Breast radiotherapy in elderly women: myths, controversies, and current techniques in the adjuvant setting

In developed countries, breast cancer (BC) is the most common type of cancer in women, mainly affecting patients over age 60. Due to the increasing life expectancy and population ageing, the incidence of BC is expected to increase significantly in the coming years. However, no standardized clinical guidelines are available to assist in decision-making in elderly patients. Moreover, there is a lack of quality scientific evidence to guide treatment selection in this patient population, who are underrepresented in clinical trials. Consequently, up to 50% of elderly women are treated suboptimally, which implies a worse prognosis and survival. Given that the current estimated life expectancy of a healthy 70-year-old woman is 15 years, any treatment capable of reducing the likelihood of disease recurrence and cancer-specific mortality in this patient population would be beneficial. Adjuvant radiotherapy (RT) is one of the pillars of treatment for BC and it plays a key role in improving local control (LC) and overall survival (OS). Adjuvant RT is clearly indicated in young patients who undergo breast-conserving surgery (BCS) as well as in high risk patients, regardless of age. However, the use of adjuvant RT in older patients with early-stage disease has decreased in recent years—even in patients who undergo BCS—due to outdated concerns about the possible side effects of RT and reports suggesting that RT can be omitted in low-risk patients. One of the greatest challenges currently facing radiation oncologists who specialise in the treatment of BC is the selection of elderly patients who are likely to benefit from adjuvant RT. There is also a clear need to critically evaluate the available evidence and to apply those findings to routine clinical practice. Given this context, the aim of the present review is to clarify the current role of adjuvant RT in the management of BC in older women—particularly those with early-stage disease—and to dispel the myths surrounding the use of RT to treat elderly women. This review primarily focuses on the indications, controversies, and irradiation techniques used in this patient subgroup.