Preoperative Radiation in Breast Cancer

Radiation plays a vital role in the management of breast cancer. Adjuvant radiation is integral part of treatment after breast conservation surgery. Early Breast Cancer Trialists’ Collaborative Group (EBCTCG) included 10,801 women with invasive breast cancer who underwent breast-conserving surgery with or without adjuvant radiation. Overall, the addition of adjuvant radiation lowered 10-year risk for locoregional or distant recurrence by 15.7% and 15-year risk for breast cancer death by 3.8% (p < 0.00001) [1]. This advantage was observed for both node-negative and node-positive cases. Overall, about one breast cancer death was avoided by year 15, and for every four recurrences avoided by year 10. In another meta-analysis of 8135 women, EBCTCG showed significantly reduced locoregional recurrence overall recurrence, and breast cancer mortality for patients with one to three positive nodes and for patients with four or more positive nodes. Earlier, a total of 50 Gy used to be delivered in 5 weeks, followed by an additional boost over 1.5 weeks. Such protracted courses often demotivate patients to opt for radiation, which leads to more mastectomies. Subsequently, it was realized that the breast has a low proliferation rate, and hypo-fractionated radiation slowly changed the revolutionized radiation in breast cancer. Understanding the pattern of failure also paved the way for partial breast radiation. However, with time, the introduction of oncoplastic surgery has posed some challenges for target delineation. In addition, efforts are being made to achieve higher pathological complete responses to improve disease control. Hence, it has been proposed to advocate radiation prior to surgery to help accurate target delineation, improve pCR rate, eliminate the detrimental effect of a hypoxic environment, etc. [2, 3].