Effect of breast-duct anatomy and wound-healing responses on local tumour recurrence after primary surgery for early breast cancer

Summary Despite the improvement in outcome for women with early breast cancer undergoing breast conservation surgery and radiotherapy, there are significant gaps in our understanding of local tumour relapse. In this Personal View, we propose two hypotheses: early-onset changes in breast-duct anatomy limit the degree of intraductal spread and explain much of the substantial age-related difference in risk of local tumour relapse; and wound-healing proteins stimulate the growth of cancer cells left behind after surgery. These mechanisms help to explain why generous surgical margins offer no greater protection against local tumour relapse than narrow margins after complete microscopic tumour excision.