SNAC2: A randomised phase III study to determine in women with early breast cancer whether sentinel node based management increases the risk of loco-regional recurrence and in particular, axillary clearance, compared with axillary clearance with any subgroup of women

The Sentinel Node versus Axillary Clearance (SNAC) trial was the first, large, Australasian prospective assessment of the risk of lymphoedema after surgery for early breast cancer. The trial compared sentinel node biopsy of selected lymph nodes with clearance of axillary nodes in women with tumours smaller than 3 cm. Short-term results showed that arm swelling was less in the group having only sentinel node biopsy. Both treatment groups had moderate limitations in arm movement over the first 6 months, which then recovered to near normal levels. The results showed that for women with small tumours, sentinel node biopsy was a viable alternative to axillary clearance. The patients are being followed up so that long-term effects can be measured. Outcomes at 3 years will shortly be published. In SNAC 2, the investigators are recruiting women with large or multiple tumours in a more extensive trial with similar questions, which will allow any differences in subgroups of women to be analysed.