Systemic treatment for hormone receptor-positive/HER2-negative advanced/metastatic breast cancer: A review of European real-world evidence studies

This review examined patterns of systemic anticancer treatment in patients with HR+ /HER2- metastatic breast cancer in real-world clinical practice in Europe since 2016 to assess whether they reflect clinical guidelines and recent changes in available treatment options. We identified 30 publications for inclusion. In studies evaluating patients up to the end of 2017, endocrine therapy predominated, with endocrine monotherapy typically used in 45-65 % of patients. More recent studies suggested that use of cyclin-dependent kinase 4/6 inhibitor therapy has gained ground since European approval in late 2016, with two studies reporting first-line use in over 55 % of patients. Chemotherapy was typically used first line in 25-45 % of patients, although current guidelines recommend endocrine therapy in the absence of a visceral crisis. In conclusion, our review suggests that the most recent treatment developments for patients with HR+ /HER2 - metastatic breast cancer are being reflected in the changing treatment patterns seen in real-world practice.