Introduction
toxicity, breast cancer
SECONDARY, RECURRENCE, BREAST CANCER
The standard treatment for operable breast cancer is surgery. Some patients then also require adjuvant chemotherapy and radiotherapy. The largest trial to date, SECRAB, opened in 1998 when a wide range of chemoradiotherapy (CRT) schedules was used, with no evidence to favour sequential or synchronous protocols. The primary objective of this randomised phase III trial was to investigate whether local control could be improved by synchronous delivery of adjuvant chemotherapy and radiotherapy, not delaying the administration of either modality. This pragmatic trial recruited 2297 patients (1150 assigned to the synchronous arm and 1146 to the sequential arm) from 48 centres in the UK between 2 July 1998 and 25 March 2004. After 10 years of follow-up, SECRAB concluded that synchronous CRT significantly improves locoregional recurrence rates when compared with sequential chemotherapy followed by radiotherapy; 4.6% versus 7.1%, respectively (hazard ratio 0.62; 95% confidence interval 0.43, 0.90; Additional secondary endpoints of SECRAB included whether synchronous CRT could be given safely without enhancement of acute or late toxicity, or a significant reduction in chemotherapy dose intensity, as it has previously been acknowledged that the doses of chemotherapy received are rarely 100% of the projected dose due to toxicity [