CDK4/6 inhibitors for metastatic breast cancer in routine clinical practice in Spain: survey of patterns of use and oncologists' perceptions.

Abstract

Purpose: To assess the use of cyclin-dependent kinase 4/6 (CDK4/6) inhibitors in routine clinical practice in Spain, as well as the perceptions from oncologists.

Methods: A survey was developed by nine oncologists, experts in breast cancer, practising in Spain. Survey responses were collected between July 2022 and April 2023.

Results: Fifty-one survey responses were obtained. Most oncologists used CDK4/6 inhibitors in the first line. The first-line endocrine therapy most frequently used was an aromatase inhibitor (endocrine-sensitive disease) and fulvestrant (endocrine-resistant disease). CDK4/6 inhibitors were used for primary or secondary resistance, or visceral disease without visceral crisis. A lower-than-standard starting dose was considered (57% of respondents) for specific profiles. Strategies to manage toxicity included switching to another CDK4/6 inhibitor or delaying the next dose. CDK4/6 inhibitors were mostly considered to improve quality of life.

Conclusions: Use of CDK4/6 inhibitors in Spain follows current recommendations and aligns with the evidence.