Current challenges and future perspectives of radiotherapy for locally advanced breast cancer.
OBJECTIVE
To discuss current issues in the field of radiation oncology for locally advanced breast cancer (LABC).


RESULTS
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.


CONCLUSIONS
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.
aDepartment of Radiation Oncology, University of Toronto bOdette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
Alireza Fotouhi
AF
Ghiam
Jacqueline
J
Spayne
Justin
J
Lee
D014408:Biomarkers, Tumor; D001943:Breast Neoplasms / Q000473:pathology* / Q000532:radiotherapy*; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D009367:Neoplasm Staging; D057285:Precision Medicine; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic
D014408:Biomarkers, Tumor