Radiotherapy decisions across age groups in early-stage breast cancer

Background: Breast-conserving surgery (BCS) followed by adjuvant radiotherapy (RT) remains the standard of care for early-stage breast cancer (ESBC), supported by decades of randomized trials demonstrating reduced local recurrence and improved survival. Recent advances in radiobiology, molecular profiling, and treatment delivery have expanded the range of RT options, allowing for more personalized, risk-adapted approaches. Objective: This review aims to summarize and critically evaluate current radiotherapy strategies for ESBC, with a focus on hypofractionated regimens, radiotherapy omission, and the influence of patient age on treatment selection and outcomes. Content: We discuss the clinical evidence supporting moderate and ultra-hypofractionated RT schedules, including long-term results from the START and FAST-Forward trials, and highlight the gradual adoption of these regimens into practice. We examine barriers to widespread implementation, such as concerns about long-term toxicity in younger patients and financial disincentives in certain healthcare systems. The review also explores RT omission in low-risk elderly patients, emphasizing ongoing debates surrounding adherence to endocrine therapy, patient quality of life, and evolving trial data. Age-specific considerations, including differences in tumor biology, life expectancy, and treatment tolerance, are integrated throughout the discussion to underscore the need for individualized treatment planning. In this context, it is important to consider the side effects of hormonal therapy, as younger women may experience greater impacts on fertility, sexual health, and daily functioning, while older women are more prone to bone loss, joint pain, and metabolic effects, all of which influence quality of life and adherence to treatment. Conclusions: As evidence continues to support shorter and more targeted RT regimens, clinical practice must adapt to balance efficacy, safety, and patient-centered outcomes. Treatment decisions should increasingly reflect patient-specific factors rather than age alone. Ongoing trials and extended follow-up will further refine these approaches, advancing the paradigm of personalized radiotherapy in early breast cancer.