Treatment Sequencing in Metastatic HR+/HER2− Breast Cancer: A Delphi Consensus

Abstract

Metastatic breast cancer (mBC) carries a huge burden for patients and healthcare systems globally. Optimal treatment is of paramount importance to streamline the treatment journey. In HR+/HER2− mBC, at disease progression on first-line therapy, the choice of next treatment lines should be guided not only by the presence of specific targetable mutations, but also by evidence of efficacy and safety from clinical trials and access to genetic testing and medications. The aim of the Delphi process is to gain consensus (at least 70% agreement) on the perspective of treatment strategies from experts in the field. The outcome of Delphi discussions is an algorithm for the second line in HR+/HER2− mBC. Clinicians may find it useful in their current practice and use it as a basis for the treatment individualization strategy, which must remain the core principle of our actions. © 2025 by the authors.