Table 3.
Relapses, second primary cancers, and deaths by fractionation schedule (n=4096)
| 40 Gy in 15 fractions (n=1361) | 27 Gy in five fractions (n=1367) | 26 Gy in five fractions (n=1368) | ||
|---|---|---|---|---|
| Local tumour control event (primary endpoint)* | 31 (2·3%) | 27 (2·0%) | 21 (1·5%) | |
| Local relapse | 23 (1·7%) | 22 (1·6%) | 17 (1·2%) | |
| Ipsilateral breast, new primary | 6 (0·4%) | 3 (0·2%) | 4 (0·3%) | |
| Cannot differentiate | 2 (0·1%) | 2 (0·1%) | 0 | |
| Regional relapse | 13 (1·0%) | 11 (0·8%) | 10 (0·7%) | |
| Distant relapse | 59 (4·3%) | 69 (5·0%) | 76 (5·5%) | |
| Contralateral breast, second primary | 23 (1·7%) | 20 (1·5%) | 23 (1·7%) | |
| Invasive | 18 (1·3%) | 17 (1·2%) | 20 (1·5%) | |
| Ductal carcinoma in situ | 5 (0·4%) | 3 (0·2%) | 2 (0·1%) | |
| Unknown | 0 | 0 | 1 (0·1%) | |
| Non-breast, second primary | 42 (3·1%) | 37 (2·7%) | 44 (3·2%) | |
| Death | 92 (6·8%) | 105 (7·7%) | 90 (6·6%) | |
| Breast cancer† | 47 (3·5%) | 51 (3·7%) | 53 (3·9%) | |
| Second cancer | 12 (0·9%) | 16 (1·2%) | 10 (0·7%) | |
| Cardiac | 10 (0·7%) | 9 (0·7%) | 8 (0·6%) | |
| Other cause | 17 (1·7%) | 27 (2·0%) | 16 (1·2%) | |
| Unknown | 6 (1·2%) | 2 (0·1%) | 3 (0·2%) | |
Data are n (%). Patients reporting events of more than one type are included in each relevant row.
*
Includes angiosarcoma in ipsilateral breast (one in the 40 Gy group and two in the 26 Gy group) and six patients with ductal carcinoma in situ (three in the 40 Gy group, two in the 27 Gy group, and one in the 26 Gy group).
†
Includes 13 patients with distant relapse before death from other causes (four in the 40 Gy group, four in the 27 Gy group, and five in the 26 Gy group).