De-Escalation of Adjuvant Radiotherapy in Early Breast Cancer: Progress and Perspectives Following Breast-Conserving Surgery

Clinical evidence has shown that breast-conserving surgery combined with postoperative radiotherapy has become the standard treatment for patients with early-stage breast cancer, significantly reducing the rate of local-regional recurrence. However, conventional radiotherapy protocols require daily treatments over several consecutive weeks, which not only increase the economic burden on patients but also are associated with significant radiotherapy-related adverse effects. Acutely, these adverse effects mainly manifest as skin reactions in the treated area, breast tissue edema, and cancer-related fatigue. In the long term, there may be subsequent tissue damage, including radiation dermatitis, telangiectasia, breast fibrosis, and chronic pain. Notably, existing studies have suggested that some low-risk subgroups of patients (e.g., the elderly, those with favorable tumor biological characteristics, negative surgical margins, and those who have received standardized systemic therapy) have limited survival benefits from adjuvant radiotherapy. Therefore, the safety and feasibility of postoperative radiotherapy exemption for specific low-risk populations urgently need further validation.