Current challenges and future perspectives of radiotherapy for locally advanced breast cancer

Purpose of review To discuss current issues in the field of radiation oncology for locally advanced breast cancer (LABC). Recent findings Large randomized studies involving nodal irradiation have recently been completed. The incremental benefit of treating the internal mammary nodes (IMNs) remains controversial. A randomized study specifically evaluating internal mammary node radiation (IMNR) failed to demonstrate significant benefit. A high impact, population-based study detected a proportional increase in major coronary events with increasing radiation dose. Advanced treatment techniques should be employed to reduce cardiac exposure. In patients with stage IV breast cancer (BCa), there is increasing evidence to suggest that locoregional treatments may improve overall survival (OS). Radiotherapy alone, without surgery, may provide equivalent local control and OS in patients with distant metastasis. High-dose stereotactic radiation regimens can be used to treat breast tumors with good local control rates in as few as three visits. BCa biomarkers are predictive of locoregional recurrence risk and should be used to guide radiotherapy in conjunction with standard staging. Clinically validated genetic profiling can measure tumor radiosensitivity and also help to predict normal tissue toxicity. Summary We are entering an era of personalized radiotherapy for LABC. Radiation treatments must be tailored to each individual patient's risk and intrinsic tumor biology.