Chemotherapy in older patients with early breast cancer

The incidence of breast cancer increases with age. Particularly in ageing societies, breast cancer has a significant impact on both the older patient and the healthcare system. In older patients with early breast cancer, there is a complex interplay between (i) tumor biology, (ii) risk of recurrence, (iii) comorbidities, (iv) frailty, (v) life expectancy and (vi) patient expectations and preferences. Our treatment guidelines are often based on large meta-analyses that have shown that (neo)adjuvant chemotherapy improves the survival rate in early breast cancer in general. This is particularly important in triple-negative and HER2-positive breast cancer, but hormone receptor (HR)-positive, HER2-negative patients with a higher risk of recurrence also benefit from chemotherapy. However, most studies included younger and carefully selected patients. Since there is a positive correlation between age and estrogen receptor status, as well as between age and the number of concomitant diseases and the tolerability of chemotherapy, it is of great importance to evaluate the effects of additional (neo)adjuvant chemotherapy, especially in older patients with early-stage breast cancer. There are only a few studies in which only older patients with early breast cancer were included. On the whole, they show that older patients with HR-positive, HER2-negative tumors hardly benefit from chemotherapy in addition to endocrine therapy. In these patients, additional chemotherapy should be considered critically when weighing up the potential benefits and harms. However, this critical evaluation should not be confused with abandoning standard chemotherapy when it is feasible and clinically indicated based on geriatric assessment, risk assessment, and patient preference. The aim of our narrative review is to provide a concise overview of the evidence on chemotherapy in older women with breast cancer and place it in the context of geriatric assessment and risk evaluation in older HR-positive, HER2-negative patients with early breast cancer. This in turn should help to critically weigh up the risks and benefits of chemotherapy for the individual older patient with early-stage breast cancer, which should ultimately lead to more individualized and at the same time more evidence-based treatment recommendations that take into account the complex interplay of different and sometimes contradictory patient- and tumor-specific factors.