[Mechanisms of cardiotoxicity of oncological therapies]

The cardio-oncologic burden of breast cancer: molecular mechanisms and importance of preclinical models

Breast cancer, the most prevalent cancer affecting women worldwide, poses a significant cardio-oncological burden. Despite advancements in novel therapeutic strategies, anthracyclines, HER2 antagonists, and radiation remain the cornerstones of oncological treatment. However, each carries a risk of cardiotoxicity, though the molecular mechanisms underlying these adverse effects differ. Common mechanisms include DNA damage response, increased reactive oxygen species, and mitochondrial dysfunction, which are key areas of ongoing research for potential cardioprotective strategies. Since these mechanisms are also essential for effective tumor cytotoxicity, we explore tumor-specific effects, particularly in hereditary breast cancer linked to BRCA1 and BRCA2 mutations. These genetic variants impair DNA repair mechanisms, increase the risk of tumorigenesis and possibly for cardiotoxicity from treatments such as anthracyclines and HER2 antagonists. Novel therapies, including immune checkpoint inhibitors, are used in the clinic for triple-negative breast cancer and improve the oncological outcomes of breast cancer patients. This review discusses the molecular mechanisms underlying BRCA dysfunction and the associated pathological pathways. It gives an overview of preclinical models of breast cancer, such as genetically engineered mouse models, syngeneic murine models, humanized mouse models, and various in vitro and ex vivo systems and models to study cardiovascular side effects of breast cancer therapies. Understanding the underlying mechanism of cardiotoxicity and developing cardioprotective strategies in preclinical models are essential for improving treatment outcomes and reducing long-term cardiovascular risks in breast cancer patients.

[Cardiooncology-usefulness of cardiac MRI : Inflammation, fibrosis, outcome]

BACKGROUND

With rapidly increasing survival chances of cancer patients, the potential side effects of cancer therapeutics are increasingly relevant and a potentially lifelong issue. If cardiotoxic effects are not detected at a reversible stage, this might result in irreversible heart failure.

OBJECTIVES

This article will portray the current state of knowledge on the use of cardiac magnetic resonance imaging (cardiac MRI) in the field of cardio-oncology. The aim is to provide an overview of the advantages of cardiac MRI to determine myocardial function and analyze inflammatory or fibrotic myocardial changes.

MATERIALS AND METHODS

Current studies on this topic were collected and evaluated. Expert recommendations from various position papers were reviewed and summarized. Lastly, an MRI protocol to assess potential cardiotoxic effects of cancer therapeutics was discussed.

RESULTS

Up to 20% of patients are reported to suffer from cancer therapeutics-related cardiac dysfunction (CTRCD). Especially those with cardiovascular risk factors should receive pre- and posttherapeutic monitoring of heart function. Cardiac MRI is currently suggested as an imaging tool to analyze myocardial function if echocardiographic assessment is insufficient. However, cardiac MRI is also an excellent method for additional tissue analysis.

CONCLUSION

Current consensus statements recommend cardiac MRI as optional in cases where echocardiography image quality is not adequate. Nevertheless, patients with reduced heart function on echocardiography might benefit from early assessment of inflammatory or fibrotic changes due to CTRCD using cardiac MRI.