Radiotherapy after mastectomy.

Classic randomized trials documented the benefit of postmastectomy radiotherapy in women with node-positive or locally advanced breast cancer. Modern advances in surgical therapy, systemic therapy, and radiotherapy, however, along with an improved understanding of cancer biology, have called into question previously assumed recurrence risks and treatment benefits. This article explores the impact of tumor biology and genomic medicine on utilization of postmastectomy radiotherapy and how treatment decision making is moving beyond TNM-based predictors.