The Role of Vasospasm and Microcirculatory Dysfunction in Fluoropyrimidine-Induced Ischemic Heart Disease

Anticancer-Drug-Related Cardiotoxicity from Adjuvant Goserelin and Tamoxifen Therapy

Background: Breast cancer is a prevalent malignancy with rising incidence globally. Advances in endocrine therapy have improved outcomes for premenopausal women with hormone receptor-positive breast cancer. However, these treatments may induce menopause-like states, potentially elevating cardiovascular risks, including left ventricular (LV) dysfunction. This study aims to evaluate the impact of one year of adjuvant endocrine therapy with goserelin and tamoxifen on LV function in premenopausal breast cancer patients. Methods: The ISACS cardiovascular toxicity (NCT01218776) is a pilot multicenter registry of breast cancer patients referred to hospitals for routine surveillance, suspected, or confirmed anticancer-drug-related cardiotoxicity (ADRC). Patients may be enrolled retrospectively (1 year) and prospectively. The pilot phase focused on the available data on combined goserelin and tamoxifen therapy for breast cancer and its impact on LV disfunction at 1-year follow-up. Inverse probability of treatment weighting (IPTW) analysis of the ISACS registry was performed assigning 70 patients to combined endocrine therapy (goserelin and tamoxifen). Controls consisted of 120 patients with no adjuvant combined goserelin and tamoxifen therapy. None of the patients developed distant metastasis. Primary outcome measures were as follows: low LV function in women as defined by a left ventricular ejection fraction (LVEF) < 65% and subclinical LV dysfunction as defined by a 10-percentage point decrease in LVEF. Results: In the overall population, combined goserelin and tamoxifen therapy did not affect the mean LV function compared with controls at 3-, 6-, and 12-month follow-up (65.7 ± 2.7% versus 65.3 ± 2.1%, p value = 0.27; 65.5 ± 2.9% versus 65.1 ± 2.5%, p value = 0.34; 65.0 ± 3.2% versus 64.6 ± 3.1%, p value = 0.29, respectively). The mean LVEF reduction in patients who did or did not receive combination therapy for 12 months was small and approximately similar (1.03 ± 2.5% versus 1.16 ± 2.9%, p value = 0.73). Using IPTW analyses, there were no significant associations between combined therapy and low LV function (risk ratio [RR]: 1.75; 95% CI: 0.71-4.31) or subclinical LV dysfunction (RR: 1.50; 95% CI: 0.35-6.53) compared with controls. Conclusions: One year of endocrine therapy with goserelin and tamoxifen does not cause ADRC in patients with invasive breast cancer. Findings are independent of the severity of the disease. Results may not be definitive without replication in studies with larger sample size.

Effect of chemotherapy in tumor on coronary arteries: Mechanisms and management

Coronary artery disease (CAD) is an important contributor to the cardiovascular burden in cancer survivors. The development of coronary ischemia events, myocardial infarction, and heart failure has been associated with many conventional chemotherapeutic agents, new targeted therapies, and immunotherapy. The most frequent pathological manifestations of chemotherapy-mediated coronary damage include acute vasospasm, acute thrombosis, accelerated atherosclerosis development, and microvascular dysfunction. Potential screening techniques for CAD patients include baseline risk factor evaluation, polygenic risk factors, and coronary artery calcium scores. Determining the risk requires consideration of both the type of chemotherapy and the type of cancer being treated. Cardiology-oncology guidelines offer some suggestions for the care of coronary artery disease, which might involve medication, lifestyle changes, and coronary revascularization.

The Metformin Immunoregulatory Actions in Tumor Suppression and Normal Tissues Protection

The immune system is the key player in a wide range of responses in normal tissues and tumors to anticancer therapy. Inflammatory and fibrotic responses in normal tissues are the main limitations of chemotherapy, radiotherapy, and also some newer anticancer drugs such as immune checkpoint inhibitors (ICIs). Immune system responses within solid tumors including anti-tumor and tumor-promoting responses can suppress or help tumor growth. Thus, modulation of immune cells and their secretions such as cytokines, growth factors and epigenetic modulators, pro-apoptosis molecules, and some other molecules can be suggested to alleviate side effects in normal tissues and drug-resistance mechanisms in the tumor. Metformin as an anti-diabetes drug has shown intriguing properties such as anti-inflammation, anti-fibrosis, and anticancer effects. Some investigations have uncovered that metformin can ameliorate radiation/chemotherapy toxicity in normal cells and tissues through the modulation of several targets in cells and tissues. These effects of metformin may ameliorate severe inflammatory responses and fibrosis after exposure to ionizing radiation or following treatment with highly toxic chemotherapy drugs. Metformin can suppress the activity of immunosuppressive cells in the tumor through the phosphorylation of AMP-activated protein kinase (AMPK). In addition, metformin may stimulate antigen presentation and maturation of anticancer immune cells, which lead to the induction of anticancer immunity in the tumor. This review aims to explain the detailed mechanisms of normal tissue sparing and tumor suppression during cancer therapy using adjuvant metformin with an emphasis on immune system responses.

Impaired microvascular reactivity in patients treated with 5-fluorouracil chemotherapy regimens: Potential role of endothelial dysfunction

Background

5-fluorouracil (5-FU) is the second most common cancer chemotherapy associated with short- and long-term cardiotoxicity. Although the mechanisms mediating these toxicities are not well understood, patients often present with symptoms suggestive of microvascular dysfunction. We tested the hypotheses that patients undergoing cancer treatment with 5-FU based chemotherapy regimens would present with impaired microvascular reactivity and that these findings would be substantiated by decrements in endothelial nitric oxide synthase (eNOS) gene expression in 5-FU treated human coronary artery endothelial cells (HCAEC).

Methods

We first performed a cross-sectional analysis of 30 patients undergoing 5-FU based chemotherapy treatment for cancer (5-FU) and 32 controls (CON) matched for age, sex, body mass index, and prior health history (excluding cancer). Cutaneous microvascular reactivity was evaluated by laser Doppler flowmetry in response to endothelium-dependent (local skin heating; acetylcholine iontophoresis, ACh) and -independent (sodium nitroprusside iontophoresis, SNP) stimuli. In vitro experiments in HCAEC were completed to assess the effects of 5-FU on eNOS gene expression.

Results

5-FU presented with diminished microvascular reactivity following eNOS-dependent local heating compared to CON (P = 0.001). Iontophoresis of the eNOS inhibitor L-NAME failed to alter the heating response in 5-FU (P = 0.95), despite significant reductions in CON (P = 0.03). These findings were corroborated by lower eNOS gene expression in 5-FU treated HCAEC (P < 0.01) compared to control. Peak vasodilation to ACh (P = 0.58) nor SNP (P = 0.39) were different between groups.

Conclusions

The present findings suggest diminished microvascular function along the eNOS-NO vasodilatory pathway in patients with cancer undergoing treatment with 5-FU-based chemotherapy regimens and thus, may provide insight into the underlying mechanisms of 5-FU cardiotoxicity.

Circulating Biomarkers for Monitoring Chemotherapy-Induced Cardiotoxicity in Children

Most commonly diagnosed cancer pathologies in the pediatric population comprise leukemias and cancers of the nervous system. The percentage of cancer survivors increased from approximatively 50% to 80% thanks to improvements in medical treatments and the introduction of new chemotherapies. However, as a consequence, heart disease has become the main cause of death in the children due to the cardiotoxicity induced by chemotherapy treatments. The use of different cardiovascular biomarkers, complementing data obtained from electrocardiogram, echocardiography cardiac imaging, and evaluation of clinical symptoms, is considered a routine in clinical diagnosis, prognosis, risk stratification, and differential diagnosis. Cardiac troponin and natriuretic peptides are the best-validated biomarkers broadly accepted in clinical practice for the diagnosis of acute coronary syndrome and heart failure, although many other biomarkers are used and several potential markers are currently under study and possibly will play a more prominent role in the future. Several studies have shown how the measurement of cardiac troponin (cTn) can be used for the early detection of heart damage in oncological patients treated with potentially cardiotoxic chemotherapeutic drugs. The advent of high sensitive methods (hs-cTnI or hs-cTnT) further improved the effectiveness of risk stratification and monitoring during treatment cycles.

Tales from the future-nuclear cardio-oncology, from prediction to diagnosis and monitoring

Cancer and cardiovascular diseases (CVD) often share common risk factors, and patients with CVD who develop cancer are at high risk of experiencing major adverse cardiovascular events. Additionally, cancer treatment can induce short- and long-term adverse cardiovascular events. Given the improvement in oncological patients' prognosis, the burden in this vulnerable population is slowly shifting towards increased cardiovascular mortality. Consequently, the field of cardio-oncology is steadily expanding, prompting the need for new markers to stratify and monitor the cardiovascular risk in oncological patients before, during, and after the completion of treatment. Advanced non-invasive cardiac imaging has raised great interest in the early detection of CVD and cardiotoxicity in oncological patients. Nuclear medicine has long been a pivotal exam to robustly assess and monitor the cardiac function of patients undergoing potentially cardiotoxic chemotherapies. In addition, recent radiotracers have shown great interest in the early detection of cancer-treatment-related cardiotoxicity. In this review, we summarize the current and emerging nuclear cardiology tools that can help identify cardiotoxicity and assess the cardiovascular risk in patients undergoing cancer treatments and discuss the specific role of nuclear cardiology alongside other non-invasive imaging techniques.

Diagnosis and Management of Cancer Treatment-Related Cardiac Dysfunction and Heart Failure in Children

It is disheartening for parents to discover that their children have long-term cardiac dysfunction after being cured of life-threatening childhood cancers. As the number of childhood cancer survivors increases, early and late oncology-therapy-related cardiovascular complications continues to rise. It is essential to understand that cardiotoxicity in childhood cancer survivors is persistent and progressive. A child's cancer experience extends throughout his lifetime, and ongoing care for long-term survivors is recognized as an essential part of the cancer care continuum. Initially, there was a lack of recognition of late cardiotoxicities related to cancer therapy. About 38 years ago, in 1984, pioneers like Dr. Lipshultz and others published anecdotal case reports of late cardiotoxicities in children and adolescents exposed to chemotherapy, including some who ended up with heart transplantation. At that time, cardiac tests for cancer survivors were denied by insurance companies because they did not meet appropriate use criteria. Since then, cardio-oncology has been an emerging field of cardiology that focuses on the early detection of cancer therapy-related cardiac dysfunction occurring during and after oncological treatment. The passionate pursuit of many healthcare professionals to make life better for childhood cancer survivors led to more than 10,000 peer-reviewed publications in the last 40 years. We synthesized the existing evidence-based practice and described our experiences in this review to share our current method of surveillance and management of cardiac dysfunction related to cancer therapy. This review aims to discuss the pathological basis of cancer therapy-related cardiac dysfunction and heart failure, how to stratify patients prone to cardiotoxicity by identifying modifiable risk factors, early detection of cardiac dysfunction, and prevention and management of heart failure during and after cancer therapy in children. We emphasize serial longitudinal follow-ups of childhood cancer survivors and targeted intervention for high-risk patients. We describe our experience with the new paradigm of cardio-oncology care, and collaboration between cardiologist and oncologist is needed to maximize cancer survival while minimizing late cardiotoxicity.