Baseline Serum Albumin Is Associated With Severe Adverse Events During Trastuzumab Deruxtecan Treatment in Metastatic Breast Cancer

Background/Aim: Trastuzumab deruxtecan (T-DXd) is associated with a high incidence of severe adverse events (AEs); however, clinically useful baseline predictors of severe AEs are limited. This study aimed to explore factors associated with severe AEs in patients with metastatic breast cancer receiving T-DXd using least absolute shrinkage and selection operator (LASSO) regression. Patients and Methods: This single-center retrospective study included 31 patients with HER2-positive or HER2-low metastatic breast cancer who received T-DXd. Severe AEs were defined as grade ≥3 AEs. LASSO logistic regression was used to select candidate factors from 21 clinical and laboratory variables. Variables selected at λ1se were entered into multivariable logistic regression, and the optimal cutoff value was estimated using receiver operating characteristic (ROC) curve analysis.