Aspects of Adjuvant CDK4/6 Inhibitors in Older Breast Cancer Patients - Focusing on Geriatric Screening

Older breast cancer patients should not be categorically excluded from adjuvant therapies, including the recommended CDK4/6 inhibitors (CDK4/6i) administered in combination with endocrine therapy. Nevertheless, this population frequently presents with comorbidities that may increase susceptibility to treatment-related toxicities, including impacts on quality of life, which must be carefully considered when selecting therapeutic regimens. Given the limited representation of older patients in the clinical trials behind the recommendations for adjuvant CDK4/6i therapy, coupled with the uncertain magnitude of clinical benefit and the reported rates of toxicity and treatment discontinuation, it is essential to critically evaluate both efficacy and safety in this specific patient subgroup. National and international guidelines recommend the integration of geriatric assessments into routine clinical practice to facilitate individualized treatment decisions; however, such assessments are not yet widely implemented in many oncology departments and are not routinely in use to guide adjuvant CDK4/6i therapy. This study aims to investigate the implementation of geriatric assessments in older breast cancer patients (≥70 years) and to examine multiple dimensions of CDK4/6i treatment in this cohort, including short- and medium-term effects on quality of life, dose intensity, and clinical outcomes. By doing so, the investigators seek to more accurately delineate the benefits and risks of adjuvant CDK4/6i therapy in this specific patient population.

Inclusion Criteria: * ≥70 years old * Female/male * Completed surgery (primary or after neoadjuvant therapy) * Starting adjuvant CDK4/6i and endocrine therapy * Cognitive performance to be able answer questionaries * No language difficulties Exclusion Criteria: * Impaired cognitive function not able to understand the study intention or perform questionaries * Declining adjuvant CDK4/6i