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

Managing Doxorubicin Cardiotoxicity: Insights Into Molecular Mechanisms and Protective Strategies

Cancer ranks as the second leading cause of death in the United States and poses a significant health challenge globally. Numerous therapeutic options exist for treating cancer, with chemotherapy being one of the most prominent. Chemotherapy involves the use of antineoplastic drugs, either alone or in combination with other medications, to target and kill cancer cells. However, these drugs can also adversely affect healthy cells, leading to various side effects. Among the most commonly used chemotherapy agents are anthracyclines, which include doxorubicin, daunorubicin, and epirubicin. Doxorubicin is particularly notable for its effectiveness but is also associated with significant cardiotoxicity, a common concern for patients undergoing chemotherapy. Unfortunately, there is currently no definitive treatment to prevent or reverse this cardiotoxicity. The cardiac effects of doxorubicin can manifest in several ways, including changes in electrocardiograms, arrhythmias, myocarditis, pericarditis, myocardial infarction, cardiomyopathy, heart failure, and congestive heart failure. These complications may arise during treatment, shortly after it concludes, or even weeks later. Various mechanisms have been proposed to explain doxorubicin-induced cardiotoxicity. Key factors include the inhibition of topoisomerase IIβ, mitochondrial damage, reactive oxygen species (ROS) production due to iron metabolism, increased oxidative stress, heightened inflammatory responses, and elevated rates of apoptosis and necrosis within cardiac tissue. This review article will provide a comprehensive overview of the current state of knowledge regarding doxorubicin-induced cardiomyopathy. We will explore the underlying molecular mechanisms contributing to this condition and discuss emerging therapeutic strategies aimed at mitigating its impact on cancer survivors.

Mechanisms underlying dose-limiting toxicities of conventional chemotherapeutic agents

Dose-limiting toxicities (DLTs) are severe adverse effects that define the maximum tolerated dose of a cancer drug. In addition to the specific mechanisms of each drug, common contributing factors include inflammation, apoptosis, ion imbalances, and tissue-specific enzyme deficiencies. Among various DLTs are bleomycin-induced pulmonary fibrosis, doxorubicin-induced cardiomyopathy, cisplatin-induced nephrotoxicity, methotrexate-induced hepatotoxicity, vincristine-induced neurotoxicity, paclitaxel-induced peripheral neuropathy, and irinotecan, which elicits severe diarrhea. Currently, specific treatments beyond dose reduction are lacking for most toxicities. Further research on cellular and molecular pathways is imperative to improve their management. This review synthesizes preclinical and clinical data on the pharmacological mechanisms underlying DLTs and explores possible treatment approaches. A comprehensive perspective reveals knowledge gaps and emphasizes the need for future studies to develop more targeted strategies for mitigating these dose-dependent adverse effects. This could allow the safer administration of fully efficacious doses to maximize patient survival.

Cardioprotective strategies in the management of chemotherapy-induced cardiotoxicity: current approaches and future directions

Background

Chemotherapy-induced cardiotoxicity (CIC) is a significant challenge in cancer treatment, leading to heart failure and myocardial infarction. With rising cancer survival rates, the long-term cardiovascular health of survivors has gained importance. While several cardioprotective medications have been studied to mitigate chemotherapy's harmful effects on the heart, more research is needed to confirm their effectiveness and optimal use.

Methodology

This review synthesizes evidence on cardioprotective drugs in managing CIC. The authors conducted a comprehensive literature search of peer-reviewed articles, clinical trials, and meta-analyses published between January 2000 and May 2024. Studies were selected based on relevance, quality, and focus on mechanisms, efficacy, and clinical outcomes of cardioprotective agents such as beta-blockers, ACE inhibitors, ARBs, statins, and dexrazoxane.

Results and discussion

Cardioprotective medications show potential in alleviating the impact of chemotherapy on heart function. Beta-blockers and ACE inhibitors effectively reduce heart failure incidence and improve cardiac outcomes. Statins, with their anti-inflammatory and antioxidative properties, and dexrazoxane, which reduces anthracycline-induced cardiotoxicity, also show promise. However, variability in study designs, patient groups, and chemotherapy treatments complicates the establishment of standardized treatment protocols.

Conclusion

Cardioprotective drugs hold significant promise in managing CIC and improving cardiac outcomes for cancer patients. Current evidence supports the efficacy of beta-blockers, ACE inhibitors, statins, and dexrazoxane. Further research is needed to establish standardized protocols, evaluate long-term safety, and optimize treatment timing. Integrating cardioprotective strategies into oncological care can enhance the quality of life and prognosis for cancer survivors.

Efficacy and safety of cardioprotective drugs in chemotherapy-induced cardiotoxicity: an updated systematic review & network meta-analysis

BACKGROUND

Cancer patients receiving chemotherapy have an increased risk of cardiovascular complications. This limits the widespread use of lifesaving therapies, often necessitating alternate lower efficacy regimens, or precluding chemotherapy entirely. Prior studies have suggested that using common cardioprotective agents may attenuate chemotherapy-induced cardiotoxicity. However, small sample sizes and conflicting outcomes have limited the clinical significance of these results.

HYPOTHESIS

A comprehensive network meta-analysis using updated and high-quality data can provide more conclusive information to assess which drug or drug class has the most significant effect in the management of chemotherapy-induced cardiotoxicity.

METHODS

We performed a literature search for randomized controlled trials (RCTs) investigating the effects of cardioprotective agents in patients with chemotherapy-induced cardiotoxicity. We used established analytical tools (netmeta package in RStudio) and data extraction formats to analyze the outcome data. To obviate systematic bias in the selection and interpretation of RCTs, we employed the validated Cochrane risk-of-bias tools. Agents included were statins, aldosterone receptor antagonists (MRAs), ACEIs, ARBs, and beta-blockers. Outcomes examined were improvement in clinical and laboratory parameters of cardiac function including a decreased reduction in left ventricular ejection fraction (LVEF), clinical HF, troponin-I, and B-natriuretic peptide levels.

RESULTS

Our study included 33 RCTs including a total of 3,285 patients. Compared to control groups, spironolactone therapy was associated with the greatest LVEF improvement (Mean difference (MD) = 12.80, [7.90; 17.70]), followed by enalapril (MD = 7.62, [5.31; 9.94]), nebivolol (MD = 7.30, [2.39; 12.21]), and statins (MD = 6.72, [3.58; 9.85]). Spironolactone was also associated with a significant reduction in troponin elevation (MD =  - 0.01, [- 0.02; - 0.01]). Enalapril demonstrated the greatest BNP reduction (MD =  - 49.00, [- 68.89; - 29.11]), which was followed by spironolactone (MD =  - 16.00, [- 23.9; - 8.10]). Additionally, patients on enalapril had the lowest risk of developing clinical HF compared to the control population (RR = 0.05, [0.00; 0.75]).

CONCLUSION

Our analysis reaffirmed that statins, MRAs, ACEIs, and beta-blockers can significantly attenuate chemotherapy-induced cardiotoxicity, while ARBs showed no significant effects. Spironolactone showed the most robust improvement of LVEF, which best supports its use among this population. Our analysis warrants future clinical studies examining the cardioprotective effects of cardiac remodeling therapy in cancer patients treated with chemotherapeutic agents.

Ferulic acid mitigates diabetic cardiomyopathy via modulation of metabolic abnormalities in cardiac tissues of diabetic rats

Cardiovascular abnormalities have been reported as a major contributor of diabetic mortality. The protective effect of ferulic acid on diabetic cardiomyopathy in fructose-streptozotocin induced type 2 diabetes (T2D) rat model was elucidated in this study. Type 2 diabetic rats were treated by oral administration of low (150 mg/kg b.w) and high (300 mg/kg b.w) doses of ferulic acid. Metformin was used as the antidiabetic drug. Rats were humanely euthanized after 5 weeks of treatment, and their blood and hearts were collected. Induction of T2D depleted the levels of reduced glutathione, glycogen, and HDL-cholesterol and the activities of superoxide dismutase, catalase, ENTPDase, and 5'nucleotidase. It simultaneously triggered increase in the levels of malondialdehyde, total cholesterol, triglyceride, LDL-cholesterol, creatinine kinase-MB as well as activities of acetylcholinesterase, angiotensin converting enzyme (ACE), ATPase, glucose-6-phopsphatase, fructose-1,6-bisphophatase, glycogen phosphorylase, and lipase. T2D induction further revealed an obvious degeneration of cardiac muscle morphology. However, treatment with ferulic acid markedly reversed the levels and activities of these biomarkers with concomitant improvement in myocardium structural morphology, which had favorable comparison with the standard drug, metformin. Additionally, T2D induction led to the depletion of 40%, 75%, and 33% of fatty acids, fatty esters, and steroids, respectively, with concomitant generation of eicosenoic acid, gamolenic acid, and vitamin E. Ferulic acid treatment restored eicosanoic acid, 2-hydroxyethyl ester, with concomitant generation of 6-octadecenoic acid, (Z)-, cis-11-eicosenoic acid, tridecanedioic acid, octadecanoic acid, 2-hydroxyethyl ester, ethyl 3-hydroxytridecanoate, dipalmitin, cholesterol isocaproate, cholest-5-ene, 3-(1-oxobuthoxy)-, cholesta-3,5-diene. These results suggest the cardioprotective potential of ferulic acid against diabetic cardiomyopathy.

Cardiovascular Dysautonomia in Patients with Breast Cancer

Breast cancer is the most frequent malignant disease among women, being responsible for a considerable percentage of fatalities and comorbidities every year. Despite advances in early detection and therapy, evidence shows that breast cancer survivors are at increased risk of developing other chronic conditions, such as cardiovascular diseases.

Autonomic dysfunction is an emerging, but poorly understood topic that has been suggested as a risk factor for cardiovascular disease in breast cancer patients. It clinically manifests through persistently elevated heart rates and abnormal heart rate variability, even before any signs of cardiovascular dysfunction appear. Since changes in the left ventricular ejection fraction only manifest when myocardial injury has already occurred, it has been hypothesized that autonomic dysfunction can constitute an early biomarker of cardiovascular impairment in breast cancer patients.

This review focuses on the direct and indirect effects of cancer and its treatment on the autonomic nervous system in breast cancer patients. We highlight the mechanisms potentially involved in cancer and antineoplastic therapy-related autonomic imbalance and review the potential strategies to prevent and/or attenuate autonomic dysfunction.

There are gaps in the current knowledge; more research in this area is needed to identify the relevance of autonomic dysfunction and define beneficial interventions to prevent cardiovascular disease in breast cancer patients.

Cardioprotective Strategies from Cardiotoxicity in Cancer Patients: A Comprehensive Review

Cardiotoxicity is a significant complication of chemotherapeutic agents in cancer patients. Cardiovascular incidents including LV dysfunction, heart failure (HF), severe arrhythmias, arterial hypertension, and death are associated with high morbidity and mortality. Risk stratification of cancer patients prior to initiation of chemotherapy is crucial, especially in high-risk patients for cardiotoxicity. The early identification and management of potential risk factors for cardiovascular side effects seems to contribute to the prevention or minimization of cardiotoxicity. Screening of cancer patients includes biomarkers such as cTnI and natriuretic peptide and imaging measurements such as LV function, global longitudinal strain, and cardiac MRI. Cardioprotective strategies have been investigated over the last two decades. These strategies for either primary or secondary prevention include medical therapy such as ACE inhibitors, ARBs, b-blockers, aldosterone antagonists, statins and dexrazoxane, physical therapy, and reduction of chemotherapeutic dosages. However, data regarding dosages, duration of medical therapy, and potential interactions with chemotherapeutic agents are still limited. Collaboration among oncologists, cardiologists, and cardio-oncologists could establish management cardioprotective strategies and approved follow-up protocols in patients with cancer receiving chemotherapy.

Upregulation of Endothelin-1 May Predict Chemotherapy-Induced Cardiotoxicity in Women with Breast Cancer

As survival in breast cancer patients from newer therapies increases, concerns for chemotherapy-induced cardiotoxicity (CIC) have offset some of these benefits, manifesting as a decline in left ventricular ejection fraction (LVEF). Patients receiving anthracycline-based chemotherapy followed by trastuzumab are at risk for CIC. Previous research evaluating whether clinical biomarkers predict cardiotoxicity has been inconsistent. Recently, angiotensin II type 1 receptor (ATR1) and endothelin 1 (ET1) have been shown to play a role in breast tumor growth. We evaluated ATR1 and ET1 expression in breast cancer tissue and its association with CIC. A total of 33 paraffin-embedded breast tissue specimens from women with breast cancer treated with anthracycline-based chemotherapy and trastuzumab were analyzed by immunohistochemistry (IHC) and qRT-PCR. We found that ET1 expression was increased in patients with an LVEF ≤ 50% (p = 0.032) with a lower LVEF correlating with higher ET1 expression (r = 0.377, p = 0.031). In patients with a change in LVEF of greater than 10%, greater ET1 expression was noted compared to those without a change in LVEF (p = 0.017). Increased ET1 expression in breast tumor tissue is associated with reduced LVEF. Future studies need to examine whether ET1 may be a tissue biomarker that helps predict the risk of developing CIC in women with breast cancer.

Cardiac monitoring during trastuzumab therapy in metastatic breast cancer: early incidence of cardiac dysfunction

Trastuzumab therapy has dramatically changed breast cancer prognosis. Consensus documents recommend a close monitoring during therapy, not always feasible, especially in metastatic breast cancer. The purpose of this study is to describe trastuzumab cardiotoxicity in metastatic breast cancer patients to understand how to improve cardiovascular monitoring. We retrospectively studied metastatic breast cancer patients scheduled for trastuzumab therapy (2001-2018). All patients underwent a baseline evaluation and monitoring during therapy. Cardiotoxicity was defined as symptomatic heart failure or asymptomatic decrease in left ventricular ejection fraction > 10% from baseline and < 53%. Ninety-two women were included, mean age 61 years (±14.43), median follow-up 42.5 months (IQR 26-74). Fourteen percent developed cardiotoxicity:  two heart failure with preserved left ventricular ejection fraction, three heart failure with reduced left ventricular ejection fraction, and eight asymptomatic decreased in left ventricular ejection fraction. Eighty-one percent of cardiac dysfunction cases occurred within the first 4 years and on median of 31 months from trastuzumab initiation. Thus, in metastatic breast cancer patients, trastuzumab-mediated cardiotoxicity occurred more frequently during the first 4 years. These data should be considered to optimize follow-up protocols.

Detection of Subclinical Cardiovascular Disease by Cardiovascular Magnetic Resonance in Lymphoma Survivors

BACKGROUND

Long-term survivors of Hodgkin lymphoma (HL) and mediastinal non-Hodgkin lymphoma experience late adverse effects of radiotherapy and/or anthracycline-containing chemotherapy, leading to premature cardiovascular morbidity and mortality.

OBJECTIVES

The aim of this study was to identify markers for subclinical cardiovascular disease using cardiovascular magnetic resonance (CMR) in survivors of HL and non-Hodgkin lymphoma.

METHODS

CMR was performed in 80 lymphoma survivors treated with mediastinal radiotherapy with or without anthracyclines, and results were compared with those among 40 healthy control subjects matched for age and sex.

RESULTS

Of the 80 lymphoma survivors, 98% had histories of HL, the mean age was 47 ± 11 years, and 54% were male. Median radiotherapy dose was 36 Gy (interquartile range: 36-40 Gy), and radiotherapy was combined with anthracyclines in 70 lymphoma survivors (88%). Mean time between diagnosis and CMR was 20 ± 8 years. Significantly lower left ventricular (LV) ejection fraction (53% ± 5% vs 60% ± 5%; P < 0.001) and LV mass (47 ± 10 g/m2 vs 56 ± 8 g/m2; P < 0.001) and higher LV end-systolic volume (37 ± 8 mL/m2 vs 33 ± 7 mL/m2; P = 0.013) were found in lymphoma survivors. LV global strain parameters were also significantly worse in lymphoma survivors (P < 0.02 for all). Native myocardial T1 was significantly higher in lymphoma survivors compared with healthy control subjects (980 ± 33 ms vs 964 ± 25 ms; P = 0.007), and late gadolinium enhancement was present in 11% of the survivors.

CONCLUSIONS

Long-term lymphoma survivors have detectable changes in LV function and native myocardial T1 on CMR. Further longitudinal studies are needed to assess the implication of these changes in relation to treatment and clinical outcome.

Using Machine Learning Approaches to Predict Short-Term Risk of Cardiotoxicity Among Patients with Colorectal Cancer After Starting Fluoropyrimidine-Based Chemotherapy

Cardiotoxicity is a severe side effect for colorectal cancer (CRC) patients undergoing fluoropyrimidine-based chemotherapy. To develop and compare machine learning algorithms to predict cardiotoxicity risk among nationally representative CRC patients receiving fluoropyrimidine, CRC Patients with at least one claim of fluoropyrimidine after their cancer diagnosis were included. The outcome was the 30-day cardiotoxicity from the first day of starting fluoropyrimidine. The machine learning models including extreme gradient boosting (XGBoost), random forest (RF), and logistic regression (LR) were developed using 2006-2011 SEER-Medicare data, and model performances were evaluated using 2012-2014 data. Precision, F1 score, and area under the receiver operating characteristics curve (AUC) were measured to evaluate model performances. Feature importance plots were obtained to quantify the predictor importance. Among 36,030 CRC patients, 18.74% of them developed cardiotoxicity within 30 days since the first fluoropyrimidine. The XGBoost approach had better prediction performance with higher precision (0.619) and F1 score (0.406) in predicting the 30-day cardiotoxicity, compared to the RF (precision, 0.607 and F1 score, 0.395) and LR (precision, 0.610 and F1 score, 0.398). According to the DeLong's test for AUC difference, the XGBoost significantly outperformed the RF and LR (XGBoost, 0.816 vs. RF, 0.804, P < 0.001; XGBoost vs. LR, 0.812, P = 0.003, respectively). Feature importance plots identified pre-existing cardiac conditions, surgery, older age as top significant risk factors for cardiotoxicity events among CRC patients after receiving fluoropyrimidine. In summary, the developed machine learning models can accurately predict the occurrence of 30-day cardiotoxicity among CRC patients receiving fluoropyrimidine-based chemotherapy.

Heart Failure Therapies for the Prevention of HER2-Monoclonal Antibody-Mediated Cardiotoxicity: A Systematic Review and Meta-Analysis of Randomized Trials

Simple Summary

Monoclonal antibodies targeting HER2 are used for the management of early and metastatic HER2-positive breast cancer. Approximately 10–15% of patients diagnosed with breast cancer will be HER2-positive. The incidence of heart failure in breast cancer patients is becoming increasingly problematic, owing to the ageing of the population and the growing number of cancer survivors. The aim of our review was to assess the published evidence for the use of cardio-prevention strategies in HER2-monoclonal antibody-mediated cardiotoxicity. Whilst in the assessed trials the use of heart failure therapies did not reduce the risk of trastuzumab-associated cardiotoxicity, there was a reduction in the mean change in LVEF and in the rates of interruptions to HER2 therapy in patients treated with beta-blockers. This highlights the possible applications for neurohormonal therapies to prevent cardiotoxicity and mitigate interruption to vital HER2-monoclonal antibody treatment.

Abstract

Monoclonal antibodies including trastuzumab, pertuzumab, and antibody-drug conjugates, form the backbone of HER2-positive breast cancer therapy. Unfortunately, an important adverse effect of these agents is cardiotoxicity, occurring in approximately 10% of patients. There is increasing published data regarding prevention strategies for cardiotoxicity, though seldom used in clinical practice. We performed a systematic review and meta-analysis of randomized-controlled trials to evaluate pharmacotherapy for the prevention of monoclonal HER2-directed antibody-induced cardiotoxicity in patients with breast cancer. Online databases were queried from their inception until October 2021. Effects were determined by calculating risk ratios (RRs) and 95% confidence intervals (CI) or mean differences (MD) using random-effects models. We identified five eligible trials. In the three trials (n = 952) reporting data on the primary outcome of cardiotoxicity, there was no clear effect for patients assigned active treatment compared to control (RR = 0.90, 95% CI 0.63 to 1.29, p = 0.57). Effects were similar for ACE-I/ARB and beta-blockers (p homogeneity = 0.50). Active treatment reduced the risk of HER2 therapy interruptions (RR = 0.57, 95% CI 0.43 to 0.77, p < 0.001) with similar findings for ACE-I/ARB and beta-blockers (p homogeneity = 0.97). Prophylactic treatment with ACE-I/ARB or beta-blocker therapy may be of value for cardio-protection in patients with breast cancer prescribed monoclonal antibodies. Further, adequately powered randomized trials are required to define the role of routine prophylactic treatment in this patient group.

Anthracycline-free tumor elimination in mice leads to functional and molecular cardiac recovery from cancer-induced alterations in contrast to long-lasting doxorubicin treatment effects

Systemic effects of advanced cancer impact on the heart leading to cardiac atrophy and functional impairment. Using a murine melanoma cancer model (B16F10 melanoma cells stably transduced with a Ganciclovir (GCV)-inducible suicide gene), the present study analysed the recovery potential of cancer-induced cardiomyopathy with or without use of doxorubicin (Dox). After Dox-free tumor elimination and recovery for 70 ± 5 days, cancer-induced morphologic, functional, metabolic and molecular changes were largely reversible in mice previously bearing tumors. Moreover, grip strength and cardiac response to angiotensin II-induced high blood pressure were comparable with healthy control mice. In turn, addition of Dox (12 mg/kg BW) to melanoma-bearing mice reduced survival in the acute phase compared to GCV-alone induced recovery, while long-term effects on cardiac morphologic and functional recovery were similar. However, Dox treatment was associated with permanent changes in the cardiac gene expression pattern, especially the circadian rhythm pathway associated with the DNA damage repair system. Thus, the heart can recover from cancer-induced damage after chemotherapy-free tumor elimination. In contrast, treatment with the cardiotoxic drug Dox induces, besides well-known adverse acute effects, long-term subclinical changes in the heart, especially of circadian clock genes. Since the circadian clock is known to impact on cardiac repair mechanisms, these changes may render the heart more sensitive to additional stress during lifetime, which, at least in part, could contribute to late cardiac toxicity.

Cardioprotective medication use in Black and white breast cancer survivors

PURPOSE

Racial disparities in cardiovascular disease and cardiac dysfunction exist amongst breast cancer survivors. This study examined the prevalence of cardioprotective medication use in survivors and identified factors associated with use by race.

METHODS

The analysis included women enrolled in the Women's Hormonal Initiation and Persistence study, a longitudinal observational trial of breast cancer survivors. The study outcome, angiotensin converting enzyme inhibitor (ACEi) or ß-Blocker (BB) use, were ascertained from pharmacy records. Demographic, psychosocial, healthcare, and quality of life factors were collected from surveys and clinical data were abstracted from medical records. Bivariate associations by race and ACEi/BB use were tested using chi square and t tests; logistic regression evaluated multivariable-adjusted associations.

RESULTS

Of the 246 survivors in the sample, 33.3% were Black and most were < 65 years of age (58.4%). Most survivors were hypertensive (57.6%) and one-third received ACEi/BBs. In unadjusted analysis, White women (vs. Black) (OR 0.33, 95% 0.19-0.58) and women with higher ratings of functional wellbeing (OR 0.94, 95% 0.89-0.99) were less likely to use ACEi/BBs. Satisfaction with provider communication was only significant for White women. In multivariable-adjusted analysis, ACEi/BB use did not differ by race. Correlates of ACEi/BB use included hypertension among all women and older age for Black women only.

CONCLUSIONS

After adjusting for age and comorbidities, no differences by race in ACEi/BB use were observed. Hypertension was a major contributor of ACEi/BB use in BC survivors.

Prospective Evaluation of Doxorubicin Cardiotoxicity in Patients with Advanced Soft-tissue Sarcoma Treated in the ANNOUNCE Phase III Randomized Trial

PURPOSE

Few prospective studies have assessed anthracycline-associated cardiotoxicity in patients with sarcoma. We evaluated cardiotoxicity in patients with soft-tissue sarcomas administered doxorubicin in the phase III ANNOUNCE trial (NCT02451943).

PATIENTS AND METHODS

Patients were anthracycline-naïve adults with locally advanced or metastatic disease and left ventricular ejection fraction (LVEF) ≥50%. Patients could receive eight cycles of doxorubicin at 75 mg/m². The cardioprotectant, dexrazoxane, was allowed at investigator discretion. Symptomatic cardiac adverse events (AEs) were recorded using Medical Dictionary for Regulatory Activities and graded using Common Terminology Criteria for Adverse Events 4.0. LVEF deterioration was measured by echocardiogram or multigated acquisition scan, defined as a decrease to <50%, or decrease from baseline value >10%.

RESULTS

A total of 504 patients received ≥1 cycles of doxorubicin [median cumulative dose, 450.3 mg/m² (range, 72.3-634.0)]. Median follow-up of cardiac AEs was 28 weeks. Dexrazoxane was coadministered more frequently to patients receiving higher cumulative doxorubicin doses (38.6% receiving <450 mg/m², 88.5% receiving 450-<600 mg/m², and 90% receiving ≥600 mg/m²) and did not affect treatment efficacy. LVEF deterioration was seen in 62 of 153 (40.5%) patients who received a cumulative dose <450 mg/m², 82 of 159 patients (51.6%) who received 450-<600 mg/m², and 50 of 89 patients (56.2%) who received ≥600 mg/m². Grade ≥3 cardiac dysfunction occurred in 2% of patients at <450 mg/m², 3% at 450-<600 mg/m², and 1.1% at ≥600 mg/m². Incidence of treatment-related cardiac AEs was low across all dose ranges.

CONCLUSIONS

Although follow-up was short, these results suggest doxorubicin can be administered at high cumulative doses (>450 mg/m²), with a low rate of cardiotoxicities, in the context of dexrazoxane coadministration.See related commentary by Benjamin and Minotti, p. 3809.

Associations between initiating antihypertensive regimens on stage I-III colorectal cancer outcomes: A Medicare SEER cohort analysis

Purpose

Colorectal cancer (CRC) diagnosis is associated with high mortality in the United States and thus warrants the study of novel treatment approaches. Vascular changes are well observed in cancers and evidence indicates that antihypertensive (AH) medications may interfere with both tumor vasculature and in recruiting immune cells to the tumor microenvironment based on preclinical models. Extant literature also shows that AH medications are correlated with improved survival in some forms of cancer. Thus, this study sought to explore the impact of AH therapies on CRC outcomes.

Patients and Methods

This study was a non‐interventional, retrospective analysis of patients aged 65 years and older with CRC diagnosed from January 1, 2007 to December 31st, 2012 in the Surveillance, Epidemiology, and End‐Results (SEER)‐Medicare database. The association between AH drug utilization on AJCC stage I–III CRC mortality rates in patients who underwent treatment for cancer was examined using Cox proportional hazards models.

Results

The study cohort consisted of 13,982 patients diagnosed with CRC. Adjusted Cox proportional hazards regression showed that among these patients, the use of AH drug was associated with decreased cancer‐specific mortality (HR: 0.79, 95% CI: 0.75–0.83). Specifically, ACE inhibitors (hazard ratio [HR]: 0.84, 95% CI: 0.80–0.87), beta‐blockers (HR: 0.87, 95% CI: 0.84–0.91), and thiazide diuretics (HR: 0.83, 95% CI: 0.80–0.87) were found to be associated with decreased mortality. An association was also found between adherence to AH therapy and decreased cancer‐specific mortality (HR: 0.94, 95% CI: 0.90–0.98).

Conclusion

Further research needs to be performed, but AH medications may present a promising, low‐cost pathway to supporting CRC treatment for stage I–III cancers.

Clinical predictors of cardiac toxicity in HER2-positive early breast cancer patients treated with adjuvant s.c. versus i.v. trastuzumab

BACKGROUND

Few data are available about real-life cardiotoxicity associated with s.c. versus i.v. trastuzumab treatment of early-stage, HER2-positive breast cancer, and little is known about its predisposing factors.

PATIENTS AND METHODS

We retrospectively reviewed data of 363 adult patients treated with adjuvant trastuzumab for HER2-positive breast cancer. Univariate statistical analysis was performed, and a multivariable logistic model was developed to identify independent risk factors of cardiac toxicity.

RESULTS

Within 5 years, the overall incidence of events meeting our criteria was 11.8%, and an early discontinuation of trastuzumab was recorded in 20 patients (5.5%). No cases of congestive heart failure occurred, neither multiple events per patient were observed. A total of 184 patients received i.v. and 179 received s.c. trastuzumab. Compared with the s.c. formulation, a higher cardiotoxicity rate for the i.v. administration (15.2% vs 8.4%) was found, and particularly in those patients with cardiovascular risk factors (19.3% vs 8.7%), at the univariate and multivariate analyses. Although more patients with prior anthracycline-based chemotherapy experienced cardiac events, the association of this therapy with cardiac events was not significant. The incidence of cardiac events was not influenced by anthropometric data (e.g. body mass index) or a diagnosis of diabetes mellitus. 5-year event-free survival was 91.7% in the overall population; event-free survival rates were similar between the s.c. and the i.v. groups.

CONCLUSION

Our study shows a more favorable safety profile of s.c. versus i.v trastuzumab administration. The use of s.c. trastuzumab could be advisable in at-risk patients.

Doxorubicin-induced cardiotoxicity: An update on the molecular mechanism and novel therapeutic strategies for effective management

Doxorubicin (Dox) is a secondary metabolite of the mutated strain of Streptomyces peucetius var. Caesius and belongs to the anthracyclines family. The anti-cancer activity of Dox is mainly exerted through the DNA intercalation and inhibiting topoisomerase II enzyme in fast-proliferating tumors. However, Dox causes cumulative and dose-dependent cardiotoxicity, which results in increased risks of mortality among cancer patients and thus limiting its wide clinical applications. There are several mechanisms has been proposed for doxorubicin-induced cardiotoxicity and oxidative stress, free radical generation and apoptosis are most widely reported. Apart from this, other mechanisms are also involved in Dox-induced cardiotoxicity such as impaired mitochondrial function, a perturbation in iron regulatory protein, disruption of Ca²⁺ homeostasis, autophagy, the release of nitric oxide and inflammatory mediators and altered gene and protein expression that involved apoptosis. Dox also causes downregulation of DNA methyltransferase 1 (DNMT1) enzyme activity which leads to a reduction in the DNA methylation process. This hypomethylation causes dysregulation in the mitochondrial genes like peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1-alpha (PGC-1α), nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (TFAM) unit in the heart. Apart from DNA methylation, Dox treatment also alters the micro RNAs levels and histone deacetylase (HDAC) activity. Therefore, in the current review, we have provided a detailed update on the current understanding of the pathological mechanisms behind the well-known Dox-induced cardiotoxicity. Further, we have provided some of the most plausible pharmacological strategies which have been tested against Dox-induced cardiotoxicity.

Etiology and management of hypertension in patients with cancer

The pathophysiology of hypertension and cancer are intertwined. Hypertension has been associated with an increased likelihood of developing certain cancers and with higher cancer-related mortality. Moreover, various anticancer therapies have been reported to cause new elevated blood pressure or worsening of previously well-controlled hypertension. Hypertension is a well-established risk factor for the development of cardiovascular disease, which is rapidly emerging as one of the leading causes of death and disability in patients with cancer. In this review, we discuss the relationship between hypertension and cancer and the role that hypertension plays in exacerbating the risk for anthracycline- and trastuzumab-induced cardiomyopathy. We then review the common cancer therapies that have been associated with the development of hypertension, including VEGF inhibitors, small molecule tyrosine kinase inhibitors, proteasome inhibitors, alkylating agents, glucocorticoids, and immunosuppressive agents. When available, we present strategies for blood pressure management for each drug class. Finally, we discuss blood pressure goals for patients with cancer and strategies for assessment and management. It is of utmost importance to maintain optimal blood pressure control in the oncologic patient to reduce the risk of chemotherapy-induced cardiotoxicity and to decrease the risk of long-term cardiovascular disease.

Salidroside Attenuates Doxorubicin-Induced Cardiac Dysfunction Partially Through Activation of QKI/FoxO1 Pathway

Doxorubicin (DOX) is an effective chemotherapy. However, its usage has been associated with adverse effects. Salidroside (SAL) is an antioxidative drug, which confers protective effects against several diseases. Salidroside can attenuate cardiac dysfunction induced by DOX. Quaking (QKI) is identified as a protective factor that can inhibit cardiotoxicity medicated by DOX through the regulation of cardiac circular RNA expression. The present study investigated the role of QKI on the protective effect of SAL in the DOX-induced cardiotoxicity model. Results indicated that SAL attenuated DOX-induced adverse effects, including cardiac dysfunction, weight loss, and reactive oxygen species (ROS) production, and decreased the expression of BAX, caspase 3, and FoxO1. Also, it increased the Mn-SOD2 and QKI expression in vivo and in vitro. Furthermore, QKI knockdown suppressed anti-cardiotoxicity mediated by SAL. In conclusion, the results of the current study show that salidroside attenuates doxorubicin-induced cardiac dysfunction through activation of QKI/FoxO1 pathway.

Therapeutic Potentials of Selected Antihypertensive Agents and Their Fixed-Dose Combinations Against Trastuzumab-Mediated Cardiotoxicity

Trastuzumab (TZM) is useful in the clinical management of HER2-positive metastatic breast, gastric, and colorectal carcinoma but has been limited by its off-target cardiotoxicity. This study investigates the therapeutic potentials of 0.25 mg/kg/day amlodipine, 0.035 mg/kg/day lisinopril, 5 mg/kg/day valsartan, and their fixed-dose combinations in TZM-intoxicated Wistar rats that were randomly allotted into 10 groups of 6 rats for each group. Group I rats were treated with 10 ml/kg/day sterile water orally and 1 ml/kg/day sterile water intraperitoneally; Groups II, III, and IV rats were orally gavaged with 5 mg/kg/day valsartan and 1 ml/kg/day sterile water intraperitoneally, 0.25 mg/kg/day amlodipine and 1 ml/kg/day sterile water via the intraperitoneal route, 0.035 mg/kg/day lisinopril and 1 ml/kg/day sterile water administered intraperitoneally, respectively. Group V rats were orally treated with 10 ml/kg/day of sterile water prior to intraperitoneal administration of 2.25 mg/kg/day of TZM. Groups VI–VIII rats were equally pretreated with 5 mg/kg/day valsartan, 0.25 mg/kg/day amlodipine, and 0.035 mg/kg/day lisinopril before intraperitoneal 2.25 mg/kg/day TZM treatment, respectively; Groups IX and X rats were orally pretreated with the fixed-dose combinations of 0.25 mg/kg/day amlodipine +0.035 mg/kg/day lisinopril and 5 mg/kg/day valsartan +0.035 mg/kg/day lisinopril, respectively, before TZM treatment. Cardiac injury and tissue oxidative stress markers, complete lipids profile, histopathological, and immunohistochemical assays were the evaluating endpoints. Results showed that repeated TZM treatments caused profound increases in the serum TG and VLDL-c levels, serum cTnI and LDH levels, and cardiac tissue caspase-3 and -9 levels but decreased BCL-2 expression. TZM also profoundly attenuated CAT, SOD, GST and GPx activities, and increased MDA levels in the treated tissues. In addition, TZM cardiotoxicity was characterized by marked vascular and cardiomyocyte congestion and coronary artery microthrombi formation. However, the altered biochemical, histopathological, and immunohistochemical changes were reversed with amlodipine, lisinopril, valsartan, and fixed-dose combinations, although fixed-dose valsartan/lisinopril combination was further associated with hyperlipidemia and increased AI and CRI values and coronary artery cartilaginous metaplasia. Thus, the promising therapeutic potentials of amlodipine, lisinopril, valsartan and their fixed-dose combinations in the management of TZM cardiotoxicity, majorly mediated via antiapoptotic and oxidative stress inhibition mechanisms were unveiled through this study.

[Cytotoxic effect of photodynamic liposome gel combined with trastuzumab on drugresistant breast cancer cells in vitro]

OBJECTIVE

To evaluate the cytotoxic effect of photodynamic therapy (PDT) combined with targeted therapy using cross-linked liposomes and gels (Ce6-PC-Tmab@A-Gel) loaded with photosensitizer Chlorin (Ce6) and the tumor-targeting drug Trastuzumab (Tmab) in drug-resistant HER2+ breast cancer cells.

OBJECTIVE

Ce6-PC-Tmab liposomes were prepared using the thin-film hydration method. The general properties, encapsulation efficiency and near-infrared responsivity of the nanoparticles were evaluated. Ce6-PC-Tmab@A-Gel with a shear response was prepared by freeze drying and stirring crosslinking, and its microstructure was observed with scanning electron microscopy (SEM) and the shear response evaluated using a rheometer. The inhibitory effect of Ce6-PC-Tmab@A-Gel in drug-resistant HER2⁺ breast cancer SK-BR-3 cells was assessed with cytotoxicity assay (MTT assay) combined with near-infrared light.

OBJECTIVE

The particle size of Ce6-PC-Tmab was 239.7±9.7 nm and the potential was -2.03±0.09 mV. The entrapment efficiency of Tmab by Ce6-PC-Tmab liposomes was (40.22± 0.73)%. The prepared Ce6-PC-Tmab@A-Gel had a good shear response with excellent drug release characteristics under nearinfrared light, and increased intensity and duration of near-infrared light exposure enhanced Tmab release from the gel. Ce6-PC-Tmab@A-Gel was stable at room temperature and in a simulated tumor microenvironment (pH 6.25). Cytotoxicity assay (MTT) showed that Ce6-PC-Tmab@A-Gel combined with near-infrared light resulted in a survival rate of (31.37±1.73)% in SKBR-3 cells, much lower than that in the control group and other treatment groups (P < 0.01); the combined treatment also had a high efficiency of ROS production, and ROS release reached (22.36 ± 0.11)% after 2 min of near-infrared light exposure.

OBJECTIVE

The prepared Ce6-PC-Tmab@A-Gel has good near-infrared light response release characteristics to ensure effective targeted therapy with Tmab. The injectable gel system potentially allows long-term local drug release in the tumor to improve the treatment efficacy against drug-resistant breast cancer.

Red Blood Cell Distribution Width Is a Predictive Factor of Anthracycline-Induced Cardiotoxicity

Background: Red blood cell distribution width (RDW) is associated with prognosis in widespread cardiovascular fields, but little is known about relationship with the onset of cancer therapeutics-related cardiac dysfunction (CTRCD).

Objectives: The purpose of this study was to assess whether RDW could predict the onset of CTRCD by anthracycline.

Methods: Consequential 202 cancer patients planed for anthracycline treatment were enrolled and followed up for 12 months. The patients were divided into 2 groups based on the median value of baseline RDW before chemotherapy [low RDW group, n = 98, 13.0 [12.6–13.2]; high RDW group, n = 104, 14.9 [13.9–17.0]]. Cardiac function was assessed serially by echocardiography at baseline (before chemotherapy), as well as at 3, 6, and 12 months after chemotherapy with anthracycline.

Results: Baseline left ventricular end systolic volume index and ejection fraction (EF) were similar between two groups. After chemotherapy, EF decreased at 3- and 6-month in the high RDW group [baseline, 64.5% [61.9–68.9%]; 3-month, 62.6% [60.4–66.9%]; 6-month, 63.9% [60.0–67.9%]; 12-month, 64.7% [60.8–67.0%], P = 0.04], but no change was observed in low RDW group. The occurrence of CTRCD was higher in high RDW group than in low RDW group (11.5 vs. 2.0%, P = 0.008). When we set the cut-off value of RDW at 13.8, sensitivity and specificity to predict CTRCD were 84.6 and 62.0%, respectively. Multivariable logistic regression analysis revealed that baseline RDW value was an independent predictor of the development of CTRCD [odds ratio 1.390, 95% CI [1.09–1.78], P = 0.008]. The value of net reclassification index (NRI) and integrated discrimination improvement (IDI) for detecting CTRCD reached statistical significance when baseline RDW value was added to the regression model including known risk factors such as cumulative anthracycline dose, EF, albumin, and the presence of hypertension; 0.9252 (95%CI 0.4103–1.4402, P < 0.001) for NRI and 0.1125 (95%CI 0.0078–0.2171, P = 0.035) for IDI.

Conclusions: Baseline RDW is a novel parameter to predict anthracycline-induced CTRCD.

Cell Therapy Improves Cardiac Function in Anthracycline-Induced Cardiomyopathy Preclinical Models: A Systematic Review and Meta-Analysis

Although anthracycline (ANT)-based treatment strongly contributes to cancer survivorship, the use of these agents is limited by the risk of cardiotoxicity. For those patients who evolve to heart failure, myocardial regenerative approaches are of particular interest, and a growing body of preclinical studies has been investigating the use of cell therapy for ANT-induced cardiomyopathy (AIC). However, since animal models and modalities of cell therapy are highly heterogeneous between studies, the efficacy of cell therapy for AIC is not clear. Thus, we conducted a systematic review and meta-analysis of experimental studies reporting the use of cell therapy with mesenchymal stromal cells (MSC) or bone marrow mononuclear cells (BMMNC) in animal models of AIC with regard to global cardiac function. The Medline, EMBASE, and Web of Science databases were searched from inception to November 2019. Two reviewers independently extracted data on study quality and the results of left ventricular ejection fraction (LVEF) and fractional shortening (FS) obtained by echocardiography. The quality of outcomes was assessed using the Cochrane, Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies (CAMARADES), and SYRCLE bias risk tools. Pooled random-effects modeling was used to calculate pooled mean differences (MD) and 95% confidence intervals (CIs). Twenty-two studies comprising 381 small animals (rabbits and rodents) were included. A pooled meta-analysis of all treatments showed that cell therapy increased LVEF by 9.87% (95% CI 7.25-12.50, P < 0.00001) and FS by 7.80% (95% CI 5.68-9.92, P < 0.00001) in small animals with AIC. Cell therapy with MSC/BMMNC is effective to mitigate the deleterious effects of ANT on cardiac function in preclinical models. Nevertheless, due to the small number of studies and considerable heterogeneity, future translational studies must be designed to diminish between-study discrepancies and increase similarity to the clinical landscape.

What is considered cardiotoxicity of anthracyclines in animal studies

Anthracyclines are commonly used anticancer drugs with well-known and extensively studied cardiotoxic effects in humans. In the clinical setting guidelines for assessing cardiotoxicity are well-established with important therapeutic implications. Cardiotoxicity in terms of impairment of cardiac function is largely diagnosed by echocardiography and based on objective metrics of cardiac function. Until this day, cardiotoxicity is not an endpoint in the current general toxicology and safety pharmacology preclinical studies, although other classes of drugs apart from anthracyclines, along with everyday chemicals have been shown to manifest cardiotoxic properties. Also, in the relevant literature there are not well-established objective criteria or reference values in order to uniformly characterize cardiotoxic adverse effects in animal models. This in depth review focuses on the evaluation of two important echocardiographic indices, namely ejection fraction and fractional shortening, in the literature concerning anthracycline administration to rats as the reference laboratory animal model. The analysis of the gathered data gives promising results and solid prospects for both, defining anthracycline cardiotoxicity objective values and delineating the guidelines for assessing cardiotoxicity as a separate hazard class in animal preclinical studies for regulatory purposes.

Effects of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use on cancer therapy-related cardiac dysfunction: a meta-analysis of randomized controlled trials

Angiotensin-converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) may attenuate cancer therapy-related cardiac dysfunction (CTRCD). However, results of the previous studies were not consistent. We performed a meta-analysis to evaluate the influence of ACEI/ARB on CTRCD. Randomized controlled trials (RCTs) were obtained by searching of PubMed, Embase, and Cochrane's Library databases. A random-effect model was used to pool the results. Nine RCTs with 1095 cancer patients that underwent chemotherapy with anthracycline and/or trastuzumab were included. Using of ACEI/ARB significantly preserved left ventricular ejection fraction (LVEF, weighed mean difference = 4.24%, p = 0.002) compared with controls. Subgroup analyses showed that the benefits of ACEI/ARB on LVEF following chemotherapy were consistent and independent of study characteristics including study design, sample size, cancer type, chemotherapy protocols, preventative medications of ACEI or ARB, methods for LVEF measurement, and follow-up durations. The benefits on LVEF following chemotherapy were more remarkable in studies using ACEI and followed ≤ 12 months (p for subgroup difference = 0.04 and 0.02). Use of ACEI/ARB did not significantly reduce the risk of cardiotoxicity events (risk ratio [RR] = 0.63, p = 0.22) but increased the risk of hypotension in these patients (RR = 3.94, p = 0.008). These results indicated that using of ACEI/ARB may moderately attenuate CTRCD following chemotherapy with anthracycline and/or trastuzumab. Large-scale RCTs are needed to evaluate whether the benefits of ACEI/ARB on LVEF are clinically relevant.

Strategies to prevent anthracycline-induced cardiotoxicity in cancer survivors

Cancer diagnostics and therapies have improved steadily over the last few decades, markedly increasing life expectancy for patients at all ages. However, conventional and newer anti-neoplastic therapies can cause short- and long-term cardiotoxicity. The clinical implications of this cardiotoxicity become more important with the increasing use of cardiotoxic drugs. The implications are especially serious among patients predisposed to adverse cardiac effects, such as youth, the elderly, those with cardiovascular comorbidities, and those receiving additional chemotherapies or thoracic radiation. However, the optimal strategy for preventing and managing chemotherapy-induced cardiotoxicity remains unknown. The routine use of neurohormonal antagonists for cardioprotection is not currently justified, given the marginal benefits and associated adverse events, particularly with long-term use. The only United States Food and Drug Administration and European Medicines Agency approved treatment for preventing anthracycline-related cardiomyopathy is dexrazoxane. We advocate administering dexrazoxane during cancer treatment to limit the cardiotoxic effects of anthracycline chemotherapy.