Cardiac toxicity in breast cancer survivors: review of potential cardiac problems

Dual-target inhibitors based on ERα: Novel therapeutic approaches for endocrine resistant breast cancer

Estrogen receptor alpha (ERα), a nuclear transcription factor, is a well-validated therapeutic target for more than 70% of all breast cancers (BCs). Antagonizing ERα either by selective estrogen receptor modulators (SERMs) or selective estrogen receptor degraders (SERDs) forms the foundation of endocrine therapy and has achieved great success in the treatment of ERα positive (ERα+) BCs. Unfortunately, despite initial effectiveness, endocrine resistance eventually emerges in up to 30% of ERα+ BC patients and remains a significant medical challenge. Several mechanisms implicated in endocrine resistance have been extensively studied, including aberrantly activated growth factor receptors and downstream signaling pathways. Hence, the crosstalk between ERα and another oncogenic signaling has led to surge of interest to develop combination therapies and dual-target single agents. This review briefly introduces the synergisms between ERα and another anticancer target and summarizes the recent advances of ERα-based dual-targeting inhibitors from a medicinal chemistry perspective. Accordingly, their rational design strategies, structure-activity relationships (SARs) and biological activities are also dissected to provide some perspectives on future directions for ERα-based dual target drug discovery in BC therapy.

Diet Quality and All-Cause Mortality in Women with Breast Cancer from the Breast Cancer Family Registry

BACKGROUND

The impact of diet on breast cancer survival remains inconclusive. We assessed associations of all-cause mortality with adherence to the four diet quality indices: Healthy Eating Index-2015 (HEI-2015), Alternative Healthy Eating Index (AHEI), Alternative Mediterranean Diet (aMED), and Dietary Approaches to Stop Hypertension (DASH).

METHODS

Dietary intake data were evaluated for 6,157 North American women enrolled in the Breast Cancer Family Registry who had been diagnosed with invasive breast cancer from 1993 to 2011 and were followed through 2018. Pre-diagnosis (n = 4,557) or post-diagnosis (n = 1,600) dietary intake was estimated through a food frequency questionnaire. During a median follow-up time of 11.3 years, 1,265 deaths occurred. Cox proportional hazards models were used to estimate multivariable-adjusted HR and 95% confidence intervals (CI).

RESULTS

Women in the highest versus lowest quartile of adherence to the HEI-2015, AHEI, aMED, and DASH indices had a lower risk of all-cause mortality. HR (95% CI) were 0.88 (0.74-1.04; Ptrend = 0.12) for HEI-2015; 0.82 (0.69-0.97; Ptrend = 0.02) for AHEI; 0.73 (0.59-0.92; Ptrend = 0.02) for aMED; and 0.78 (0.65-0.94; Ptrend = 0.006) for DASH. In subgroup analyses, the associations with higher adherence to the four indices were similar for pre- or post-diagnosis dietary intake and were confined to women with a body mass index <25 kg/m2 and women with hormone receptor positive tumors.

CONCLUSIONS

Higher adherence to the HEI-2015, AHEI, aMED, and DASH indices was associated with lower mortality among women with breast cancer.

IMPACT

Adherence to a healthy diet may improve survival of women with breast cancer.

Clinical management of drug-induced cardiotoxicity in patients with HER-2+ breast cancer: current recommendations and future outlook

INTRODUCTION

Human epidermal growth factor receptor two (HER2) target therapies have drastically revolutionised the treatment of HER2-positive breast cancer. Starting with trastuzumab, early phase III trials have already highlighted its significant cardiotoxicity, which is also present, albeit to a lesser extent, in the new generation drugs. Also given the growing population of patients with cardiovascular diseases, it is vital to set up proper long-term follow-up to prevent morbidity related to the development of cardiotoxicity.

AREAS COVERED

This review discusses the mechanisms of action underlying the cardiotoxicity of HER2 targeted therapies and the main clinical evidence on the toxicity of these drugs. In addition, the patterns of patient assessment prior to the initiation of therapy with HER2 targeted therapies are discussed, as well as the main evidence concerning the follow-up and management of cardiotoxicity.

EXPERT OPINION

the mechanisms of cardiotoxicity of new HER2 drugs need further study and, likewise, methods to prevent, monitor and identify HER-2-induced cardiotoxicity need to be implemented. Although some studies highlight the validity of cardiac biomarkers as predictive factors for cardiotoxicity, their actual usefulness and timing is still debated. Further studies are needed to assess the effectiveness of possible pharmacological primary prevention.

Prognostic value of left ventricular global longitudinal strain on speckle echocardiography for predicting chemotherapy-induced cardiotoxicity in breast cancer patients: A systematic review and meta-analysis

BACKGROUND

Literature suggests that left ventricular global longitudinal strain (LV-GLS) on speckle echocardiography has the potential to predict cardiotoxicity amongst breast cancer patients receiving chemotherapy such as anthracycline, taxane, cyclophosphamide, and trastuzumab. Our study aimed to collect evidence for the prognostic value of LV-GLS for predicting chemotherapy-induced cardiotoxicity in breast cancer patients.

METHODS

A detailed search of the PubMed, Google Scholar, Cochrane Library, and Scopus databases was conducted for published articles up to August 31, 2022. In our meta-analysis, we looked at 13 studies with a total of 1007 breast cancer patients getting chemotherapy that looked at the predictive value of GLS.

RESULTS

Absolute GLS change during treatment showed a pooled sensitivity of 84% (95% CI 74% to 91%) and a pooled specificity of 77% (95% CI 68% to 84%).  For a relative change in GLS, we observed a pooled sensitivity of 76% (95% CI 56% to 89%) and a pooled specificity of 83% (95% CI 73% to 90%).  For an absolute change in GLS, we observed a positive likelihood ratio (LR), and the negative LR was 4 and .21. Summary receiver operating characteristics curve with prediction and confidence intervals represents a promising summary area under the curve (sAUC) of .88, 95% CI ranges from .85 to .91 for absolute change in GLS, as well as for relative change (sAUC, .87, 95% CI .84 to .90).

CONCLUSION

Our results demonstrated an estimation of LV-GLS after the beginning of required chemotherapy, including anthracyclines and trastuzumab, had a promising prognostic value for predicting the likelihood of cancer therapeutics-related cardiac dysfunction. To confirm our findings, well-designed prospective adequately powered diagnostic randomised trials are necessary.

Andrographolide protects against doxorubicin-and arsenic trioxide-induced toxicity in cardiomyocytes

BACKGROUND

Andrographolide (AG) is a lactone diterpene with valuable biological activities. This in vitro study evaluated whether AG can protect cardiomyocytes under toxicities triggered with anti-cancer chemotherapeutic agents, doxorubicin (DOX) and arsenic trioxide (ATO).

METHODS AND RESULTS

H9C2 cells were pretreated with AG (0.5-10 µM) for 24 h and then exposed to DOX (1 μM) or ATO (35 μM) for another 24 h period. For determination of cell viability or cytotoxicity, MTT and lactate dehydrogenase (LDH) assay were used. Total oxidant and antioxidant capacities were estimated by determining hydroperoxides and ferric reducing antioxidant power (FRAP) levels. Real time-polymerase chain reaction was also used for quantitative evaluation of TLR4 gene expression. AG inhibited cardiomyocytes proliferation at the concentrations of more than 20 μM. However, it considerably enhanced cell viability and decreased cytotoxicity of DOX and ATO at the concentration range of 2.5-10 μM in MTT and LDH assays. AG significantly declined hydroperoxides concentration in ATO-treated cardiomyocytes and raised FRAP value in DOX- and ATO-treated cells. Furthermore, AG notably lessened TLR4 expression in H9C2 cells after exposure to DOX- and ATO.

CONCLUSION

In conclusion, these data presented that AG was able to reverse DOX- and ATO-induced cardiotoxicity in vitro. The cardiomyocyte protective activities of AG may be due to the decrease in TLR4 expression and total oxidant capacity and increase in total antioxidant capacity.

Long-Term Effects of Breast Cancer Therapy and Care: Calm after the Storm?

Breast cancer is still a lethal disease and the leading cause of death in women, undermining patients' survival and quality of life. Modern techniques of surgery and radiotherapy allow for the obtaining of good results in terms of survival, however they cause long-term side effects that persist over time, such as lymphedema and neuropathy. Similarly, the advent of new therapies such as endocrine therapy revolutionized breast cancer outcomes, but side effects are still present even in years of follow-up after cure. Besides the side effects of medical and surgical therapy, breast cancer is a real disruption in patients' lives considering quality of life-related aspects such as the distortion of body image, the psychological consequences of the diagnosis, and the impact on family dynamics. Therefore, the doctor-patient relationship is central to providing the best support both during treatment and afterwards. The aim of this review is to summarize the consequences of medical and surgical treatment on breast cancer patients and to emphasize the importance of early prevention of side effects to improve patients' quality of life.

Cardiotoxicity is mitigated after a supervised exercise program in HER2-positive breast cancer undergoing adjuvant trastuzumab

Background

Trastuzumab is used, alone or in conjunction with standard chemotherapy, to treat HER2-positive breast cancer (BC). Although it improves cancer outcomes, trastuzumab. can lead to cardiotoxicity. Physical exercise is a safe and effective supportive therapy in the management of side effects, but the cardioprotective effects of exercise are still unclear.

Objectives

The primary aim of this study was to test whether trastuzumab-induced cardiotoxicity [left ventricular ejection fraction (LVEF) under 50%, or an absolute drop in LVEF of 10%] was reduced after a supervised exercise program of 3 months in patients with HER2-positive breast cancer. Secondary endpoints were to evaluate (i) cardiotoxicity rates using other criteria, (ii) cardiac parameters, (iii) cardiorespiratory fitness and (iv) whether a change in LVEF influences the cardiorespiratory fitness.

Methods

89 women were randomized to receive adjuvant trastuzumab in combination with a training program (training group: TG; n = 46) or trastuzumab alone (control group: CG; n = 43). The primary and secondary endpoints were evaluated at the end of the supervised exercise program of 3 months (T3).

Results

After exercise program, 90.5 % of TG patients and 81.8% of CG patients did not exhibit cardiotoxicity. Furthermore, whatever the used criterion, percentage of patients without cardiotoxicity were greater in TG (97.6 and 100% respectively) than in CG (90.9 and 93.9% respectively). LVEF and GLS values remained stable in both groups without any difference between the groups. In contrast, at T3, peak VO2 (+2.6 mL.min−1.kg−1; 95%CI, 1.8 to 3.4) and maximal power (+21.3 W; 95%CI, 17.3 to 25.3) increased significantly in TG, whereas they were unchanged in CG (peak VO2: +0.2 mL.min−1.kg−1; 95%CI, −0.5 to 0.9 and maximal power: +0.7 W, 95%CI, −3.6 to 5.1) compared to values measured at T0. No correlation between LVEF changes and peak VO2 or maximal power was observed.

Conclusion

A 12-week supervised exercise regimen was safe and improved the cardiopulmonary fitness in particular peak VO2, in HER2-positive BC patients treated with adjuvant trastuzumab therapy. The study is under powered to come to any conclusion regarding the effect on cardiotoxicity.

Clinical trial registration

www.ClinicalTrials.gov, identifier: NCT02433067.

Cardiac safety analysis of first-line chemotherapy drug pegylated liposomal doxorubicin in ovarian cancer

Pegylated liposomal doxorubicin (PLD) is a nano-doxorubicin anticancer agent. It was used as early as 2014 to treat ovarian and breast cancer, multiple myeloma and Kaposi's sarcoma. The 2018 National Comprehensive Cancer Network guidelines listed PLD as first-line chemotherapy for ovarian cancer. PLD has significant anticancer efficacy and good tolerance. Although PLD significantly reduces the cardiotoxicity of conventional doxorubicin, its cumulative-dose cardiotoxicity remains a clinical concern. This study summarizes the high-risk factors for PLD-induced cardiotoxicity, clinical dose thresholds, and cardiac function testing modalities. For patients with advanced, refractory, and recurrent malignant tumors, the use of PLD is still one of the most effective strategies in the absence of evidence of high risk such as cardiac dysfunction, and the lifetime treatment dose should be unlimited. Of course, they should also be comprehensively evaluated in combination with the high-risk factors of the patients themselves and indicators of cardiac function. This review can help guide better clinical use of PLD.

Iron Overload and Breast Cancer: Iron Chelation as a Potential Therapeutic Approach

Breast cancer has historically been one of the leading causes of death for women worldwide. As of 2020, breast cancer was reported to have overtaken lung cancer as the most common type of cancer globally, representing an estimated 11.3% of all cancer diagnoses. A multidisciplinary approach is taken for the diagnosis and treatment of breast cancer that includes conventional and targeted treatments. However, current therapeutic approaches to treating breast cancer have limitations, necessitating the search for new treatment options. Cancer cells require adequate iron for their continuous and rapid proliferation. Excess iron saturates the iron-binding capacity of transferrin, resulting in non-transferrin-bound iron (NTBI) that can catalyze free-radical reactions and may lead to oxidant-mediated breast carcinogenesis. Moreover, excess iron and the disruption of iron metabolism by local estrogen in the breast leads to the generation of reactive oxygen species (ROS). Therefore, iron concentration reduction using an iron chelator can be a novel therapeutic strategy for countering breast cancer development and progression. This review focuses on the use of iron chelators to deplete iron levels in tumor cells, specifically in the breast, thereby preventing the generation of free radicals. The inhibition of DNA synthesis and promotion of cancer cell apoptosis are the targets of breast cancer treatment, which can be achieved by restricting the iron environment in the body. We hypothesize that the usage of iron chelators has the therapeutic potential to control intracellular iron levels and inhibit the breast tumor growth. In clinical settings, iron chelators can be used to reduce cancer cell growth and thus reduce the morbidity and mortality in breast cancer patients.

Breast cancer and incident cardiovascular events: A systematic analysis at the nationwide level

BACKGROUND

Breast cancer (BC) is one of the most common cancers worldwide, and the treatments are frequently cardiotoxic. Whether BC is associated with a higher risk of cardiovascular events is a matter of debate. We evaluated the associations among BC and incident cardiovascular events in a contemporary population.

METHODS

All female patients discharged from French hospitals in 2013 with at least 5 years of follow-up and without a history of major adverse cardiovascular event (myocardial infarction [MI], heart failure [HF], ischaemic stroke or all-cause death, and MACE-HF, which includes cardiovascular death, MI, ischaemic stroke or HF) or cancer (except BC) were identified. After propensity score matching, patients with BC were matched 1:1 with patients with no BC. Hazard ratios (HRs) for cardiovascular events during follow-up were adjusted on age, sex and smoking status at baseline.

RESULTS

1,795,759 patients were included, among whom 64,480 (4.3%) had history of BC. During a mean follow-up of 5.1 years, matched female patients with BC had a higher risk of all-cause death (HR 3.55, 95% confidence interval [CI]: 3.47-3.64), new-onset HF (HR 1.08, 95% CI 1.04-1.11), major bleeding (HR 1.43, 95% CI 1.36-1.49), MACE-HF (HR 1.07, 95% CI 1.04-1.11) and net adverse clinical events (NACE) including all-cause death, MI, ischaemic stroke, HF or major bleeding (HR 2.53, 95% CI 2.48-2.58) compared with those with no BC. By contrast, risks were not higher for cardiovascular death (HR 0.94, 95% CI 0.88-1.00) and were lower for MI (HR 0.81, 95% CI 0.75-0.88) and ischaemic stroke (HR 0.85, 95% CI 0.79-1.11).

CONCLUSIONS

In a large and contemporary analysis of female patients seen in French hospitals, women with history of breast cancer had a higher risk of all-cause mortality, new-onset heart failure and major bleeding compared to a matched cohort of women without breast cancer. In contrast, they have a reduced risk of cardiovascular mortality, MI and stroke.

Cardiotoxicity of Anticancer Drugs: Molecular Mechanisms and Strategies for Cardioprotection

Chemotherapy and targeted therapies have significantly improved the prognosis of oncology patients. However, these antineoplastic treatments may also induce adverse cardiovascular effects, which may lead to acute or delayed onset of cardiac dysfunction. These common cardiovascular complications, commonly referred to as cardiotoxicity, not only may require the modification, suspension, or withdrawal of life-saving antineoplastic therapies, with the risk of reducing their efficacy, but can also strongly impact the quality of life and overall survival, regardless of the oncological prognosis. The onset of cardiotoxicity may depend on the class, dose, route, and duration of administration of anticancer drugs, as well as on individual risk factors. Importantly, the cardiotoxic side effects may be reversible, if cardiac function is restored upon discontinuation of the therapy, or irreversible, characterized by injury and loss of cardiac muscle cells. Subclinical myocardial dysfunction induced by anticancer therapies may also subsequently evolve in symptomatic congestive heart failure. Hence, there is an urgent need for cardioprotective therapies to reduce the clinical and subclinical cardiotoxicity onset and progression and to limit the acute or chronic manifestation of cardiac damages. In this review, we summarize the knowledge regarding the cellular and molecular mechanisms contributing to the onset of cardiotoxicity associated with common classes of chemotherapy and targeted therapy drugs. Furthermore, we describe and discuss current and potential strategies to cope with the cardiotoxic side effects as well as cardioprotective preventive approaches that may be useful to flank anticancer therapies.

Risk of heart disease following treatment for breast cancer: results from a population-based cohort study

Background: There is a rising concern about treatment-associated cardiotoxicities in breast cancer patients. This study aimed to determine the time- and treatment-specific incidence of arrhythmia, heart failure and ischemic heart disease in women diagnosed with breast cancer.

Methods: A register-based matched cohort study was conducted including 8015 breast cancer patients diagnosed from 2001-2008 in the Stockholm-Gotland region and followed-up until 2017. Time-dependent risks of arrhythmia, heart failure and ischemic heart disease in breast cancer patients were assessed using flexible parametric models as compared to matched controls from general population. Treatment-specific effects were estimated in breast cancer patients using Cox model.

Results: Time-dependent analyses revealed long-term increased risks of arrhythmia and heart failure following breast cancer diagnosis. Hazard ratios (HRs) within the first year of diagnosis were 2.14 (95% CI = 1.63-2.81) for arrhythmia and 2.71 (95% CI = 1.70-4.33) for heart failure. HR more than 10 years following diagnosis was 1.42 (95% CI = 1.21-1.67) for arrhythmia and 1.28 (95% CI = 1.03-1.59) for heart failure. The risk for ischemic heart disease was significantly increased only during the first year after diagnosis (HR=1.45, 95% CI = 1.03-2.04). Trastuzumab and anthracyclines were associated with increased risk of heart failure. Aromatase inhibitors, but not tamoxifen, were associated with risk of ischemic heart disease. No increased risk of heart disease was identified following loco-regional radiotherapy.

Conclusions: Administration of systemic adjuvant therapies appears to be associated with increased risks of heart disease. The risk estimates observed in this study may aid adjuvant therapy decision-making and patient counseling in oncology practices.

Funding: This work was supported by the Swedish Research Council [grant no: 2018-02547]; Swedish Cancer Society [grant no: CAN-19-0266] and FORTE [grant no: 2016-00081].

Left breast radiotherapy - the impact of heart and lad doses to cardiovascular diseases developed eight years after treatment

Introduction/Objective. Left breast cancer patients undergoing radiotherapy are at higher risk of cardiovascular diseases (CVD), as a partial volume of the heart is anatomically close to target volume. This may cause cardiovascular diseases in the years following cancer treatment. The aim of this work was to develop a scoring system which identifies patients with increased risk of development of cardiovascular diseases, as consequence of left breast irradiation. Methods. The patients followed up in this study were treated during 2009. Eight years later, they were invited to participate in a study where they underwent a cardiology evaluation. Their current condition was statistically correlated to the doses received by their heart and left anterior descendant (LAD) artery. Results. Out of 114 patients, thirty-one women were evaluable for cardiology assessment. Out of these 31 subjects, six women were with a history of CVD before cancer treatment. Four women never developed any kind of heart associated disease, while in the other 27, newly onset CVD were diagnosed ranging from hypertension to myocardial infarction, strongly positively correlated to doses to heart and LAD (p = 0.003). Severity of developed cardiovascular toxicity was formulated through the correlation of mean heart and mean LAD doses with cardiovascular diseases developed in form of the scoring system. Conclusion. The doses to critical organs depend on patient anatomy and technique of irradiation. The cardiovascular complications are proven as consequence of radiotherapy. Scoring system based on doses received by heart and LAD is reliable tool in predicting CVD.

Cancer-A Major Cardiac Comorbidity With Implications on Cardiovascular Metabolism

Cardiovascular diseases have multifactorial causes. Classical cardiovascular risk factors, such as arterial hypertension, smoking, hyperlipidemia, and diabetes associate with the development of vascular stenoses and coronary heart disease. Further comorbidities and its impact on cardiovascular metabolism have gotten more attention recently. Thus, also cancer biology may affect the heart, apart from cardiotoxic side effects of chemotherapies. Cancer is a systemic disease which primarily leads to metabolic alterations within the tumor. An emerging number of preclinical and clinical studies focuses on the interaction between cancer and a maladaptive crosstalk to the heart. Cachexia and sarcopenia can have dramatic consequences for many organ functions, including cardiac wasting and heart failure. These complications significantly increase mortality and morbidity of heart failure and cancer patients. There are concurrent metabolic changes in fatty acid oxidation (FAO) and glucose utilization in heart failure as well as in cancer, involving central molecular regulators, such as PGC-1α. Further, specific inflammatory cytokines (IL-1β, IL-6, TNF-α, INF-β), non-inflammatory cytokines (myostatin, SerpinA3, Ataxin-10) and circulating metabolites (D2-HG) may mediate a direct and maladaptive crosstalk of both diseases. Additionally, cancer therapies, such as anthracyclines and angiogenesis inhibitors target common metabolic mechanisms in cardiomyocytes and malignant cells. This review focuses on cardiovascular, cancerous, and cancer therapy-associated alterations on the systemic and cardiac metabolic state.

Coronary artery calcifications on breast cancer radiotherapy planning CT scans and cardiovascular risk: What do patients want to know?

Background

Coronary artery calcifications (CAC) is a strong predictor of cardiovascular disease (CVD), which can be automatically quantified on routine breast radiotherapy planning computed tomography (CT) scans. Around 8% of patients have (very) high CAC scores and corresponding increased risks of CVD.

Aim

This study explores whether, how, and under what conditions women with breast cancer want to be informed about their CAC-based CVD risk.

Methods

A cross-sectional survey study was conducted in a random sample of UMBRELLA, a prospective breast cancer cohort. Participants (n = 79) filled out a questionnaire about their knowledge on the CVD risk following breast cancer, their interest in being informed about their CVD risk based on CAC score, and preferences on how they would want to receive this information.

Results

Most participants (66%) were not aware that the presence of CAC indicates an increased CVD risk. Participants indicated that they were not or only slightly aware of the risk of treatment-induced cardiotoxicity (48%), and that the risk of cardiotoxicity was higher in patients with pre-existing CVD risk factors (82%). The vast majority (90%) indicated that they want to be informed about in increased CAC-based CVD risk.

Conclusions

The majority of patients with breast cancer wants to be informed about their CAC-based CVD risk. With the majority of patients with breast cancer undergoing radiotherapy, and with low cost and automated options for accurate CAC measurement in planning CT scans, it is important to develop strategies to manage patients with an increased CAC-based risk of CVD.

Heart Failure in Breast Cancer Survivors: Focus on Early Detection and Novel Biomarkers

PURPOSE OF REVIEW

Breast cancer survival rate has greatly improved in the last two decades due to the emergence of next-generation anti-cancer agents. However, cardiotoxicity remains a significant adverse effect arising from traditional and emerging chemotherapies as well as targeted therapies for breast cancer patients. In this review, we will discuss cardiotoxicities of both traditional and emerging therapies for breast cancer. We will discuss current practices to detect cardiotoxicity of these therapies with the focus on new and emerging biomarkers. We will then focus on 'omics approaches, especially the use of epigenetics to discover novel biomarkers and therapeutics to mitigate cardiotoxicity.

RECENT FINDINGS

Significant cardiotoxicities of conventional chemotherapies remain and new and unpredictable new forms of cardiac and/or vascular toxicity emerge with the surge in novel and targeted therapies. Yet, there is no clear guidance on detection of cardiotoxicity, except for significant left ventricular systolic dysfunction, and even then, there is no uniform definition of what constitutes cardiotoxicity. The gold standard for detection of cardiotoxicity involves a serial echocardiography in conjunction with blood-based biomarkers to detect early subclinical cardiac dysfunction. However, the ability of these tests to detect early disease remains limited and not all forms of toxicity are detectable with these modalities. There is an unprecedented need to discover novel biomarkers that are sensitive and specific for early detection of subclinical cardiotoxicity. In that space, novel echocardiographic techniques, such as strain, are becoming more common-place and new biomarkers, discovered by epigenetic approaches, seem to become promising alternatives or adjuncts to conventional non-specific cardiac biomarkers.

Skeletal Muscle Deconditioning in Breast Cancer Patients Undergoing Chemotherapy: Current Knowledge and Insights From Other Cancers

Breast cancer represents the most commonly diagnosed cancer while neoadjuvant and adjuvant chemotherapies are extensively used in order to reduce tumor development and improve disease-free survival. However, chemotherapy also leads to severe off-target side-effects resulting, together with the tumor itself, in major skeletal muscle deconditioning. This review first focuses on recent advances in both macroscopic changes and cellular mechanisms implicated in skeletal muscle deconditioning of breast cancer patients, particularly as a consequence of the chemotherapy treatment. To date, only six clinical studies used muscle biopsies in breast cancer patients and highlighted several important aspects of muscle deconditioning such as a decrease in muscle fibers cross-sectional area, a dysregulation of protein turnover balance and mitochondrial alterations. However, in comparison with the knowledge accumulated through decades of intensive research with many different animal and human models of muscle atrophy, more studies are necessary to obtain a comprehensive understanding of the cellular processes implicated in breast cancer-mediated muscle deconditioning. This understanding is indeed essential to ultimately lead to the implementation of efficient preventive strategies such as exercise, nutrition or pharmacological treatments. We therefore also discuss potential mechanisms implicated in muscle deconditioning by drawing a parallel with other cancer cachexia models of muscle wasting, both at the pre-clinical and clinical levels.

Exercise effects on fatigue in breast cancer survivors after treatments: A systematic review and meta-analysis

AIM

The aim of this study is to explore the effects of exercise interventions by type, duration and intensity of exercise for fatigue in breast cancer survivors who had completed their treatment.

BACKGROUND

Most studies found that exercise has valuable outcomes for cancer survivors. This meta-analysis comprehensively summarizes the benefits of exercise intervention for fatigue in breast cancer patients who had completed their adjuvant treatments.

METHODS

We conducted a meta-analysis on randomized control trials published during 1 January 2000 through 31 December 2019, from PubMed, Cochrane Library databases, EMBASE, Medline (ProQuest), CINAHL, PsycINFO, Chinese Electronic Periodical Service and Wan Fan Data with prespecified searching criteria. Breast cancer patients earlier than stage IIIc and completing adjuvant treatments were included, and the effects of exercise on fatigue were investigated.

RESULTS

Nine randomized controlled trials (RCTs) were included (N = 581). Patients receiving exercise interventions showed reduced fatigue comparing with those without exercise. Exercise with low-moderate intensity, 20 min/day, three times per week and lasting up to 12 weeks had a significant effect on reducing fatigue for breast cancer survivors.

CONCLUSION

Our study suggested that exercise interventions can reduce fatigue for this group of cancer survivors. The duration and intensity of exercise intervention could be prescribed for this specific group of cancer patients as a basic requirement to handle their reported fatigue.

Assessment of toxicities and outcomes in patients with breast cancer treated with hypofractionated radiotherapy

Background

Hypofractionation is now becoming the standard of care in breast irradiation. The aim of this study was to assess the toxicities and outcomes in patients with breast cancer treated with hypofractionated radiotherapy (HFRT).

Methods

Patients with localized breast cancer who received adjuvant HFRT between 2013 and 2015 with a minimum follow-up of 6 months following radiation were included in this prospective study. Late toxicities were assessed using CTCAE v 4 and included chest/breast pain, limb pain, limb edema, skin pigmentation, skin fibrosis, and shoulder movement restriction. Outcomes assessed included locoregional control, disease-free survival, and overall survival. Statistical analysis was done using Microsoft Excel and SPSS v22.

Results

A total of 81 patients fulfilled the inclusion criteria, of which 19 patients had died during follow-up. Regional nodal irradiation was done in 63 (77.8%) patients using the same hypofractionated schedule of 40 Gy in 15 fractions. Late toxicities were assessed for 62 patients. The median follow-up following the course of hypofractionated radiation was 45 months (range 14 - 65 months). Late toxicities were assessed for 62 patients. Grade 1/2 chest/breast pain, limb pain, limb edema, skin pigmentation, skin fibrosis, and shoulder movement restriction were seen in 11%, 12%, 7%, 6%, 8%, and 11% of cases, respectively. Distant recurrences were seen in 8% of cases, and there were no locoregional recurrences. Five-year overall survival was 76.5%.

Conclusion

HFRT to whole breast or chest wall and the regional nodal areas was well-tolerated with acceptable rates of late toxicities on follow-up.

Prevention of Cardiac Dysfunction During Adjuvant Breast Cancer Therapy (PRADA): Extended Follow-Up of a 2×2 Factorial, Randomized, Placebo-Controlled, Double-Blind Clinical Trial of Candesartan and Metoprolol

BACKGROUND

Adjuvant breast cancer therapy containing anthracyclines with or without anti-human epidermal growth factor receptor-2 antibodies and radiotherapy is associated with cancer treatment-related cardiac dysfunction. In the PRADA trial (Prevention of Cardiac Dysfunction During Adjuvant Breast Cancer Therapy), concomitant treatment with the angiotensin receptor blocker candesartan attenuated the reduction in left ventricular ejection fraction (LVEF) in women receiving treatment for breast cancer, whereas the β-blocker metoprolol attenuated the increase in cardiac troponins. This study aimed to assess the long-term effects of candesartan and metoprolol or their combination to prevent a reduction in cardiac function and myocardial injury.

METHODS

In this 2×2 factorial, randomized, placebo-controlled, double-blind, single-center trial, patients with early breast cancer were assigned to concomitant treatment with candesartan cilexetil, metoprolol succinate, or matching placebos. Target doses were 32 and 100 mg, respectively. Study drugs were discontinued after adjuvant therapy. All 120 validly randomized patients were included in the intention-to-treat analysis. The primary outcome measure was change in LVEF assessed by cardiovascular magnetic resonance imaging from baseline to extended follow-up. Secondary outcome measures included changes in left ventricular volumes, echocardiographic peak global longitudinal strain, and circulating cardiac troponin concentrations.

RESULTS

A small decline in LVEF but no significant between-group differences were observed from baseline to extended follow-up, at a median of 23 months (interquartile range, 21 to 28 months) after randomization (candesartan, 1.7% [95% CI, 0.5 to 2.8]; no candesartan, 1.8% [95% CI, 0.6 to 3.0]; metoprolol, 1.6% [95% CI, 0.4 to 2.7]; no metoprolol, 1.9% [95% CI, 0.7 to 3.0]). Candesartan treatment during adjuvant therapy was associated with a significant reduction in left ventricular end-diastolic volume compared with the noncandesartan group (P=0.021) and attenuated decline in global longitudinal strain (P=0.046) at 2 years. No between-group differences in change in cardiac troponin I and T concentrations were observed.

CONCLUSIONS

Anthracycline-containing adjuvant therapy for early breast cancer was associated with a decline in LVEF during extended follow-up. Candesartan during adjuvant therapy did not prevent reduction in LVEF at 2 years, but was associated with modest reduction in left ventricular end-diastolic volume and preserved global longitudinal strain. These results suggest that a broadly administered cardioprotective approach may not be required in most patients with early breast cancer without preexisting cardiovascular disease. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01434134.

Breast Radiotherapy-Related Cardiotoxicity. When, How, Why. Risk Prevention and Control Strategies

In recent decades, improvements in breast cancer management have increased overall patient survival; however, many cancer therapies have been linked to an important risk of cardiovascular adverse events. Cardio-oncology has been proposed as an emerging specialty to coordinate preventive strategies that improve the cardiovascular health of oncologic patients. It employs the most suitable personalized multidisciplinary management approach for each patient to optimize their cardiovascular health and improve their survival and quality of life. Radiotherapy is an essential part of the therapeutic regimen in breast cancer patients but can also increase the risk of cardiovascular disease. Therefore, minimizing the negative impact of radiation therapy is an important challenge for radiotherapy oncologists and cardiologists specializing in this field. The aim of the present review is to update our knowledge about radiation-induced cardiotoxicity in breast cancer patients by undertaking a critical review of the relevant literature to determine risk prevention and control strategies currently available.

How can we manage the cardiac toxicity of immune checkpoint inhibitors?

Introduction: Cancer immunotherapies with monoclonal antibodies (mAbs) against immune checkpoints (i.e. CTLA-4 and PD-1/PD-L1) have revolutionized antineoplastic treatments. Immune checkpoint inhibitors (ICIs) approved for cancer immunotherapy are mAbs anti-CTLA-4 (ipilimumab), anti-PD-1 (nivolumab, pembrolizumab, and cemiplimab), and anti-PD-L1 (atezolizumab, avelumab, and durvalumab). Treatment with ICIs can be associated with immune-related adverse events (irAEs), including an increased risk of developing myocarditis. These findings are compatible with the observation that, CTLA-4, PD-1, and PD-L1 pathways play a central role in the modulation of autoimmunity.Areas covered: In this paper, we start from examining the pathogenesis of cardiovascular adverse events from ICIs, and then we focus on risk factors and strategies to prevent and manage this cardiotoxicity.Expert opinion: There is a growing need for a multidisciplinary approach of ICI-associated cardiotoxicity, involving oncologists, cardiologists, and immunologists. Prevention and effective management of ICIs cardiotoxicity starts with an in-depth screening and surveillance strategies of high-risk patients, in order to improve early detection and appropriate management in a personalized approach.

Targeting transcription of MCL-1 sensitizes HER2-amplified breast cancers to HER2 inhibitors

Human epidermal growth factor receptor 2 gene (HER2) is focally amplified in approximately 20% of breast cancers. HER2 inhibitors alone are not effective, and sensitizing agents will be necessary to move away from a reliance on heavily toxic chemotherapeutics. We recently demonstrated that the efficacy of HER2 inhibitors is mitigated by uniformly low levels of the myeloid cell leukemia 1 (MCL-1) endogenous inhibitor, NOXA. Emerging clinical data have demonstrated that clinically advanced cyclin-dependent kinase (CDK) inhibitors are effective MCL-1 inhibitors in patients, and, importantly, well tolerated. We, therefore, tested whether the CDK inhibitor, dinaciclib, could block MCL-1 in preclinical HER2-amplified breast cancer models and therefore sensitize these cancers to dual HER2/EGFR inhibitors neratinib and lapatinib, as well as to the novel selective HER2 inhibitor tucatinib. Indeed, we found dinaciclib suppresses MCL-1 RNA and is highly effective at sensitizing HER2 inhibitors both in vitro and in vivo. This combination was tolerable in vivo. Mechanistically, liberating the effector BCL-2 protein, BAK, from MCL-1 results in robust apoptosis. Thus, clinically advanced CDK inhibitors may effectively combine with HER2 inhibitors and present a chemotherapy-free therapeutic strategy in HER2-amplified breast cancer, which can be tested immediately in the clinic.

Exploring the Potential Role of the Gut Microbiome in Chemotherapy-Induced Neurocognitive Disorders and Cardiovascular Toxicity

Simple Summary

While lifesaving achievements have allowed cancer to be cured in many patients, survivors cured of cancer may suffer from long-term adverse treatment sequelae, substantially altering their quality of life and reintegration into normal life. Increasing evidence suggests the emerging role of the microbiome in chemotherapy-induced late effects affecting cognitive functions and the cardiovascular system. Moreover, existing data from animal models and patients with neurocognitive disorders and cardiovascular diseases outline the possibility that microbiota modulation might potentially prevent or mitigate the psycho-physiological deficits following chemotherapy and help to improve the behavioral comorbidities, cognitive functions, and quality of life in cancer survivors.

Abstract

Chemotherapy, targeting not only malignant but also healthy cells, causes many undesirable side effects in cancer patients. Due to this fact, long-term cancer survivors often suffer from late effects, including cognitive impairment and cardiovascular toxicity. Chemotherapy damages the intestinal mucosa and heavily disrupts the gut ecosystem, leading to gastrointestinal toxicity. Animal models and clinical studies have revealed the associations between intestinal dysbiosis and depression, anxiety, pain, impaired cognitive functions, and cardiovascular diseases. Recently, a possible link between chemotherapy-induced gut microbiota disruption and late effects in cancer survivors has been proposed. In this review, we summarize the current understanding of preclinical and clinical findings regarding the emerging role of the microbiome and the microbiota–gut–brain axis in chemotherapy-related late effects affecting the central nervous system (CNS) and heart functions. Importantly, we provide an overview of clinical trials evaluating the relationship between the gut microbiome and cancer survivorship. Moreover, the beneficial effects of probiotics in experimental models and non-cancer patients with neurocognitive disorders and cardiovascular diseases as well as several studies on microbiota modulations via probiotics or fecal microbiota transplantation in cancer patients are discussed.

Stratification of Estrogen Receptor-Negative Breast Cancer Patients by Integrating the Somatic Mutations and Transcriptomic Data

Patients with estrogen receptor-negative breast cancer generally have a worse prognosis than estrogen receptor-positive patients. Nevertheless, a significant proportion of the estrogen receptor-negative cases have favorable outcomes. Identifying patients with a good prognosis, however, remains difficult, as recent studies are quite limited. The identification of molecular biomarkers is needed to better stratify patients. The significantly mutated genes may be potentially used as biomarkers to identify the subtype and to predict outcomes. To identify the biomarkers of receptor-negative breast cancer among the significantly mutated genes, we developed a workflow to screen significantly mutated genes associated with the estrogen receptor in breast cancer by a gene coexpression module. The similarity matrix was calculated with distance correlation to obtain gene modules through a weighted gene coexpression network analysis. The modules highly associated with the estrogen receptor, called important modules, were enriched for breast cancer-related pathways or disease. To screen significantly mutated genes, a new gene list was obtained through the overlap of the important module genes and the significantly mutated genes. The genes on this list can be used as biomarkers to predict survival of estrogen receptor-negative breast cancer patients. Furthermore, we selected six hub significantly mutated genes in the gene list which were also able to separate these patients. Our method provides a new and alternative method for integrating somatic gene mutations and expression data for patient stratification of estrogen receptor-negative breast cancers.

Patterns of chronic disease management and health outcomes in a population-based cohort of Black women with breast cancer

PURPOSE

Diabetes and hypertension are two common comorbidities that affect breast cancer patients, particularly Black women. Disruption of chronic disease management during cancer treatment has been speculated. Therefore, this study examined the implementation of clinical practice guidelines and health outcomes for these comorbidities before and during cancer treatment.

METHODS

We used a population-based, prospective cohort of Black women diagnosed with breast cancer (2012-2016) in New Jersey (n = 563). Chronic disease management for diabetes and hypertension was examined 12 months before and after breast cancer diagnosis and compared using McNemar's test for matched paired and paired t tests.

RESULTS

Among this cohort, 18.1% had a co-diagnosis of diabetes and 47.2% had a co-diagnosis of hypertension. Implementation of clinical practice guidelines and health outcomes that differed in the 12 months before and after cancer diagnosis included lipid screening (64.5% before versus 50.0% after diagnosis; p = 0.004), glucose screening (72.7% versus 90.7%; p < 0.001), and blood pressure control < 140/90 mmHg (57.6% versus 71.5%; p = 0.004) among patients with hypertension-only. For patients with diabetes, eye and foot care were low (< 35%) and optimal HbA1c < 8.0% was achieved for less than 50% of patients in both time periods.

CONCLUSION

Chronic disease management continued during cancer treatment; however, eye and foot exams for patients with diabetes and lipid screening for patients with hypertension-only were inadequate. Given that comorbidities may account for half of the Black-White breast cancer survival disparity, strategies are needed to improve chronic disease management during cancer, especially for Black women who bear a disproportionate burden of chronic diseases.

Cardiovascular Disease Amongst Women Treated for Breast Cancer: Traditional Cytotoxic Chemotherapy, Targeted Therapy, and Radiation Therapy

PURPOSE OF REVIEW

Cardiotoxicity can occur acutely during breast cancer treatment and impact the potential for the intended cancer treatment regime to be completed, or as a late effect affecting cancer survivorship. Indeed, the most common cause of mortality in females with early breast cancer is cardiovascular disease, especially in those over the age of 65. Optimal cancer care therefore needs to be delivered without jeopardising cardiovascular health. Understanding the different cardiotoxicities associated with breast cancer treatment is vital to this approach, and therefore, this article seeks to provide an overview of this.

RECENT FINDINGS

Tyrosine kinase inhibitors targeting human epidermal growth factor receptor (HER)-2, immune checkpoint inhibitors (ICI), and cyclin-dependent kinase (CDK) inhibitors are new targeted breast cancer treatments. In particular, ICI are associated with myocarditis that carries a significant mortality, whilst the CDK inhibitor ribociclib causes QT prolongation that requires cardiac surveillance and appropriate dose adjustment to prevent ventricular arrhythmias. The need has always been for strategies to mitigate the risks of cardiovascular toxicities, and new data is promising for the use of dexrazoxane in anthracyclines, and the role of beta blockers and angiotensin converting enzymes inhibitors in anthracyclines and HER-2 monoclonal antibodies such as trastuzumab. Significant headways in breast cancer treatment have resulted in reductions in disease recurrence and mortality, but cardiovascular complications continue to impact the ability to deliver some of these cancer treatments, and the period of cancer survivorship.

Higher efficacy and reduced adverse reactions in neoadjuvant chemotherapy for breast cancer by using pegylated liposomal doxorubicin compared with pirarubicin

The present study aimed to investigate the efficacy and toxicity of pegylated liposomal doxorubicin (PLD) in preoperative neoadjuvant chemotherapy for patients with breast cancer by comparing with conventional anthracycline. This study is a non-randomized controlled trial. Prospective analysis was conducted after matching as required. A total of 146 patients with confirmed diagnosis of breast cancer by histopathological examinations were enrolled into the observation group and control group in 1:1 ratio. Each of the cases in the observation group was required to correspond to another in the control group according to the requirements including age, molecular subtype, axillary node status, and regimen of the preoperative neoadjuvant chemotherapy. The chemotherapy was based on regimens consisting of anthracyclines, paclitaxel or docetaxel, and/or platinum. PLD was used at least twice in the observation group, with traditional anthracycline as a contrast in the control group. Clinical responses as well as cardiac side effects and other adverse reactions were evaluated by clinical and imaging examinations such as electrocardiogram (ECG) and color Doppler ultrasound during the chemotherapy. Pathologic examinations were performed following the surgeries after preoperative neoadjuvant chemotherapy. All the patients in both groups completed the preoperative neoadjuvant chemotherapy according to their original regimens. The postoperative pathological evaluation revealed a higher pathologic complete response (PCR) rate and significantly more patients of grade V of the Miller-Payne grading system in the observation group as compared to the control group (p = 0.047). In addition, the observation group recorded an evidently lower occurrence of the adverse cardiac events (p = 0.014), ECG changes (p = 0.048), and the relatively severe adverse reactions such as myelosuppression. Compared with conventional anthracycline drugs, PLD has a better pathologic response and safety performance, as well as a similar clinical effectiveness in preoperative neoadjuvant chemotherapy for breast cancer.

Postdiagnostic Dietary Glycemic Index, Glycemic Load, Dietary Insulin Index, and Insulin Load and Breast Cancer Survival

BACKGROUND

We investigated the associations of postdiagnostic dietary glycemic index (GI), glycemic load (GL), insulin index (II), and insulin load (IL) with breast cancer-specific and all-cause mortality.

METHODS

Among 8,932 women with stage I-III breast cancer identified in the Nurses' Health Study (NHS; 1980-2010) and NHSII (1991-2011), we prospectively evaluated the associations between postdiagnostic GI, GL, II, and IL, and breast cancer-specific and all-cause mortality. Participants completed a validated food frequency questionnaire every 4 years after diagnosis.

RESULTS

During follow-up by 2014 in the NHS and 2015 in the NHSII, 2,523 deaths, including 1,071 from breast cancer, were documented. Higher postdiagnostic GL was associated with higher risk of both breast cancer-specific mortality [HR_Q5vsQ1 = 1.33; 95% confidence interval (CI) = 1.09-1.63; P _trend = 0.008] and all-cause mortality (HR_Q5vsQ1 = 1.26; 95% CI = 1.10-1.45; P _trend = 0.0006). Higher all-cause mortality was also observed with higher postdiagnostic GI (HR_Q5vsQ1 = 1.23; 95% CI = 1.08-1.40; P _trend = 0.001), II (HR_Q5vsQ1 = 1.20; 95% CI = 1.04-1.38; P _trend = 0.005), and IL (HR_Q5vsQ1 = 1.23; 95% CI = 1.07-1.42; P _trend = 0.0003). The associations were not modified by insulin receptor or estrogen receptor status of the tumor, or body mass index.

CONCLUSIONS

We found that higher dietary GL, reflecting postprandial glucose response, after a breast cancer diagnosis was associated with higher risk of breast cancer-specific mortality. Higher dietary GI, GL, II, and IL after a breast cancer diagnosis were associated with higher risk of death from any cause.

IMPACT

These results suggest that carbohydrate quantity and quality may be important in breast cancer prognosis.See related commentary by McTiernan, p. 252.

Predictors of new-onset heart failure and overall survival in metastatic breast cancer patients treated with liposomal doxorubicin

Cardiovascular diseases (CVDs) are the major cause of morbidity/mortality among breast cancer (BC) patients. Observation of the daily practice in eight experienced Polish oncology centers was conducted to find all possible predictors of new cases of heart failure (HF) and overall survival (OS) of metastatic BC patients treated with liposomal doxorubicin, taking into account the impact of pre-existing CVDs. HF was the cause of premature discontinuation of liposomal doxorubicin therapy in 13 (3.2%) of 402 patients. The probability of developing HF was higher in women with pre-existing CVDs (HR 4.61; 95%CI 1.38–15.38). Independent of CVDs history, a lower risk of HF was observed in those treated with a cumulative dose of liposomal doxorubicin > 300 mg/m2 (HR 0.14; 95% CI 0.04–0.54) and taxane-naive (HR 0.26; 95% CI 0.07–0.96). Multivariate analysis including the presence of pre-existing CVDs and occurrence of new HF, revealed a liposomal doxorubicin in cumulative doses of > 300 mg/m2 as a beneficial predictor for OS (HR 0.61; 95% CI 0.47–0.78) independently of subsequent chemotherapy (HR 0.72; 95% CI 0.57–0.92) or endocrine therapy (HR 0.65; 95% CI 0.49–0.87). Higher doses of liposomal doxorubicin can decrease mortality in metastatic BC without increasing the risk of HF. The clinical benefit is achieved regardless of pre-existing CVDs and subsequent anticancer therapy.

Evaluation of analytical accuracy of HER2 status in patients with breast cancer: Comparison of HER2 GPA with HER2 IHC and HER2 FISH

Human epidermal growth factor receptor 2 (HER2) gene status and overexpression, occurring in ~ 13.6% of primary breast cancers, is essential for identifying patients likely to benefit from biological treatment. In this method of evaluation study, we tested and compared the HER2 gene-protein assay (GPA) with routine HER2 immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). The GPA was evaluated using 67 formalin-fixed paraffin-embedded (FFPE) HER2 equivoval IHC (2+) breast cancer tissue samples. Overall, agreement between GPA silver in situ hybridization (SISH) and FISH was 91.9% (57/62). Regression analysis revealed slightly higher, but non-significant difference in HER2/chromosome enumeration probe 17 (CEP17) ratio for GPA as compared to FISH (p = 0.074). Intraclass correlation coefficients (ICCs) of 0.94 and Spearman´s rank correlation coefficients of 0.93 (p < 0.0001) for FISH and GPA SISH suggested strong inter-observer association for methods with one observer counting on average 0.23 significant higher for GPA SISH (p = 0.014). Intra-observer IHC method reproducibility was 52.6% (κ = 0.3122, p = 0.004) and 79.7% (κ = 0.6428, p = 0.9197), suggesting fair significant and substantial non-significant difference between tests for reviewers. Inter-observer reproducibility for IHC methods was 53%. While inter-observer reproducibility for experienced IHC interpretation suggested significant differences (κ = 0.3636, p = 0.0332), unexperienced interpretation of IHC GPA suggested fair non-significant difference between reviewers (κ = 0.3101, p = 0.0747). Using FISH as reference, the diagnostic indices for GPA SISH were as follows: sensitivity 100%, specificity 95% and accuracy 92%. Inaccuracy between tests was in 80% of cases due to ISH categorization as equivocal by one of the methods. IHC results highlight that it may be beneficial with a method for simultaneously visualization of HER2 gene and protein status.

Exercise training affects hemodynamics not cardiac function during anthracycline-based chemotherapy

INTRODUCTION

Preclinical data demonstrate the potential for exercise training to protect against anthracycline-related cardiotoxicity, but this remains to be shown in humans.

PURPOSE

To assess whether exercise training during anthracycline-based chemotherapy for treatment of breast cancer affects resting cardiac function and hemodynamics.

METHODS

In this prospective, non-randomized controlled study, 26 women who participated in aerobic and resistance training 3×/wk during chemotherapy were compared to 11 women receiving usual care. Two-dimensional echocardiography was performed before and 7-14 days after completion of anthracycline-based chemotherapy. Pre- and post-anthracycline cardiac function and hemodynamic variables were compared within each group with paired t-tests; the change was compared between groups using ANCOVA with adjustment for baseline values.

RESULTS

Left ventricular longitudinal strain, volumes, ejection fraction, E/A ratio, and mass did not change in either group. Hemoglobin, hematocrit, and mean arterial pressure decreased significantly from baseline in both groups (all p < 0.05) with no differences between groups. Cardiac output increased in the usual care group only (+ 0.27 ± 0.24 L/min/m², p < 0.01), which differed significantly from the exercise group (p = 0.03). Systemic vascular resistance (SVR) decreased in both groups (usual care: - 444, p < 0.01; exercise: - 265, dynes/s/cm⁵, p = 0.01). However, the reduction in SVR was significantly attenuated in the exercise group (p = 0.03) perhaps due to a compensatory decrease in estimated vessel lumen radius.

CONCLUSION

Exercise training during anthracycline chemotherapy treatment had no effect on resting cardiac function but appeared to modify hemodynamic responses. Specifically, exercise training attenuated the drop in SVR in response to chemotherapy-related reductions in hematocrit potentially by increasing vessel lumen radius.

Effects of tamoxifen and aromatase inhibitors on the risk of acute coronary syndrome in elderly breast cancer patients: An analysis of nationwide data

Background

Aromatase inhibitors (AIs) are the preferred endocrine treatment for postmenopausal hormonal receptor-positive breast cancer. However, there is controversy on the long-term cardiovascular and cerebrovascular safety of AIs over that of tamoxifen.

Methods

We analyzed the National Health Information Database (NHID) of 281,255 women over a 20-year-old diagnosed with breast cancer between 2009 and 2016. Cardiovascular events (CVEs) were defined as the development of the following, acute coronary syndrome (ACS), ischemic and hemorrhagic stroke, defined by using insurance claim records. The model was constructed by Cox proportional hazard regression and this model was used to analyze the effects of AI and tamoxifen on CVE.

Results

We included 47,569 women for the final analysis. Patients were classified into ‘No hormonal treatment (n = 18,807), ‘Switch (n = 2097)’, ‘Tamoxifen (n = 7081)’ and ‘AI (n = 19,584)’. There were 2147 CVEs in 2032 patients (4.1%). Univariate analysis showed that women with tamoxifen had significantly lower risk for CVEs compared to no-treatment (hazard ratio (HR) 0.84, 95% confidence interval (CI) 0.74–0.97) while AI showed no such effect (HR 0.93, 95% CI 0.84–1.02). After adjusting for other risk factors (hypertension, dyslipidemia, family history), the use of tamoxifen was associated with significant protective effect against ACS (HR 0.63, 95% CI 0.47–0.84).

Conclusions

Our results, based on the NHID, supports the protective effect of tamoxifen against CVE in Korean breast cancer patients aged 55 and older that is not seen with AIs. Our results can guide the selection of adjuvant hormonal treatment agents for Korean breast cancer patients based on their risk of developing CVE.

•

Controversy on the long-term cardiovascular and cerebrovascular safety of AIs over that of tamoxifen.

•

The protective effect of tamoxifen against cardiovascular events in elderly breast cancer patients that is not seen with AIs.

•

Choice of hormonal therapy depends on patient’s cardiovascular or cerebrovascular risks.

Cytotoxic-induced heart failure among breast cancer patients in Nigeria: A call to prevent today's cancer patients from being tomorrow's cardiac patients

We report three cases of heart failure (HF) associated with the use of cytotoxic drugs such as anthracycline, cyclophosphamide, and 5-fluorouracil in the treatment of breast cancer in Nigerians. The patients had systolic and diastolic HF: HF with reduced ejection fraction and preserved ejection fraction. The prevalence of breast cancer is increasing across Africa, and cytotoxics are some of the most common and best drugs used during management. The cardiotoxicity caused by these drugs limits their use as chemotherapeutic agents. Cytotoxic-induced HF is a preventable and manageable cause of cardiovascular disease (CVD) in Nigeria and Africa. This article discusses the pathophysiology of cytotoxic-induced HF and presents the risk factors that impair cardiovascular function. The importance of proper assessment and the prophylactic and therapeutic measures in the management of cytotoxic-induced HF are emphasized. The peculiar challenges in the management of cytotoxic-induced HF in Nigeria were also discussed. The need for early involvement of cardiologists by oncologists to improve on the chemotherapeutic and cardiovascular outcome in the management of patients with breast cancer was stressed. Perhaps, it is time to birth a new discipline of cardiooncology in Nigeria.

Pivarubicin Is More Effective Than Doxorubicin Against Triple-Negative Breast Cancer In Vivo

Triple-negative breast cancer (TNBC) is unresponsive to antiestrogen and anti-HER2 therapies, requiring the use of cytotoxic drug combinations of anthracyclines, taxanes, cyclophosphamide, and platinum compounds. Multidrug therapies achieve pathological cure rates of only 20–40%, a consequence of drug resistance and cumulative dose limitations necessitated by the reversible cardiotoxic effects of drug therapy. Safer and more effective treatments for TNBC are required to achieve durable therapeutic responses. This study describes the mechanistic analyses of the novel anthracycline, pivarubicin, and its in vivo efficacy against human primary TNBC. Pivarubicin directly activates PKCd, triggers rapid mitochondrial-dependent apoptosis, and circumvents resistance conferred by overexpression of P-glycoprotein, Bcl-2, Bcl-X_L, and Bcr-Abl. As a consequence, pivarubicin is more cytotoxic than doxorubicin against MDA-MB-231, and SUM159 TNBC cell lines grown in both monolayer culture and tumorspheres. Comparative in vivo efficacy of pivarubicin and doxorubicin was performed in an orthotopic NSG mouse model implanted with MDA-MB-231 human TNBC cells and treated with the maximum tolerated doses (MTDs) of pivarubicin and doxorubicin. Tumor growth was monitored by digital caliper measurements and determination of endpoint tumor weight and volume. Endpoint cardiotoxicity was assessed histologically by identifying microvacuolization in ventricular cardiomyocytes. Primary tumors treated with multiple rounds of doxorubicin at MTD failed to inhibit tumor growth compared with vehicle-treated tumors. However, administration of a single MTD of pivarubicin produced significant inhibition of tumor growth and tumor regression relative to tumor volume prior to initiation of treatment. Histological analysis of hearts excised from drug- and vehicle-treated mice revealed that pivarubicin produced no evidence of myocardial damage at a therapeutic dose. These results support the development of pivarubicin as a safer and more effective replacement for doxorubicin against TNBC as well as other malignancies for which doxorubicin therapy is indicated.

Research progress of biomarkers in early detection of chemotherapy-induced cardiotoxicity

With the advances of drug therapy, the prognosis of cancer patients has seen remarkable improvements, and cancer-related mortality has decreased significantly. However, the followed drug-related cardiotoxicity becomes a serious threat to patients' living quality and survival rate. Cardiovascular toxicity associated with some chemotherapy drugs is reversible and dose-dependent. If early identification is possible, early cardiovascular protection measures or adjustment of chemotherapy regimens can be taken to improve the prognosis of patients. Therefore, early prevention and monitoring of chemotherapy-related cardiotoxicity are critical for cancer patients and survivors. Among them, biomarkers are an important method for the early identification of myocardial injury.

Effects of Weight Loss and Weight Regain on Circulating Biomarkers in Overweight/Obese Breast Cancer Survivors Enrolled in a Weight Loss Trial in the Rural Midwest

BACKGROUND

Obesity is associated with worse breast cancer prognosis, however little is known about the level of weight loss required to improve pathway biomarkers. The effects of weight regain on biomarkers are also largely unknown.

METHODS

Overweight/obese breast cancer survivors enrolled in an 18-month behavioral weight loss trial provided weight and serum biomarkers [leptin, adiponectin, insulin, plasminogen activator inhibitor-1 (PAI-1), IL-6, TNFα, and hepatocyte growth factor HGF] at baseline, 6, and 18 months (n = 138). Change in biomarkers over time and by weight loss thresholds were examined.

RESULTS

Mean weight loss at 6 months was 13.3 ± 5.0 kg; from 6 to 18 months, mean regain was 4.0 ± 5.2 kg. Favorable biomarker modulations were observed at 6 months for leptin, adiponectin, insulin, PAI-1, IL-6, and HGF (P < 0.006 to P < 0.0001). These changes remained significant overall at 18 months despite attenuation in some. Women who lost <10% of baseline weight showed significantly smaller modulation effects for leptin (P < 0.0001), adiponectin:leptin (A/L) ratio (P < 0.0001), PAI-1 (P < 0.001), and insulin (P = 0.003) compared with women who lost >10%. Women who lost >10% observed a significant increase in adiponectin (P < 0.0001), and these women continued to show improved adiponectin from 6 to 18 months despite weight regain. Physical activity contributed additional effects on biomarker change for leptin, A/L ratio, and PAI-1.

CONCLUSIONS

These findings are consistent with a clinical target of 10% weight.

IMPACT

Sustained increases in adiponectin likely confer benefits for breast cancer prognosis even with weight regain.

Outcome and presentation of heart failure in breast cancer patients: findings from a Swedish register-based study

AIMS

Heart failure (HF) patients diagnosed with breast cancer (BC) may have a higher risk of death, and different HF presentation and treatment than patients without BC.

METHODS AND RESULTS

A total of 14 998 women with incident HF (iHF) or prevalent HF (pHF) enrolled in the Swedish HF Registry within and after 1 month since HF diagnosis, respectively, between 2008 and 2013. Patients were linked with the National Patient-, Cancer-, and Cause-of-Death Registry. Two hundred and ninety-four iHF and 338 pHF patients with BC were age-matched to 1470 iHF and 1690 pHF patients without BC. Comorbidity and treatment characteristics were compared using the χ2 tests for categories. Cox proportional hazard models assessed the hazard ratio (HR) and 95% confidence intervals (95% CIs) of all-cause and cardiovascular mortality among HF patients with and without BC. In the pHF group, BC patients had less often myocardial infarction (21.6% vs. 28.6%, P < 0.01) and received less often aspirin (47.6% vs. 55.1%, P = 0.01), coronary revascularization (11.8% vs. 16.2%, P < 0.01), or device therapy (0.9% vs. 3.0%, P = 0.03). After median follow-up of 2 years, risk of all-cause mortality (iHF: HR = 1.04, 95% CI = 0.83-1.29 and pHF: HR = 0.94, 95% CI = 0.79-1.12), cardiovascular mortality (iHF: HR = 0.94, 95% CI = 0.71-1.24 and pHF: HR = 0.89, 95% CI = 0.71-1.10), and HF mortality (iHF: HR = 0.80, 95% CI = 0.34-1.90 and pHF: HR = 0.75, 95% CI = 0.43-1.29) were similar for patients with and without BC in the iHF and pHF groups.

CONCLUSION

Risk of all-cause and cardiovascular mortality in HF patients did not differ by BC status. Differences in pre-existing myocardial infarction and HF treatment among pHF patients with and without BC may suggest differences in pathogenesis of HF.

The long-term effect of age on cardiovascular disease in patients with breast cancer who received chemotherapy

PURPOSE

As breast cancer survival has significantly improved and patient life expectancy has increased, greater numbers of elderly breast cancer survivors are at risk for cardiovascular disease (CVD). Therefore, this study investigated the impact of age on the incidence, mortality, and predictors of CVD following adjuvant chemotherapy in the late period of survivorship.

METHODS

761 Patients who underwent chemotherapy were enrolled and divided into patients aged < 50 years (n = 413, 54.3%) and patients aged ≥ 50 years (n = 348, 45.7%). Among the entire cohort, 445 patients underwent transthoracic echocardiography.

RESULTS

During long-term follow-up (median 122 months, range 12-340 months), CVD events developed in 50 (6.57%) patients, including 17 (4.1%) aged < 50 years and 33 (9.5%) aged ≥ 50 years (p = 0.003). 8 (1.1%) of 50 patients with CVD died, including 1 patient aged < 50 years and 7 patients aged ≥ 50 years. CVD-free survival was significantly lower in patients aged ≥ 50 years compared with patients aged < 50 years (p < 0.001). In multivariate analyses, age ≥ 50 years [p < 0.001, hazard ratio (HR) = 3.802, 95% confidence interval (CI) 1.986-7.278], the radio of the peak early and mitral tissue Doppler velocities (p = 0.014, HR = 1.102, 95% CI 1.020-1.190), and global longitudinal strain (p < 0.001, HR = 1.208, 95% CI 1.096-1.332) are significant predictors of CVD.

CONCLUSIONS

Age, diastolic function, and strain value in patients with breast cancer who underwent chemotherapy has a long-term effect on CVD. Therefore, it is important to consider ethnic and age-specific risks for CVD in breast cancer survivors.

Management of cardiac disease in cancer patients throughout oncological treatment: ESMO consensus recommendations

Cancer and cardiovascular (CV) disease are the most prevalent diseases in the developed world. Evidence increasingly shows that these conditions are interlinked through common risk factors, coincident in an ageing population, and are connected biologically through some deleterious effects of anticancer treatment on CV health. Anticancer therapies can cause a wide spectrum of short- and long-term cardiotoxic effects. An explosion of novel cancer therapies has revolutionised this field and dramatically altered cancer prognosis. Nevertheless, these new therapies have introduced unexpected CV complications beyond heart failure. Common CV toxicities related to cancer therapy are defined, along with suggested strategies for prevention, detection and treatment. This ESMO consensus article proposes to define CV toxicities related to cancer or its therapies and provide guidance regarding prevention, screening, monitoring and treatment of CV toxicity. The majority of anticancer therapies are associated with some CV toxicity, ranging from asymptomatic and transient to more clinically significant and long-lasting cardiac events. It is critical however, that concerns about potential CV damage resulting from anticancer therapies should be weighed against the potential benefits of cancer therapy, including benefits in overall survival. CV disease in patients with cancer is complex and treatment needs to be individualised. The scope of cardio-oncology is wide and includes prevention, detection, monitoring and treatment of CV toxicity related to cancer therapy, and also ensuring the safe development of future novel cancer treatments that minimise the impact on CV health. It is anticipated that the management strategies discussed herein will be suitable for the majority of patients. Nonetheless, the clinical judgment of physicians remains extremely important; hence, when using these best clinical practices to inform treatment options and decisions, practitioners should also consider the individual circumstances of their patients on a case-by-case basis.

Non-Invasive Hemodynamic Whole-Body Bioimpedance Indices for the Early Detection of Cancer Treatment-Related Cardiotoxicity: A Retrospective Observational Study

<b><i>Introduction:</i></b> Patients undergoing chemotherapy are extremely vulnerable to cardiotoxicity. Early detection of cardiac dysfunction is of vital importance to optimize the management of these patients. <b><i>Objective:</i></b> The aim of this study was to test the effectiveness of non-invasive hemodynamic whole-body bioimpedance (WBI) technology as a modality to detect heart failure in patients undergoing chemotherapy treatment. <b><i>Methods:</i></b> This retrospective observational trial included 84 patients treated at the cardio-oncology outpatient clinic of the Rabin Medical Center. Clinical assessments were performed including biomarker testing and measurement of hemodynamic and volume status parameters as measured by WBI. <b><i>Results:</i></b> We included 84 patients with a median age of 64.8 years, and 40.5% were males. Clinical heart failure was detected in 43% of the whole group. Patients were divided into two groups according to baseline NT-proBNP levels with a cut-off of 900 pg/mL. Left ventricular ejection fraction did not differ between the groups. Those with NT-proBNP &#x3e;900 pg/mL had lower levels of stroke index, cardiac index, and Granov-Goor index (GGI; 25.9 vs. 34.0, 2.0 vs. 2.3, 8.3 vs. 11.4, respectively, with <i>p</i> &#x3c; 0.001 for all comparisons). The optimal cut-off value for the GGI to detect NT-proBNP &#x3e;900 pg/mL was 8.3. The area under the curve of a GGI cut-off &#x3c;8.3 to detect NT-proBNP &#x3e;900 pg/mL was 0.81 (positive predictive value 95% and negative predictive value 72%), with a 51% sensitivity and 98% specificity. <b><i>Conclusion:</i></b> GGI, a parameter measured by WBI, can reliably correlate to biomarker evidence of heart failure in patients after chemotherapy. Its use as a screening tool for cardiotoxicity in patients with ongoing anticancer therapy is promising.

Breast Cancer: Lifestyle, the Human Gut Microbiota/Microbiome, and Survivorship

Patients with a current diagnosis of breast cancer are enjoying dramatic cure rates and survivorship secondary to an increase in awareness, earlier detection, and more effective therapies. Although strategies such as Breast Cancer Awareness Month in October focus on early detection, lifestyle changes are seldom discussed other than dietary concerns and physical activity. Lifestyle modifications centered on diet and exercise have been demonstrated to affect overall disease-free survival in breast cancer. Since the early 2000s, the role of the human gut microbiota and its relation to breast cancer has become a major area of interest in the scientific and medical community. We live and survive owing to the symbiotic relationship with the microorganisms within us: the human microbiota. Scientific advances have identified a subset of the gut microbiota: the estrobolome, those bacteria that have the genetic capability to metabolize estrogen, which plays a key role in most breast cancers. Recent research provides evidence that the gut microbiome plays a substantial role in estrogen regulation. Gut microbiota diversity appears to be an essential component of overall health, including breast health. Future research attention should include a more extensive focus on the role of the human gut microbiota in breast cancer.

Radiobiological models in prediction of radiation cardiotoxicity

Coronary disease induced by previous radiotherapy is the most common cause of death among patients treated with radiotherapy for cancer. Risk factors that may affect the frequency and intensity of radiotherapy's cardiac toxicity are primarily the radiation dose and the volume of the heart exposed to radiation. The prolonged survival time of patients after radiotherapy, but also the intensive development of modern radiotherapy techniques results in the necessity of precise estimation of both tumor control probability, and the risk of normal tissue damage, thus the models describing the probability of complications in normal tissues have also been developed. The response from the cardiovascular system to high-dose radiation is known and associated with a pro-inflammatory response. However, the effect of low doses may be completely different because it induces an anti-inflammatory response. Also, there is no unambiguous answer to the question of whether RICD is a deterministic effect. Moreover, there is a lack of literature data on the use of known radiobiological models to assess the risk of cardiovascular complications. The models described are general and concerns any healthy tissue. Therefore, when planning treatment for patients, particular attention should be paid to the dose and area of ​​the heart to be irradiated.

Cardiotoxicity and Cardiac Monitoring Among Chemotherapy-Treated Breast Cancer Patients

OBJECTIVES

This study sought to determine the rate of chemotherapy-related cardiotoxicity and to estimate adherence to recommendations for cardiac monitoring among breast cancer patients treated with chemotherapy.

BACKGROUND

Heart failure (HF) is a known complication associated with cancer therapies. Little is known regarding the rate of chemotherapy-related cardiotoxicity and adherence to recommendations for cardiac monitoring among chemotherapy-treated breast cancer patients.

METHODS

Patients >18 years of age with a diagnosis of nonmetastatic invasive breast cancer between 2009 and 2014, treated with chemotherapy within 6 months of their diagnosis, were identified in the Truven Health MarketScan (IBM Watson Health, Cambridge, Massachusetts) database. HF, comorbidities, and treatment details were identified using diagnosis and billing codes. Analyses included descriptive statistics, Cox proportional hazard regression, and logistic regression.

RESULTS

A total of 16,456 patients were included; the median age was 56 years old. Cardiotoxicity was identified in 4.2% of patients. Therapy with trastuzumab (hazard ratio [HR]: 2.01; 95% confidence interval [CI]: 1.72 to 2.36) and anthracyclines (HR: 1.53; 95% CI: 1.30 to 1.80), Deyo comorbidity scores (HR: 1.38; 95% CI: 1.15 to 1.66; HR: 2.47; 95% CI: 1.94 to 3.15 for scores of 1 and ≥2, respectively), hypertension (HR: 1.28, 95% CI: 1.09 to 1.51), and valve disease (HR: 1.93; 95% CI: 1.48 to 2.51) were associated with an increased risk of cardiotoxicity. Patients ≤35 years of age (HR: 0.37; 95% CI: 0.19 to 0.72) and 36 to 49 years of age (HR: 0.49; 95% CI: 0.38 to 0.62) were less likely to have cardiotoxicity than patients 65 years of age and older. Among 4,325 patients treated with trastuzumab, guideline-adherent cardiac monitoring was identified in 46.2% of patients. Therapies using anthracyclines (odds ratio [OR]: 1.58; 95% CI: 1.35 to 1.87), taxanes (OR: 1.63; 95% CI: 1.27 to 2.08), and radiation (OR: 1.22; 95% CI: 1.08 to 1.39) were associated with guideline-adherent monitoring.

CONCLUSIONS

HF is an uncommon complication of breast cancer therapies. The risk was higher among patients treated with trastuzumab or anthracyclines and lower in younger patients. Cardiac monitoring among trastuzumab-treated patients should be a priority among high-risk patients and in the presence of comorbidities or other chemotherapies such as those using anthracyclines.

An effective patient training for deep inspiration breath hold technique of left-sided breast on computed tomography simulation procedure at King Chulalongkorn Memorial Hospital

Purpose

To observe the effectiveness of the practical instruction sheet and the educational video for left-sided breast treatment in a patient receiving deep inspiration breath hold (DIBH) technique. Two parameters, simulation time and patient satisfaction, were assessed through the questionnaire.

Methods

Two different approaches, which were the instruction sheet and educational video, were combinedly used to assist patients during DIBH procedures. The guideline was assigned at least 1 week before the simulation date. On the simulation day, patients would fill the questionnaire regarding their satisfaction with the DIBH instruction. The questionnaire was categorized into five levels: extremely satisfied to dissatisfied, sequentially. The patients were divided into four groups: not DIBH technique, DIBH without instruction materials, the DIBH with instruction sheet or educational video, and DIBH with both of instruction sheet and educational video.

Results

Total number of 112 cases of left-sided breast cancer were analyzed. The simulation time during DIBH procedure significantly reduced when patients followed the instruction. There was no significant difference in simulation time on the DIBH procedures between patient compliance via instruction sheet or educational video or even following both of them. The excellent level was found at 4.6 ± 0.1 and 4.5 ± 0.1, for patients coaching via instruction sheet as well as on the educational video, respectively.

Conclusion

Patient coaching before simulation could potentially reduce the lengthy time in the simulation process for DIBH technique. Practicing the DIBH technique before treatment is strongly advised.

BNP as a marker for early prediction of anthracycline-induced cardiotoxicity in patients with breast cancer

Anthracycline chemotherapy serves an important role in treating patients with breast cancer but is associated with cardiotoxicity. Although brain natriuretic peptide (BNP) is not the ideal marker for detecting the presence of diseases of the heart, several studies have demonstrated the predictive utility of BNP in the diagnosis of anthracycline-induced cardiotoxicity (AIC). The aim of the present study was to evaluate the role of BNP as a marker for the early prediction of AIC in patients with breast cancer. In the present study, a total of 149 patients with breast cancer who received anthracycline therapy were evaluated. The levels of BNP and echocardiography were detected during the anthracycline-based chemotherapy and patients were followed up after chemotherapy to determine the cardiotoxicity-free survival times. In the patients who received chemotherapy, an increase in the levels of BNP was observed. The concentration of BNP was significantly higher in the cardiotoxicity group during anthracycline chemotherapy (P=0.022) compared with the non-cardiotoxicity group and it was an independent predictor of cardiotoxicity (P=0.028). The optimal diagnostic threshold of BNP after the last anthracycline chemotherapy treatment was 107.9 pg/ml, the diagnostic sensitivity was 0.538, the specificity was 0.794, the Youden index was 0.332, the positive predictive value was 0.583 and the negative predictive value was 0.762. Based on the BNP threshold, a log-rank test was performed and it was determined that the cardiotoxicity-free survival rate of the group with higher levels of BNP was always lower compared with the group with lower levels of BNP. BNP elevation was associated with cardiotoxicity during the anthracycline chemotherapy. Detecting BNP after the final treatment of anthracycline chemotherapy may contribute to the early detection of cardiotoxicity.

Evaluation of fixed-jaw IMRT and tangential partial-VMAT radiotherapy plans for synchronous bilateral breast cancer irradiation based on a dosimetric study

PURPOSE

To investigate the fixed-jaw intensity-modulated radiotherapy (F-IMRT) and tangential partial volumetric modulated arc therapy (tP-VMAT) treatment plans for synchronous bilateral breast cancer (SBBC).

MATERIALS AND METHOD

Twelve SBBC patients with pTis-2N0M0 stages who underwent whole-breast irradiation after breast-conserving surgery were planned with F-IMRT and tP-VMAT techniques prescribing 42.56 Gy (2.66 Gy*16f) to the breast. The F-IMRT used 8-12 jaw-fixed tangential fields with single (sF-IMRT) or two (F-IMRT) isocenters located under the sternum or in the center of the left and right planning target volumes (PTVs), and tP-VMAT used 4 tangential partial arcs with two isocenters located in the center of the left and right PTVs. Plan evaluation was based on dose-volume histogram (DVH) analysis. Dosimetric parameters were calculated to evaluate plan quality; total monitor units (MUs), and the gamma analysis for patient-specific quality assurance (QA) were also evaluated.

RESULTS

For PTVs, the three plans had similar Dmean and conformity index (CI) values. F-IMRT showed a slightly better target coverage according to the V100% values and demonstrated an obvious reduction in V105% and Dmax compared with the values observed for sF-IMRT and tP-VMAT. Compared with tP-VMAT, sF-IMRT was slightly better in terms of V100% , V105% and Dmax . In addition, F-IMRT achieved the best homogeneity index (HI) values for PTVs. Concerning healthy tissue, tP-VMAT had an advantage in minimizing the high dose volume. The MUs of the tP-VMAT plan were decreased approximately 1.45 and 1 times compared with the sF-IMRT and F-IMRT plans, respectively, and all plans passed QA. For the lungs, heart and liver, F-IMRT achieved the smallest values in terms of Dmean and showed a significant difference compared with tP-VMAT. Simultaneously, sF-IMRT was also superior to tP-VMAT. For the coronary artery, tP-VMAT achieved the lowest Dmean , while the value for F-IMRT was 2.24% lower compared with sF-IMRT. For all organs at risk (OARs), tP-VMAT was superior at the high dose level. In contrast, sF-IMRT and F-IMRT were obviously superior at the low dose level. The sF-IMRT and F-IMRT plans showed consistent trends.

CONCLUSION

All treatment plans for the provided techniques were of high quality and feasible for SBBC patients. However, we recommend F-IMRT with a single isocenter as a priority technique because of the tremendous advantage of local hot spot control in PTVs and the reduced dose to OARs at low dose levels. When the irradiated dose to the lungs and heart exceed the clinical restriction, two isocenter F-IMRT can be used to maximize OAR sparing. Additionally, tP-VMAT can be adopted for improving cold spots in PTVs or high-dose exposure to normal tissue when the interval between PTVs is narrow.