The overview by the Early Breast Cancer Trialists Collaborative Group on the impact of loco-regional treatments for breast cancer on long term survival was a milestone publication which partially clarified the significance of ipsilateral breast tumour recurrence (IBTR). In the aftermath of this overview, a conference was convened in London in October 2006 to discuss various aspects of IBTR and in particular whether this represents a marker or determinant of risk for distant metastases. An international panel of speakers covered a range of issues including biological paradigms, the effect of IBTR on survival and whether surgery itself can have a detrimental effect on patient outcome. Other topics included the limits to breast conserving surgery, systemic treatments for IBTR and the role of radiotherapy in minimising IBTR. It was concluded that IBTR is a determinant of distant relapse in approximately 25% of cases and a marker of risk in 75% of cases. However, current surgical practice should not favour increased rates of mastectomy on the basis of the recent meta-analysis of randomised trials.