69 Assessing the Impact and Efficacy of Anthracyclines and Trastuzumab Alternatives on Potential Cardiotoxicity in Breast Cancer Patients

Background

Cardiotoxicity is an important factor of long-term outcomes in breast cancer, particularly among patients treated with anthracyclines and HER2-targeted therapies. Under physiologic conditions, HER2 heterodimerization with HER4 activates various pathways essential for mitochondrial integrity, sarcomere stability, and protection from oxidative injury in the cardiac system. This review evaluates mechanistic, clinical, and therapeutic evidence regarding the cardiotoxic effects of anthracyclines and trastuzumab as well as the efficacy of emerging alternatives designed to reduce cardiac risk.

Materials and Methods

A structured keyword search of PubMed, Embase, Google Scholar, and Cochrane databases was used to identify relevant studies analyzing the impact of breast cancer therapies on cardiac function and the cardiac safety and efficacy of alternative treatments. Search terms focused on HER2-positive breast cancer populations, cardiotoxicity associated with anthracycline- and trastuzumab-based therapies, and alternative HER2-directed treatment strategies.

Results

Anthracyclines instigate cardiotoxicity through cumulative oxidative stress, mitochondrial injury, and topoisomerase IIβ–mediated DNA damage, leading to progressive left ventricular dysfunction. Trastuzumab compounds this risk by inhibiting HER2-mediated neuregulin-1 signaling, impairing myocardial recovery after anthracycline exposure. Sequential or combined use of these agents is associated with the highest incidence of left ventricular systolic dysfunction, often manifesting years after therapy completion.

To mitigate these risks, multiple strategies have emerged. Anthracycline-free regimens, such as taxane-platinum combinations with trastuzumab, maintain oncologic efficacy while significantly reducing cardiotoxicity. Modified anthracyclines, including liposomal doxorubicin and epirubicin, limit myocardial exposure without compromising breast cancer control. New HER2-directed therapies, including pertuzumab-trastuzumab combination therapy and antibody-drug conjugates such as ado-trastuzumab emtansine and fam-trastuzumab deruxtecan-nxki, offer potent efficacy with markedly improved cardiovascular safety compared with traditional anthracycline–trastuzumab sequences. Additionally, adjunctive cardioprotective agents, including angiotensin receptor blockers, β-blockers, and statins, further reduce therapy-induced myocardial injury and enable continuation of HER2-targeted treatment even in patients with preexisting dysfunction. Collectively, these approaches reflect a paradigm shift toward cardio-conscious cancer care, balancing survival benefits with long-term cardiovascular safety.

Conclusion

Modern breast cancer treatments prioritize anthracycline-sparing regimens and safer HER2-targeted agents compared with trastuzumab, reducing cardiac risk without compromising efficacy. Furthermore, early risk stratification using biomarkers and imaging, combined with adjunctive cardioprotective therapies, enables continuation of life-prolonging treatment in patients with breast cancer. Beyond survival, preserving and improving quality of life is critical; minimizing cardiotoxicity reduces long-term morbidity, supports functional independence, and enhances overall well-being. These integrated approaches highlight the importance of cardio-oncology in achieving effective cancer control alongside optimal survivorship outcomes.