Alopecia induced by CDK 4/6 Inhibitors and its Impact on the Quality of Life of Patients with advanced Breast cancer

Background Cyclin-dependent kinase (CDK) 4/6 inhibitors have revolutionized the management of hormone receptor-positive (HR+) advanced and metastatic breast cancer. However, CDK4/6 inhibitor-induced alopecia, a distinct and often underestimated adverse effect, can significantly impact patients' quality of life. This study aims to identify and quantify the severity of alopecia caused by CDK4/6 inhibitors and its effect on quality of life using validated assessment tools. Methods This cross-sectional, single-center study included 51 female breast cancer patients treated with CDK4/6 inhibitors for at least three months, as first line for metastatic disease. Alopecia severity was graded using the Common Terminology Criteria for Adverse Events (CTCAE) grading scale, while the impact on quality of life was assessed through the Hair-Specific Skindex-29 questionnaire. Statistical analysis included t-tests, ANOVA, Chi-square tests, and linear regression to identify predictors of quality-of-life impairment. Results Nearly half of the participants (49%) developed alopecia, with 26% graded as CTCAE grade I and 23% as grade II. Higher CTCAE grades were associated with significantly worse Hair-Specific Skindex-29 scores in the emotions, symptoms, and functional capacity subsections (p < 0.05). Regression analysis showed that both the CTCAE grade and the specific CDK4/6 inhibitor used were significant predictors of overall quality-of-life impairment. Conclusion This study is the first to quantify the impact of CDK4/6 inhibitor-induced alopecia on quality of life in the MENA (Middle East and North Africa) region, showing that greater alopecia severity leads to more symptoms, and worse emotional and functional well-being.