Results form the SECRAB trial suggest that sequential chemoradiotherapy is better at preventing recurrence, especially with anthracycline-CMF
SECRAB was a prospective, open-label, multi-centre, phase 3 trial comparing synchronous to sequential chemoradiotherapy, conducted in 48 UK centres.
Patients with invasive, early stage breast cancer (BCa) were stratified by centre, axillary surgery, chemotherapy, and radiotherapy boost. Permitted chemotherapy regimens included CMF and anthracycline-CMF.
Synchronous radiotherapy was administered between cycles two and three for CMF or five and six for anthracycline-CMF. Sequential radiotherapy was delivered on chemotherapy completion. Radiotherapy schedules included 40 Gy/15F over three weeks, and 50 Gy/25F over five weeks.
Between 2 July 1998 and 25 March 2004, 2297 patients were recruited (1150 synchronous and 1146 sequential).
With 10.2 years median follow-up, 10-year local recurrence rates were 4.6% and 7.1% in the synchronous and sequential arms respectively (hazard ratio (HR) 0.62; 95% CI 0.43-0.90; P=0.012).
In a sub-group analysis of anthracycline-CMF, the 10-year local recurrence rates difference were 3.5% vs 6.7%, respectively (HR 0.48; 95% CI 0.26-0.88; P=0.018).
There was no significant difference in overall or disease-free survival. One in four (24%) of patients on synchronous treat suffered moderate/severe acute skin reactions compared to 15% in the sequential arm (P<0.0001). There were no significant differences in late adverse effects apart from telangiectasia (P=0.03).
The authors concluded that synchronous chemoradiotherapy significantly improves local recurrence rates and this can be delivered with an acceptable increase in acute toxicity.
