Abstract
Background: Early indicators of cardiotoxicity during trastuzumab treatment are desirable for risk assessment. Oxidative stress and inflammation are potential contributors to the cardiotoxic process, but early inflammatory markers at treatment initiation are not well investigated.
Aims: To investigate whether high-sensitivity C-reactive protein, myeloperoxidase and interleukin-6 measured at trastuzumab initiation are associated with deterioration in global longitudinal strain, left ventricular ejection fraction or the development of cardiotoxicity.
Methods: A post hoc analysis of blood samples from a single-center prospective cohort involving 45 human epidermal growth factor receptor 2 (HER2) - positive breast cancer patients treated with trastuzumab. Blood samples were collected before trastuzumab initiation and on days 3, 7 and 14, and evaluated in mixed model for repeated measures and logistic regression model.
Results: No significant association was found between elevated combined biomarker levels and global longitudinal strain (p = 0.17) or left ventricular ejection fraction (p = 0.18), nor for individual biomarkers. Results from the regression analysis were divergent, with high-sensitivity C-reactive protein negatively associated with mild cardiotoxicity at visit 3 (OR = 0.92, p = 0.041), interleukin-6 negatively associated with moderate and clinical cardiotoxicity at visit 3 (OR = 0.95, p = 0.041 and OR = 0.96, p = 0.036, respectively), but positively associated with moderate and clinical cardiotoxicity at visit 4 (OR = 1.14, p = 0.047 and OR = 1.08, p = 0.032, respectively). Myeloperoxidase showed no significant associations.
Conclusion: High-sensitivity C-reactive protein, myeloperoxidase and interleukin-6 are not reliable early predictors of cardiotoxicity during trastuzumab treatment in this cohort. Larger studies are needed to clarify their relevance in cardiotoxicity risk assessment.