (19·8%) | 256 (18·7%) | |||
| T1c | 612 (45·0%) | 601 (44·0%) | 602 (44·0%) | |||
| T2 | 394 (28·9%) | 389 (28·5%) | 424 (31·0%) | |||
| T3 | 21 (1·5%) | 30 (2·2%) | 25 (1·8%) | |||
| Unknown | 3 (0·2%) | 4 (0·3%) | 4 (0·3%) | |||
| ER and HER2 status | ||||||
| ER positive HER2 positive | 103 (7·6%) | 103 (7·5%) | 93 (6·8%) | |||
| ER positive HER2 negative | 1108 (81·4%) | 1130 (82·7%) | 1097 (80·2%) | |||
| ER negative HER2 positive | 32 (2·4%) | 34 (2·5%) | 42 (3·1%) | |||
| ER negative HER2 negative | 111 (8·2%) | 96 (7·0%) | 128 (9·4%) | |||
| Not known | 7 (0·5%) | 4 (0·3%) | 8 (0·6%) | |||
| Progesterone receptor status | ||||||
| Positive | 577 (73·1%)† | 541 (70·3%)† | 566 (69·8%)† | |||
| Negative | 212 (26·9%)† | 229 (29·7%)† | 245 (30·2%)† | |||
| Not done | 571 (42·0%) | 596 (43·6%) | 555 (40·6%) | |||
| Missing on form | 1 (0·1%) | 1 (0·1%) | 2 (0·1%) | |||
| Lymphovascular invasion | ||||||
| Present | 186 (13·7%) | 178 (13·0%) | 202 (14·8%) | |||
| Absent | 1085 (79·7%) | 1084 (79·3%) | 1055 (77·1%) | |||
| Uncertain | 34 (2·5%) | 40 (2·9%) | 51 (3·7%) | |||
| Unknown | 56 (4·1%) | 65 (4·8%) | 60 (4·4%) | |||
| Neoadjuvant chemotherapy received‡ | ||||||
| Yes | 48 (3·5%) | 56 (4·1%) | 43 (3·1%) | |||
| No | 1312 (96·4%) | 1311 (95·9%) | 1323 (96·7%) | |||
| Unknown | 1 (0·1%) | 0 | 2 (0·1%) | |||
| Adjuvant therapy received: all patients | ||||||
| Chemotherapy§ | 333/1360 (24·5%) | 324/1367 (23·7%) | 370/1366 (27·1%) | |||
| Adjuvant therapy received:‡ HER2-positive patients | ||||||
| Chemotherapy and trastuzumab | 84/135 (62·2%) | 85/137 (62·0%) | 100/135 (74·1%) | |||
| Trastuzumab, no chemotherapy | 16/135 (11·9%) | 13/137 (9·5%) | 13/135 (9·6%) | |||
| Chemotherapy, no trastuzumab | 2/135 (1·5%) | 2/137 (1·5%) | 0 | |||
| No chemotherapy, no trastuzumab | 33/135 (24·4%) | 37/137 (27·0%) | 22/135 (16·3%) | |||
| Adjuvant therapy received:‡ ER-positive patients | ||||||
| Endocrine therapy | 1169/1216 (96·1%) | 1186/1237 (95·9%) | 1157/1196 (96·7%) | |||
| Boost given | ||||||
| Yes | 342 (25·1%) | 337 (24·7%) | 332 (24·3%) | |||
| No | 1017 (74·7%) | 1027 (75·1%) | 1031 (75·4%) | |||
| Not known | 2 (0·1%) | 3 (0·2%) | 5 (0·4%) | |||
| Boost dose | ||||||
| 10 Gy in five fractions | 260/342 (76·0%) | 273/337 (81·0%) | 257/332 (77·4%) | |||
| 16 Gy in eight fractions | 80/342 (23·4%) | 64/337 (19·0%) | 75/332 (22·6%) | |||
| Unknown | 2/342 (0·6%) | 0 | 0 | |||
Data are n (%) or n/N (%) unless otherwise stated. ER=oestrogen receptor.
*
14 patients withdrew consent for any of their data to be used in analysis.
†
These percentages are calculated out of total patients who had available results for this test.
‡
Patients could have more than one type of adjuvant systemic therapy.
§
Chemotherapy type (for those specified): anthracyclines (n=584), taxane and anthracyclines (n=348), taxane and other—eg, docetaxel, carboplatin, and trastuzumab (n=83), and other (n=3).