Cardiovascular Effects of Chemotherapy Used in the Treatment of Breast Cancers

Cardiovascular Health Considerations for Primary Care Physicians Treating Breast Cancer Survivors

Breast cancer (BC) survivors are at increased risk for cardiovascular disease (CVD) and require their primary care physicians to manage their long-term general medical care, including cardiovascular (CV) health. Yet, evidence exists that some primary care physicians possess insufficient knowledge about survivorship care. With the goal of bridging these knowledge gaps, a PubMed review was conducted from July 7, 2020, through October 2, 2020, with an updated PubMed review from January 3, 2024, through April 28, 2024, focusing on CV health considerations in the primary care of BC survivors. Search terms included variations of "breast cancer survivors" and "cardiovascular." In total, 152 publications were included. Breasts cancer survivors may have increased CVD risk because some anticancer therapies are cardiotoxic and risk factors for BC often also increase the risk for CVD. Multiple risk factors overlap for BC and CVD such as older age, Western diet, early menarche, physical inactivity, high body mass index, and smoking. In this review, results are summarized from studies that report the presence of CV risk factors and CVD in BC survivors. Also described are the CV effects of BC therapies (chemotherapy, hormonal agents, targeted therapies, and radiotherapy) and the type of CV evaluation (cardiac imaging and measurement of biomarkers) that these patients may need. Primary care physicians have an important role in managing the CV health of BC survivors from preventing, assessing, and managing CV risk factors to referring patients to appropriate specialists when needed.

Near-infrared light-triggered synergistic antitumor therapy based on hollow ZIF-67-derived Co3S4-indocyanine green nanocomplex as a superior reactive oxygen species generator

Reactive oxygen species (ROS) with strong oxidability have been considered as effective agents for antitumor therapy through oxidative damage to lipids, proteins, DNA and RNA. In this work, a multifunctional hollow cobaltosic sulfide (Co₃S₄)/photosensitizer indocyanine green (ICG) nanocomplex (Co₃S₄-ICG) has been synthesized by efficiently loading ICG into the hollow Co₃S₄ to realize synergistic antitumor therapy via chemodynamic therapy (CDT), photodynamic therapy (PDT) and photothermal therapy (PTT) under near-infrared (808 nm) laser irradiation. Co₃S₄ nanoparticles would be degraded in tumor acidic microenvironment into Co²⁺, which locally triggers a Fenton-like reaction to produce cytotoxic hydroxyl radicals (OH) for CDT. Co₃S₄-ICG could also produce singlet oxygen (¹O₂) through a multi-step photochemical process for PDT under 808 nm laser irradiation. The slow release of ICG in the tumor region was achieved due to hollow-structured Co₃S₄ working as nanocarriers, and which has been proved an effective approach for combined CDT/PDT. In addition, Co₃S₄-ICG showed high photothermal conversion efficiency (40.5%) for PTT, and excellent OH generation capability via photothermal-improved Fenton reaction, leading to the synergistically improved antitumor efficacy. In vitro and in vivo experimental results confirm that the combined PTT/PDT/photothermal-enhanced CDT therapy can effectively ablate tumors with a negligible systemic toxicity. This work provides a valuable strategy for designing and constructing of a multifunctional nanoplatform for synergistic antitumor therapy of solid tumors.

The Preventive Role of Angiotensin Converting Enzyme Inhibitors/Angiotensin-II Receptor Blockers and β-Adrenergic Blockers in Anthracycline- and Trastuzumab-Induced Cardiotoxicity

Anthracycline (doxorubicin) and trastuzumab treatments for cancer patients have been known to cause cardiotoxicity. The current recommendations for prevention of cardiac events from cancer chemotherapies are largely based on opinion. The American Society of Clinical Oncology recommends active screening and prevention of modifiable cardiovascular risk factors. The risk factors are defined as tobacco use, high blood pressure, high cholesterol, alcohol use, obesity, and physical inactivity. Beta-adrenergic blockers and angiotensin converting enzyme (ACE) inhibitors/angiotensin receptor blockers (ARBs) have been the mainstay of treatment for heart failure patients with reduced left ventricular ejection fraction for many years. This review analyzed the use of beta-adrenergic blockers and ACE inhibitors/ARBs as protection against cardiomyopathy caused by anthracyclines and trastuzumab. Although many more studies are warranted, it was concluded that the addition of a beta-blocker early in the treatment of cancer patients who are undergoing anthracycline or trastuzumab treatment can have beneficial effects in preserving left ventricular ejection fraction and preventing chemotherapy-induced cardiotoxicity. The effects are more apparent in the short term. More studies of the long-term effects are warranted, as are the additive effects of using a beta-blocker and ACE inhibitor/ARB together to prevent chemotherapy-induced cardiotoxicity.

Cardiotoxicity of Cancer Therapies

Cardiotoxicity is a known complication of many cancer therapies. While the cardiotoxicity of established agents such as anthracyclines, antimetabolites, and alkylating agents is well known, it is important to realize that newer anticancer therapies such as tyrosine kinase inhibitors, angiogenesis inhibitors, and checkpoint inhibitors are also associated with significant adverse cardiovascular effects. Echocardiography, magnetic resonance imaging, and radionuclide imaging have been used to identify these complications early and prevent further consequences. We will discuss the different classes of cancer therapeutic agents that cause cardiotoxicity, the mechanisms that lead to these effects, and strategies that can be used to prevent the cardiac morbidity and mortality associated with their use.

Aromatase inhibitors and risk of cardiovascular events in breast cancer patients: a systematic review and meta-analysis

BACKGROUND

Cardiovascular events (CVEs) was considered as one of the primary cause to reduce the quality of life in breast cancer patients with aromatase inhibitors (AIs) treatment, which has not been sufficiently addressed. The aim of this study was to assess the correlation between risk of CVEs and AIs in patients with breast cancer.

METHODS

Included studies were obtained from the databases of Embase, Pubmed, Cochrane Library, Clinical Trials.gov, and reference lists. The main outcome measures were overall incidence, odds ratios (ORs), and 95% confidence intervals (CIs). Furthermore, the association and the risk differences among different tumor types, AIs,ages,or treatment regimens were conducted. Fixed-effect or random-effect models were applied in the statistical analyses according to the heterogeneity. Our analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

RESULTS

Seventeen studies, which included 44,411 subjects, were included in our analyses. The overall incidence of CVEs in AIs group was 13.02% (95% CI: 8.15-20.17%) and almost all of the high-grade CVEs occurred in patients treated with AIs. The pooled ORs of CVEs was 0.9940 (95% CI: 0.8545-1.1562). Under sub-group analysis, the incidence of CVEs related to exemestane was higher than that of controls (OR = 1.1564, 95% CI: 1.0656-1.2549), but no statistical differences in risk of CVEs were found in other sub-group analysis. No evidence of publication bias was found for incidence of CVEs in our meta-analysis by a funnel plot.

CONCLUSIONS

These results suggest that patients with breast cancer treated with AIs do not have a significant risk of developing CVEs in comparison with the controls, and exemestane might not be considered as the alternative AI to the breast cancer patients from the perspective of CVEs. Further studies are recommended to investigate this association and the risk differences among different tumor types, AIs or treatment regimens.