Past

Historically, patients with mastectomy were told they would not require radiation therapy—indeed, it was one of the considerations for opting for mastectomy over breast conserving approaches. With the emergence of the Denmark and British Columbia trials demonstrating a survival advantage to post-mastectomy radiation therapy (PMRT) for node positive patients1,2 and a plethora of data to suggest that PMRT reduces local recurrence rates and breast cancer specific mortality,3 practitioners became much more liberal in their use of this modality. Indeed, major consensus panels advocated for the same.4 But radiation is not without toxicity—both physical and financial—and so the question arises, can we tailor the use of radiation therapy such that it is given only to those patients who will truly benefit from it?

Present

With the increasing use of genomic assays and neoadjuvant therapy to predict prognosis, some wonder about whether decisions regarding PMRT could be personalized to individual patients. In an effort to reduce toxicity, there is currently a move to de-escalate therapy from both a surgical as well as a radiation therapy perspective, particularly when it comes to management of the axilla. Lymphedema remains a concern for many patients with overly aggressive treatment but the need for optimal local control weighs on the minds of many multidisciplinary teams. The debate continues as to which modality can provide optimal local control while minimizing toxicity.5 While both surgeons and radiation oncologists seem keen to do less, avoiding both modalities may compromise oncologic control.

Future

Clinical trials are ongoing that hope to provide some data to answer the question of how we can “right size” local therapy for individual patients. Until data from these trials can provide insight to guide our management, there remains a delicate balance between the risks and the benefits of PMRT in T1/2N1 breast cancer patients, and the debate over these issues persists.