Exercise intervention decreases acute and late doxorubicin-induced cardiotoxicity

Effectiveness of Therapeutic Exercise for Children Undergoing Treatment for Cancer: A Systematic Review

PURPOSE

To evaluate the effectiveness of therapeutic physical exercise (TPE) interventions on the physical functioning, psychosocial well-being, and quality of life (QoL) of children undergoing treatment for cancer.

METHOD

Systematic review: databases were searched in April 2023. Selection criteria: children (<18 years old) undergoing treatment for cancer or a malignant neoplasm, randomized controlled trial design, utilization of TPE, and including physical and psychosocial outcomes. Internal validity was measured with Physiotherapy Evidence Database scale.

RESULTS

Seven randomized controlled trials were included. Most studies showed that strength, fatigue, and QoL improved after the intervention. Cardiorespiratory capacity through 6-minute walk test and physical activity levels were better in the experimental groups. No changes were noted in other variables.

CONCLUSIONS

This review supports the importance of a TPE program during cancer treatment, with the aim of maintaining physical capacities and counteracting physical inactivity.

New insights into cardioprotection in breast cancer patients undergoing physical exercise during chemotherapy: A systematic review and meta-analysis

BACKGROUND

Chemotherapy associated with breast cancer often induces cardiotoxicity, which compromises patients' health and quality of life.

OBJECTIVE

To verify the effect of physical exercise on chemotherapy-induced cardiotoxicity, through the assessment of cardiac function in patients with breast cancer.

METHODS

A systematic review and meta-analysis of clinical studies was conducted to evaluate the effectiveness of physical training in chemotherapy-induced cardiomyopathy in the PubMed, Web of Sciences and Scopus databases. Thirteen studies were included in the systematic review and eleven studies in the data meta-analysis.

RESULTS

Global longitudinal strain presents a cardioprotective effect when compared to the control group (Heterogeneity: Chi² = 12.81, df = 10 (p = 0.23); I² = 22 %.) Test for global effect: Z = 2, 13 (p = 0.03). Physical training is more effective (test for subgroup differences, p = 0.031) in attenuating the impairment of %GLS induced by chemotherapy if performed concomitantly with exposure to chemotherapy (95 % CI; Heterogeneity: Chi² = 7.49, gl = 5 (p = 0.19); I² = 33 %; Test for global effect: Z = 2.33 (p = 0.02) when compared after chemotherapy treatment, or in the long term (for 12 months or more). However, without benefits in LVEF (Heterogeneity: Chi² = 42.14, df = 10 (p < 0.00001); I² = 76 %) Test for global effect: Z = 2.51 (p = 0.01) Conclusion: Exercise training is a cardioprotective approach in breast cancer patients who experience chemotherapy-induced cardiotoxicity. Exercise during exposure to chemotherapy has greater effects on preserving cardiac function.

Exercise Preconditioning Preserves Cardiac Function and Enhances Cardiac Recovery Following Dobutamine Stimulation in Doxorubicin-Treated Rat Hearts

ABSTRACT

Exercise preconditioning has been shown to protect against doxorubicin (DOX)-induced cardiac dysfunction when hearts are maintained under resting conditions. However, it is unclear whether this exercise-induced protective effect is maintained when the heart is challenged with the β 1 -adrenergic receptor agonist dobutamine (DOB), which mimics acute exercise stress. Fischer 344 rats were randomly assigned to sedentary (SED) or voluntary wheel running (WR) groups for 10 weeks. At week 11, rats were treated with either 15 mg/kg DOX or saline. Five days later, ex vivo cardiac function was assessed using an isolated working heart model at baseline, during the infusion of 7.5 μg·kg -1 ·min -1 DOB, and during recovery. DOB infusion significantly increased left ventricular developed pressure (LVDP), maximal (dP/dt max ) and minimal (dP/dt min ) rate of left ventricular pressure development, and heart rate in all groups ( P < 0.05). SED + DOX also showed a lower baseline and recovery LVDP than WR + DOX (83 ± 12 vs. 109 ± 6 mm Hg baseline, 76 ± 11 vs. 100 ± 10 mm Hg recovery, P < 0.05). WR + DOX showed higher dP/dt max and lower dP/dt min when compared with SED + DOX during DOB infusion (7311 ± 1481 vs. 5167 ± 1436 mm Hg/s and -4059 ± 1114 vs.-3158 ± 1176 mm Hg/s, respectively). SED + DOX dP/dt max was significantly lower during baseline and during recovery when compared with all other groups ( P < 0.05). These data suggest that exercise preconditioning preserved cardiac function after DOX exposure even when the heart is challenged with DOB, and it appeared to preserve the heart's ability to recover from this functional challenge.

Patient attitudes and experiences towards exercise during oncological treatment. A qualitative systematic review

PURPOSE

Exercise and physical activity (PA) during oncological treatment have many benefits. However, PA levels and adherence are often low. This systematic review of qualitative literature aims to explore the experience and the perceived barriers and facilitators to exercise and physical activity during treatment.

METHODS

A systematic search of the published literature was carried out in the Embase and Medline databases; full details for the protocol can be found in the Prospero database (CRD42022371206). Studies eligible for inclusion were qualitative and included participants that were either currently undergoing oncological treatment or had finished treatment within the last 6 months. The findings from each study were tabulated and synthesised into analytical themes.

RESULTS

Eighteen full texts from 309 studies met inclusion criteria with a total of 420 participants including both curative and palliative treatment intents. Four overarching themes were generated: (1) Facilitators; (2) Barriers; (3) Experience of PA/exercise and (4) Transforming attitudes. Sub-themes that showed perceptions of PA or exercise during treatment were positive, and seeing personal positive change was highly motivating, especially in a group class setting. Barriers included lack of support or guidance from healthcare professionals (HCPs), environmental challenges and disease burden/fear or worsening symptoms.

CONCLUSIONS

Despite having positive perceptions of exercise and PA during oncological treatment, there are significant barriers impacting participation. Lack of support from HCPs and fear of worsening symptoms were significant barriers. Future research should focus on impacting these barriers to ultimately improve PA and exercise levels in those undergoing oncological treatment.

An update of the molecular mechanisms underlying anthracycline induced cardiotoxicity

Anthracycline drugs mainly include doxorubicin, epirubicin, pirarubicin, and aclamycin, which are widely used to treat a variety of malignant tumors, such as breast cancer, gastrointestinal tumors, lymphoma, etc. With the accumulation of anthracycline drugs in the body, they can induce serious heart damage, limiting their clinical application. The mechanism by which anthracycline drugs cause cardiotoxicity is not yet clear. This review provides an overview of the different types of cardiac damage induced by anthracycline-class drugs and delves into the molecular mechanisms behind these injuries. Cardiac damage primarily involves alterations in myocardial cell function and pathological cell death, encompassing mitochondrial dysfunction, topoisomerase inhibition, disruptions in iron ion metabolism, myofibril degradation, and oxidative stress. Mechanisms of uptake and transport in anthracycline-induced cardiotoxicity are emphasized, as well as the role and breakthroughs of iPSC in cardiotoxicity studies. Selected novel cardioprotective therapies and mechanisms are updated. Mechanisms and protective strategies associated with anthracycline cardiotoxicity in animal experiments are examined, and the definition of drug damage in humans and animal models is discussed. Understanding these molecular mechanisms is of paramount importance in mitigating anthracycline-induced cardiac toxicity and guiding the development of safer approaches in cancer treatment.

An electrochemical biosensor based on DNA tetrahedron nanoprobe for sensitive and selective detection of doxorubicin

Doxorubicin (DOX) is a clinical chemotherapeutic drug and patients usually suffer from dose-dependent cytotoxic and side effects during chemotherapy process with DOX. Therefore, developing a reliable strategy for DOX analysis in biological samples for dosage guidance during chemotherapy process is of great significance. Herein, a sensitive and selective electrochemical biosensor for DOX detection was designed based on gold nanoparticles (AuNPs) and DNA tetrahedron (TDN) nanoprobe bifunctional glassy carbon electrode that could detect DOX in human serum and cell lysate samples. AuNPs not only could enhance electron transfer efficiency and detection sensitivity, but also could improve the biocompatibility of electrode. TDN nanoprobes were employed as specific DOX bind sites that could bind abundant DOX through intercalative characteristics to contribute to sensitive and selective detection. Under the optimal conditions, the proposed TDN nanoprobes-based DOX biosensor exhibited a wide linear range that ranged from 1.0 nM to 50 μM and a low detection limit that was 0.3 nM. Moreover, the proposed DOX biosensor displayed nice selectivity, reproducibility and stability, and was successfully applied for DOX detection in human serum and cell lysate samples. These promising results maybe pave a way for DOX dosage guidance and therapeutic efficacy optimization in clinic.

Voluntary wheel running reduces tumor growth and increases capillarity in the heart during doxorubicin chemotherapy in a murine model of breast cancer

Introduction: The possible beneficial effects of physical activity during doxorubicin treatment of breast cancer need further investigation as many of the existing studies have been done on non-tumor-bearing models. Therefore, in this study, we aim to assess whether short-term voluntary wheel-running exercise during doxorubicin treatment of breast cancer-bearing mice could induce beneficial cardiac effects and enhance chemotherapy efficacy. Methods: Murine breast cancer I3TC cells were inoculated subcutaneously to the flank of female FVB mice (n = 16) that were divided into exercised and non-exercised groups. Two weeks later, doxorubicin treatment was started via intraperitoneal administration (5 mg/kg weekly for 3 weeks). Organs were harvested a day after the last dose. Results: The tumor volume over time was significantly different between the groups, with the exercising group having lower tumor volumes. The exercised group had increased body weight gain, tumor apoptosis, capillaries per cardiomyocytes, and cardiac lactate dehydrogenase activity compared to the unexercised group, but tumor blood vessel density and maturation and tumor and cardiac HIF1-α and VEGF-A levels did not differ from those of the non-exercised group. Discussion: We conclude that even short-term light exercise such as voluntary wheel running exercise can decrease the subcutaneous mammary tumor growth, possibly via increased tumor apoptosis. The increase in cardiac capillaries per cardiomyocytes may also have positive effects on cancer treatment outcomes.

Circulating microRNAs and Cytokines as Prognostic Biomarkers for Doxorubicin-Induced Cardiac Injury and for Evaluating the Effectiveness of an Exercise Intervention

PURPOSE

To define a set of biomarkers that can be used to identify patients at high risk of developing late doxorubicin (DOX)-induced cardiac morbidity with the goal of focused monitoring and early interventions.

EXPERIMENTAL DESIGN

Mice received phosphate buffered saline or DOX 2.5 mg/kg 2x/week for 2 weeks. Blood samples were obtained before and after therapy for quantification of miRNAs (6 and 24 hours), cytokines (24 hours), and troponin (24 hours, 4 and 6 weeks). Cardiac function was evaluated using echocardiography before and 24 hours after therapy. To assess the effectiveness of exercise intervention in preventing DOX-induced cardiotoxicity blood samples were collected from mice treated with DOX or DOX + exercise. Plasma samples from 13 DOX-treated patients with sarcoma were also evaluated before and 24 hours after therapy.

RESULTS

Elevations in plasma miRNA-1, miRNA-499 and IL1α, IL1β, and IL6 were seen in DOX-treated mice with decreased ejection fraction and fractional shortening 24 hours after DOX therapy. Troponin levels were not elevated until 4 weeks after therapy. In mice treated with exercise during DOX, there was no elevation in these biomarkers and no change in cardiac function. Elevations in these biomarkers were seen in 12 of 13 patients with sarcoma treated with DOX.

CONCLUSIONS

These findings define a potential set of biomarkers to identify and predict patients at risk for developing acute and late cardiovascular diseases with the goal of focused monitoring and early intervention. Further studies are needed to confirm the predictive value of these biomarkers in late cardiotoxicity.

Early skeletal muscle loss in adolescent and young adult cancer patients treated with anthracycline chemotherapy

BACKGROUND

Early skeletal muscle loss has been observed in adolescent and young adult (AYA) sarcoma patients undergoing treatment. Identification of individuals within the AYA populace that are at greatest risk of anthracycline-induced skeletal muscle loss is unknown. Moreover, investigations which seek out underlying causes of skeletal muscle degradation during chemotherapy are critical for understanding, preventing, and reducing chronic health conditions associated with poor skeletal muscle status.

METHODS

Computed tomography (CT) scans were used to investigate changes in skeletal muscle of 153 AYA sarcoma and Hodgkin lymphoma patients at thoracic vertebra 4 after anthracycline treatment. Images were examined at three time points during the first year of treatment. In parallel, we used translational juvenile mouse models to assess the impact of doxorubicin (DOX) in the soleus and gastrocnemius on muscle wasting.

RESULTS

Significant reductions in total skeletal muscle index and density were seen after chemotherapy in AYA cancer patients (p < 0.01 & p = 0.04, respectively). The severity of skeletal muscle loss varied by subgroup (i.e., cancer type, sex, and treatment). Murine models demonstrated a reduction in skeletal muscle fiber cross-sectional area, increased apoptosis and collagen volume for both the soleus and gastrocnemius after DOX treatment (all p < 0.05). After DOX, hindlimb skeletal muscle blood flow was significantly reduced (p < 0.01).

CONCLUSION

Significant skeletal muscle loss is experienced early during treatment in AYA cancer patients. Reductions in skeletal muscle blood flow may be a key contributing factor to anthracycline doxorubicin induced skeletal muscle loss.

Time to embed physical activity within usual care in cancer services: A qualitative study of cancer healthcare professionals' views at a single centre in England

PURPOSE

An increasing number of people affected by cancer (PABC) are living longer lives as treatment continues to advance. There is growing evidence for physical activity (PA) supporting health in this population before, during and after cancer treatment, but PA advice is not part of usual care. This study investigates views of frontline oncology healthcare professionals (HCPs) in one NHS teaching hospital in England to understand the role of PA advice across cancer services.

MATERIALS AND METHODS

This was a qualitative study interviewing HCPs and using thematic analysis.

RESULTS

Four main themes were identified: 1. Awareness of the roles of PA in cancer; 2. Patient-specific factors in rehabilitation; 3. Cancer-specific factors in rehabilitation; 4. Barriers and opportunities to integrating PA within usual care. HCPs' awareness of the role of PA in cancer rehabilitation was low overall and PA was found not to be embedded within rehabilitation. Contrastingly, there was awareness of PA's potential to impact disease and treatment-related outcomes positively. Ideas for PA integration included training for staff and giving PA advice within consultations.

CONCLUSIONS

Low awareness of benefits of PA-based rehabilitation and lack of integration in usual care contrasted with HCPs' interest in this area's potential. Training HCPs to begin the conversation with patients affected by cancer in teachable moments may increase patient access.Implications for rehabilitationIntegrating physical activity education and training for trainees and existing healthcare professionals workforce would help embed physical activity into routine clinical practice.Brief advice intervention training during every consultation, such as providing relevant individualised information and signposting, can be impactful.Physical activity within a broader cancer rehabilitation programme should be integrated as standard for every cancer patient.Individualised plans may include prehabilitation, restorative rehabilitation and palliative rehabilitation.Patient preferences and the patient experience should continue to shape service design.There is a need to ensure physical activity advice is consistent throughout healthcare settings and not fragmented between primary, secondary and tertiary care.

A systematic review of exercise protocols applied to athymic mice in tumor-related experiments

Athymic mice are unable to produce T-cells and are then characterized as immunodeficient. This characteristic makes these animals ideal for tumor biology and xenograft research. New non-pharmacological therapeutics are required owing to the exponential increase in global oncology costs over the last 10 years and the high cancer mortality rate. In this sense, physical exercise is regarded as a relevant component of cancer treatment. However, the scientific community lacks information regarding the effect of manipulating training variables on cancer in humans, and experiments with athymic mice. Therefore, this systematic review aimed to address the exercise protocols used in tumor-related experiments using athymic mice. The PubMed, Web of Science, and Scopus databases were searched without restrictions on published data. A combination of key terms such as athymic mice, nude mice, physical activity, physical exercise, and training was used. The database search retrieved 852 studies (PubMed, 245; Web of Science, 390; and Scopus, 217). After title, abstract, and full-text screening, 10 articles were eligible. Based on the included studies, this report highlights the considerable divergences in the training variables adopted for this animal model. No studies have reported the determination of a physiological marker for intensity individualization. Future studies are recommended to explore whether invasive procedures can result in pathogenic infections in athymic mice. Moreover, time-consuming tests cannot be applied to experiments with specific characteristics such as tumor implantation. In summary, non-invasive, low-cost, and time-saving approaches can suppress these limitations and improve the welfare of these animals during experiments.

Creatine and Resistance Training: A Combined Approach to Attenuate Doxorubicin-Induced Cardiotoxicity

Doxorubicin (DOX), a potent chemotherapy agent, useful in the treatment of solid tumors, lymphomas, and leukemias, is limited by its potentially lethal cardiotoxicity. However, exercise has been consistently shown to mitigate the side effects of DOX, including cardiotoxicity. To date, most studies examining the relationship between exercise and DOX-induced cardiotoxicity have focused on aerobic exercise, with very few examining the role of anerobic activity. Therefore, this investigation explored the potential of creatine (CR) and resistance training (RT) in preserving cardiac health during DOX therapy. Male Sprague-Dawley rats were grouped into RT, RT + CR, sedentary (SED), and SED + CR, with each division further branching into saline (SAL) or DOX-treated subsets post-10 weeks of RT or SED activity. RT comprised progressive training utilizing specialized cages for bipedal stance feeding. CR-treated groups ingested water mixed with 1% CR monohydrate and 5% dextrose, while control animals received 5% dextrose. At week 10, DOX was administered (2 mg/kg/week) over 4-weeks to an 8 mg/kg cumulative dose. Cardiac function post-DOX treatment was assessed via transthoracic echocardiography. Left ventricular diameter during diastole was lower in DOX + CR, RT + DOX, and RT + CR + DOX compared to SED + DOX (p < 0.05). Additionally, cardiac mass was significantly greater in RT + CR + DOX SED + DOX animals (p < 0.05). These results suggest RT and CR supplementation, separately and in combination, could attenuate some measures of DOX-induced cardiotoxicity and may offer a cost-effective way to complement cancer treatments and enhance patient outcomes. More investigations are essential to better understand CR's prolonged effects during DOX therapy and its clinical implications.

Cellular Mechanisms Mediating Exercise-Induced Protection against Cardiotoxic Anthracycline Cancer Therapy

Anthracyclines such as doxorubicin are widely used chemotherapy drugs. A common side effect of anthracycline therapy is cardiotoxicity, which can compromise heart function and lead to dilated cardiomyopathy and heart failure. Dexrazoxane and heart failure medications (i.e., beta blockers and drugs targeting the renin-angiotensin system) are prescribed for the primary prevention of cancer therapy-related cardiotoxicity and for the management of cardiac dysfunction and symptoms if they arise during chemotherapy. However, there is a clear need for new therapies to combat the cardiotoxic effects of cancer drugs. Exercise is a cardioprotective stimulus that has recently been shown to improve heart function and prevent functional disability in breast cancer patients undergoing anthracycline chemotherapy. Evidence from preclinical studies supports the use of exercise training to prevent or attenuate the damaging effects of anthracyclines on the cardiovascular system. In this review, we summarise findings from experimental models which provide insight into cellular mechanisms by which exercise may protect the heart from anthracycline-mediated damage, and identify knowledge gaps that require further investigation. Improved understanding of the mechanisms by which exercise protects the heart from anthracyclines may lead to the development of novel therapies to treat cancer therapy-related cardiotoxicity.

Chemotherapy Induced Cardiotoxicity: A State of the Art Review on General Mechanisms, Prevention, Treatment and Recent Advances in Novel Therapeutics

As medicine advances to employ sophisticated anticancer agents to treat a vast array of oncological conditions, it is worth considering side effects associated with several chemotherapeutics. One adverse effect observed with several classes of chemotherapy agents is cardiotoxicity which leads to reduced ejection fraction (EF), cardiac arrhythmias, hypertension and Ischemia/myocardial infarction that can significantly impact the quality of life and patient outcomes. Research into possible mechanisms has elucidated several mechanisms, such as ROS generation, calcium overload and apoptosis. However, there is a relative scarcity of literature detailing the relationship between the exact mechanism of cardiotoxicity for each anticancer agent and observed clinical effects. This review comprehensively describes cardiotoxicity associated with various classes of anticancer agents and possible mechanisms. Further research exploring possible mechanisms for cardiotoxicity observed with anticancer agents could provide valuable insight into susceptibility for developing symptoms and management guidelines. Chemotherapeutics are associated with several side effects. Several classes of chemotherapy agents cause cardiotoxicity leading to a reduced ejection fraction (EF), cardiac arrhythmias, hypertension, and Ischemia/myocardial infarction. Research into possible mechanisms has elucidated several mechanisms, such as ROS generation, calcium overload, and apoptosis. However, there is a relative scarcity of literature detailing the relationship between the exact mechanism of cardiotoxicity for each anticancer agent and observed clinical effects. This review describes cardiotoxicity associated with various classes of anticancer agents and possible mechanisms. Further research exploring mechanisms for cardiotoxicity observed with anticancer agents could provide insight that will guide management.

The beneficial role of exercise in preventing doxorubicin-induced cardiotoxicity

Doxorubicin is a highly effective chemotherapeutic agent widely used to treat a variety of cancers. However, the clinical application of doxorubicin is limited due to its adverse effects on several tissues. One of the most serious side effects of doxorubicin is cardiotoxicity, which results in life-threatening heart damage, leading to reduced cancer treatment success and survival rate. Doxorubicin-induced cardiotoxicity results from cellular toxicity, including increased oxidative stress, apoptosis, and activated proteolytic systems. Exercise training has emerged as a non-pharmacological intervention to prevent cardiotoxicity during and after chemotherapy. Exercise training stimulates numerous physiological adaptations in the heart that promote cardioprotective effects against doxorubicin-induced cardiotoxicity. Understanding the mechanisms responsible for exercise-induced cardioprotection is important to develop therapeutic approaches for cancer patients and survivors. In this report, we review the cardiotoxic effects of doxorubicin and discuss the current understanding of exercise-induced cardioprotection in hearts from doxorubicin-treated animals.

Protective effect of urotensin II receptor antagonist urantide and exercise training on doxorubicin-induced cardiotoxicity

Doxorubicin (DOX) has a wide antitumor spectrum, but its adverse cardiotoxicity may lead to heart failure. Urotensin II (UII) is the most potent vasoconstrictor in mammals. It plays a role by activating the UII receptor (UT), the orphan G protein-coupled receptor (GPR14), collectively referred to as the UII/UT system. In the new version of "Chinese expert consensus on cardiac rehabilitation of chronic heart failure," it is pointed out that exercise rehabilitation is the cornerstone of cardiac rehabilitation. In this study, in vitro and in vivo assessments were performed using DOX-treated H9C2 cells and rats. It was found that the UT antagonist Urantide and exercise training improved DOX-induced cardiac insufficiency, reduced DOX-induced cardiomyocyte apoptosis, improved the structural disorder of myocardial fibers, and inhibited DOX-induced myocardial fibrosis. Further studies showed that Urantide alleviated DOX-induced cardiotoxicity by downregulating the expression levels of the p38 mitogen-activated protein kinase signaling pathway.

Fatal heart disease in patients with bone and soft tissue sarcoma

Background/purpose

With improved cancer survivorship, non-cancer events, especially heart disease (HD), have become the underlying cause of death in cancer patients, but the risk of HD mortality in sarcoma patients remains poorly characterized. Therefore, our purpose was to: (1) identify sarcoma patients at the highest risk of fatal HD compared with the general population, (2) identify patients and sarcoma characteristics associated with a higher risk of HD death, and (3) determine if chemotherapy increased the risk of HD death in sarcoma patients.

Methods

From 1975 to 2016, we identified patients diagnosed with bone and soft tissue sarcoma from the Surveillance, Epidemiology, and End Results (SEER) database in the US. Standardized mortality ratios (SMRs) were evaluated using mortality data from the general population collected by the National Center for Health Statistics. This was the largest retrospective cohort study of fatal HD in individuals with sarcoma.

Results

In 80,905 sarcoma patients observed for 530,290 person-years, 3,350 deaths from HD were identified with a mortality of 631.7/100,000 person-years. The SMR of death from HD was 1.38 (95% CI: 1.33–1.42). The highest risks of death from HD were observed in patients with Ewing sarcoma (SMR = 5.44; 95% CI: 3.38–8.75) and osteosarcoma (SMR = 1.92; 95% CI: 1.55–2.38). Patients diagnosed at < 19 years old had the highest SMR in all age subgroups, and a higher risk of fatal HD relative to the general population was observed in sarcoma survivors diagnosed at < 85 years old. In patients diagnosed at < 19 years old, HD plurality occurred in those with Ewing sarcoma (29.4%) and osteosarcoma (32.4%) and at > 35 years old, HD plurality occurred in those diagnosed with liposarcoma (19.0%) and malignant fibro histiocytoma (MFH) (23.6%). For sarcoma survivors, HD mortality risks were highest within the first year after diagnosis (SMR = 1.31; 95% CI: 1.21–1.41), and this risk remained elevated throughout follow-up compared with the general population. Subgroup analyses indicated that chemotherapy significantly increased the risk of fatal HD in patients with localized osteosarcoma (Hazard ratio (HR) = 3.18; 95% CI: 1.24–8.13; P = 0.016), but not in patients with other histological sarcoma subtypes and clinical stages.

Conclusion

The risk of death from HD mainly varied in patients with different histological sarcoma subtypes and clinical stages. Chemotherapy increased the risk of fatal HD in patients with localized osteosarcoma. To lower the risk of fatal HD in patients with sarcoma, we call for enhanced multidisciplinary cooperation, including cardiologists and orthopedic surgeons.

Doxorubicin-induced cardiotoxicity is mediated by neutrophils through release of neutrophil elastase

The mechanisms by which Doxorubicin (Dox) causes acute and late cardiotoxicity are not completely understood. One understudied area is the innate immune response, and in particular the role of neutrophils in Dox-induced cardiotoxicity. Here, using echocardiography, flow cytometry and immunofluorescence staining, we demonstrated increased infiltration of neutrophils that correlated with decreased heart function, disruption of vascular structures and increased collagen deposition in the heart after Dox treatment. Depleting neutrophils protected the heart from Dox-induced cardiotoxicity and changes in vascular structure. Furthermore, our data using neutrophil elastase (NE) knock-out mice and the NE inhibitor AZD9668 suggest that neutrophils cause this damage by releasing NE and that inhibiting NE can prevent Dox-induced cardiotoxicity. This work shows the role of neutrophils and NE in Doxorubicin-induced cardiotoxicity for the first time and suggests a new possible therapeutic intervention.

Tracking the Stepwise Formation of a Water-Soluble Fluorescent Tb12 Cluster for Efficient Doxorubicin Detection

Doxorubicin (DOX) is an anthraquinone drug used for the efficient treatment of a variety of tumors in human beings. Unfortunately, its poor biodegradability causes incomplete metabolism in the body. Therefore, it is of great significance to synthesize a sensitive and selective material for DOX detection. In this paper, we report a water-soluble Tb₁₂ cluster and track its step-by-step formation (L → Tb₁L₁ → Tb₂L₁ → Tb₂L₂ → Tb₃L₂ → Tb₄L₂ → Tb₁₂L₆). Tb₁₂ can be used to determine the presence of DOX, which quenches the luminescence of the Tb₁₂ aqueous solution, and the detection limit can reach 13 nM (K_SV = 8.7 × 10⁵ M^-1). Tb₁₂ has advantages of high sensitivity and high selectivity for the detection of DOX in a simulated environment of human urine and serum.

Exercise intervention decreases acute and late doxorubicin-induced cardiotoxicity

BACKGROUND

Doxorubicin (Dox) is one of the most effective chemotherapy agents used to treat adolescent and young adult sarcoma patients. Unfortunately, Dox causes cardiotoxicities that compromise long-term survival. We investigated whether exercise prevented cardiotoxicity and increased survival following myocardial infarction.

METHODS

Juvenile mice received Dox, Dox + exercise (Exer), Dox then exercise or were exercised during and after Dox. Mice were evaluated by echocardiography and histology immediately after therapy and 12 weeks later. Mice subjected to permanent ligation of the left anterior descending artery 90 days after therapy were assessed for survival at 45 and 100 days.

RESULTS

Mice treated with Dox, but not Dox + Exer, had decreased ejection fraction (EF) and fractional shortening (FS) immediately after Dox therapy, which continued to deteriorate over 12 weeks with the development of diastolic failure and fibrosis. Acute Dox-induced cardiotoxicity was documented by induction of autophagy and abnormal mitochondria and vascular architecture with decreased pericytes. These abnormalities persisted 12 weeks after therapy. These acute and late changes were not seen in the Dox + Exer group. Initiating exercise after Dox therapy promoted recovery of EF and FS with no functional or histologic evidence of Dox-induced damage 12 weeks after therapy. Survival rates at 100 days after MI were 67% for control mice, 22% for mice that received Dox alone, and 56% for mice that received Dox + Exer.

CONCLUSIONS

Exercise inhibited both early and late Dox-induced cardiotoxicity and increased recovery from an ischemic event. Exercise interventions have the potential to decrease Dox-induced cardiac morbidity.