Locoregional Therapy: From Mastectomy to Reconstruction, Targeted Surgery, and Ultra-Hypofractionated Radiotherapy.

Background: The past 3 decades have seen an unprecedented shift toward treatment de-escalation in surgical therapy of breast cancer. Summary: Radical mastectomy has been replaced by breast-conserving and oncoplastic approaches in most patients, and full axillary lymph node dissection by less radical staging procedures, such as sentinel lymph node biopsy and targeted axillary dissection. Further, attempts have been made to spare healthy tissue while increasing the probability of removing the tumor with clear margins, thus improving cosmetic results and minimizing the risk of local recurrence. In this context, modern probe-guided localization techniques have been introduced to guide surgical excision. This progress was accompanied by the development of targeted systemic therapies. At the same time, radiotherapy for breast cancer has undergone significant changes. The use of hypofractionation has decreased the typical length of a treatment course from 5-6 weeks to 1-3 weeks. Partial breast irradiation is now a valid option for de-escalation in patients with low-risk features. Axillary radiotherapy achieves similar recurrence rates and decreases the risk of lymphedema in patients with limited sentinel node involvement. Key Messages: Taken together, these advances are important steps toward individualization of locoregional management strategies. This highlights the importance of interdisciplinary approaches for de-escalation of locoregional therapies.