Boost Irradiation to the Supraclavicular Area Among High Risk cN3c Breast Cancer Patients

This study is a phase II single-arm, prospective clinical trial aimed at assessing the efficacy and safety of RT boost to the SCV area among high-risk cN3c breast cancer patients contingent upon the nodal response after PST. Our previous retrospective study revealed that nodal response to PST serves as an independent prognostic factor for survival and pattern of failure. A cumulative SCV dose of ≥60 Gy has been associated with improved overall survival (OS) in subgroup of patients who did not achieve SCLN cCR. Based on nodal response to PST, patients will be categorized into three groups: those who did not achieve cCR in SCLN (considered high risk), those who achieved SCLN cCR but did not attain pCR in ALN (considered intermediate risk), and those who achieved cCR in SCLN and pCR in ALN (considered low risk). High-risk patients will undergo boost irradiation to the SCV with a cumulative dose of ≥60 Gy.