According to research presented at the European Multidisciplinary Cancer Congress, the use of synchronous chemoradiation is associated with a lower risk of recurrence compared to sequential therapy in the treatment of early breast cancer.  This was however a subanalysis; there was no statistically significant difference between treatments in the primary endpoint of locoregional recurrence. 

Sequential adjuvant therapy (chemotherapy followed by radiotherapy) has been the standard of care for the treatment of early breast cancer; this study sought to determine whether synchronous chemoradiation (use of radiotherapy during or in between cycles of chemotherapy) could improve outcomes compared to this standard.  The multicentre SECRAB (Sequencing of Chemotherapy and Radiotherapy in Adjuvant Breast Cancer) study included 2,296 women with early breast cancer who underwent mastectomy or breast conserving surgery and were then randomised to synchronous or sequential chemoradiation (with CMF or anthracycline-CMF chemotherapy). 

The primary endpoint was locoregional recurrence – there was no difference between the groups with respect to this (5.4% with synchronous and 7.4% with sequential; p=0.19). When the analysis was limited to patients with local recurrence, there was however a difference in favour of synchronous therapy (2.8% versus 5.1%; p=0.03) [the study would not however have been powered for this endpoint, as it was a subgroup analysis].  The report goes on to note that synchronous therapy was not superior to sequential therapy for a number of other outcomes tested, including overall and progression-free survival, and that there was no evidence of any differences on quality of lofe, despite synchronous therapy being shorter.  

There was a higher risk of moderate or severe radiation-associated skin toxicity in the synchronous group (24% versus 15%); the researchers did however comment that they are now using more modern ways of delivering radiotherapy, so lower skin reactions would be expected than those seen in this study, which ran between 1998 and 2004.