Reimagining Deintensification for Low-Risk Breast Cancer.

As outcomes for low-risk breast cancer continue to improve, research and clinical paradigms are increasingly focused on appropriate deintensification with the goal of improving the therapeutic ratio of breast cancer treatment. These deintensification approaches span across disciplines including breast surgery, radiation therapy, and systemic therapy. With regard to breast surgery, studies have continued to push deintensification when it comes to surgical margins with breast conservation, reducing re-excision rates, whereas deintensification of axillary surgery has reduced the rates of axillary lymph node dissection and increasingly the need for any axillary surgery, including sentinel lymph node biopsy for low-risk patients. With regard to radiation therapy, studies have allowed for a drastic reduction in treatment duration, whereas approaches that reduce the target of treatment have led to a change from from treatment daily for 5-7 weeks to many low-risk patients completing treatment in just five treatments. With regard to systemic therapy, use of genomic assays and tumor biology has led to reduced utilization of cytotoxic chemotherapy, with studies also allowing for dose reduction of endocrine therapy for patients with ductal carcinoma in situ. Moving forward, greater focus should be placed on interdisciplinary deintensification approaches such as the consideration of radiation therapy alone as compared with endocrine therapy alone for low-risk breast cancers.