Vascular injury in cancer survivors

A cohort study on blood coagulation in childhood cancer survivors

Cancer survivors are at an increased risk of thromboembolism compared to the general pediatric population. Anticoagulant therapy decreases the risk of thromboembolism in cancer patients. We hypothesized that pediatric cancer survivors are in a chronically hypercoagulable state compared to healthy controls. Children who survived for more than five years from cancer diagnosis at the UT Health Science Center at San Antonio Cancer Survivorship Clinic were compared to healthy controls. The exclusion criteria were recent NSAID use or a history of coagulopathy. Coagulation analysis included platelet count, thrombin-antithrombin complexes (TAT), plasminogen activator inhibitor (PAI), routine coagulation assays, and thrombin generation with and without thrombomodulin. We enrolled 47 pediatric cancer survivors and 37 healthy controls. Platelet count was significantly lower in cancer survivors at a mean of 254 × 10⁹/L (95%CI: 234-273 × 10⁹/L) compared at 307 × 10⁹/L (283-331 × 10⁹/L) in healthy controls (p < 0.001), although not outside the normal range. Routine coagulation assays showed no differences, except for a significantly lower prothrombin time (PT) in cancer survivors (p < 0.004). Cancer survivors has significantly elevated biomarkers of the procoagulant state, such as TAT and PAI, compared to healthy controls (p < 0.001). A multiple logistic regression model controlling for age, BMI, gender, and race/ethnicity documented that a low platelet count, short prothrombin clot time, and higher procoagulant biomarkers (TAT and PAI) were significantly associated with past cancer therapy. Survivors of childhood cancer have a persistent procoagulant imbalance for more than five years after diagnosis. Further studies are needed to establish whether procoagulant imbalance increases the risk of thromboembolism in childhood cancer survivors.

Endothelial dysfunction as a complication of anti-cancer therapy

Recent strides in anti-cancer therapeutics have improved longevity and led to a growing population of cancer survivors, who are increasingly likely to die of other causes. Treatment-induced cardiotoxicity is a complication of several therapeutic agents with acute and long-term consequences for cancer patients. Vascular endothelial dysfunction is a precursor and hallmark of ischemic coronary disease and may play a role in anti-cancer therapy-induced cardiotoxicity. This review summarizes clinical evidence for endothelial dysfunction following anti-cancer therapy and extends the discussion to include the impact of therapeutic agents on conduit arteries and the microcirculation. We highlight the role of innate immune system activation and cross-talk between inflammation and oxidative stress as pathogenic mechanisms underlying anti-cancer therapy-induced vascular toxicity. Understanding the impact of anti-cancer agents on the vascular endothelium will inform therapeutic approaches to prevent or reverse treatment-induced cardiotoxicity and may serve as an important tool to predict, monitor, and prevent adverse cardiovascular outcomes in patients undergoing treatment.

Cardioprotective Strategies from Cardiotoxicity in Cancer Patients: A Comprehensive Review

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

Strategies to Prevent Cardiotoxicity

OPINION STATEMENT

Cardiovascular disease is a leading cause of death among cancer survivors. While the field of cardiology as a whole is driven by evidence generated through robust clinical trials, data in cardio-oncology is limited to a relatively small number of prospective clinical trials with heterogeneous groups of cancer patients. In addition, many pharmaceutical trials in oncology are flawed from a cardiovascular perspective because they exclude patients with significant cardiovascular (CV) history and have wide variation in the definitions of CV events and cardiotoxicity. Ultimately, oncology trials often underrepresent the possibility of cardiovascular events in a "real world" population. Thus, the signal for CV toxicity from a cancer treatment is often not manifested until phase IV studies; where we are often caught trying to mitigate the CV effects rather than preventing them. Most of the data about cardiotoxicity from cancer therapy and cardioprotective strategies has been developed from our experience in using anthracyclines for over 50 years with dramatic improvement in cancer survivorship. However, as we are in an era where cancer drug discovery is moving at lightning pace with increasing survival rates, it is imperative to move beyond anthracyclines and commit to research on the cardiovascular side effects of all aspects of cancer therapy with a focus on prevention. We emphasize the role of pre-cancer treatment CV assessment to anticipate cardiac issues and ultimately optimizing CV risk prior to cancer therapy as an opportunity to mitigate cardiovascular risk from cancer therapy.

Doxorubicin-Induced Cardiomyopathy in Children

Doxorubicin-induced cardiotoxicity in childhood cancer survivors is a growing problem. The population of patients at risk for cardiovascular disease is steadily increasing, as five-year survival rates for all types of childhood cancers continue to improve. Doxorubicin affects the developing heart differently from the adult heart and in a subset of exposed patients, childhood exposure leads to late, irreversible cardiomyopathy. Notably, the prevalence of late-onset toxicity is increasing in parallel with improved survival. By the year 2020, it is estimated that there will be 500,000 childhood cancer survivors and over 50,000 of them will suffer from doxorubicin-induced cardiotoxicity. The majority of the research to-date, concentrated on childhood cancer survivors, has focused mostly on clinical outcomes through well-designed epidemiological and retrospective cohort studies. Preclinical studies have elucidated many of the cellular mechanisms that elicit acute toxicity in cardiomyocytes. However, more research is needed in the areas of early- and late-onset cardiotoxicity and more importantly improving the scientific understanding of how other cells present in the cardiac milieu are impacted by doxorubicin exposure. The overall goal of this review is to succinctly summarize the major clinical and preclinical studies focused on doxorubicin-induced cardiotoxicity. As the prevalence of patients affected by doxorubicin exposure continues to increase, it is imperative that the major gaps in existing research are identified and subsequently utilized to develop appropriate research priorities for the coming years. Well-designed preclinical research models will enhance our understanding of the pathophysiology of doxorubicin-induced cardiotoxicity and directly lead to better diagnosis, treatment, and prevention. © 2019 American Physiological Society. Compr Physiol 9:905-931, 2019.

Dietary interventions for cancer survivors

This review evaluates evidence on dietary interventions for cancer survivors giving an overview of people's views and preferences for service attributes and provides a narrative review. After cancer, people often want to change their diet and there is a plethora of evidence why dietary optimisation would be beneficial. However, cancer survivors have different preferences about attributes of services including: place, person and communication mode. Randomised control trials have been reviewed to provide a narrative summary of evidence of dietary interventions. Most studies were on survivors of breast cancer, with a few on colorectal, prostate and gynaecological survivors. Telephone interventions were the most frequently reported means of providing advice and dietitians were most likely to communicate advice. Dietary assessment methods used were FFQ, food diaries and 24-h recalls. Dietary interventions were shown to increase intake of fruit and vegetables, dietary fibre, and improve diet quality in some studies but with contradictory findings in others. Telephone advice increased fruit and vegetable intake primarily in women with breast cancer and at some time points in people after colorectal cancer, but findings were inconsistent. Findings from mail interventions were contradictory, although diet quality improved in some studies. Web-based and group sessions had limited benefits. There is some evidence that dietary interventions improve diet quality and some aspects of nutritional intake in cancer survivors. However, due to contradictory findings between studies and cancer sites, short term follow-up and surrogate endpoints it is difficult to decipher the evidence base.

Lower cutaneous microvascular reactivity in adult cancer patients receiving chemotherapy

Cancer patients with a history of anticancer chemotherapy are at an increased cardiovascular disease risk compared with cancer-free populations. Therefore, we tested the hypothesis that cancer patients receiving adjuvant chemotherapy would have a lower cutaneous microvascular reactivity and lower endothelium-dependent flow-mediated dilation (FMD) of the brachial artery compared with matched cancer-free control subjects. To test this hypothesis, we performed a case control study with seven cancer patients receiving adjuvant chemotherapy and seven matched healthy reference control subjects. Red blood cell flux was measured as an index of cutaneous blood flow via laser Doppler flowmetry. Acetylcholine (ACh)-mediated vasodilation was determined by iontophoresis. Data were expressed as percent increase in cutaneous vascular conductance. Endothelium-dependent FMD of the brachial artery via ultrasonography was determined as an index of macrovessel endothelial function. Cutaneous microvascular reactivity was attenuated in cancer patients compared with control subjects [cancer: 959.9 ± 187.3%, control: 1,556.8 ± 222.2%; P = 0.03, effect size (ES) = 1.1]. Additionally, cancer patients demonstrated a significantly lower area under the curve response to ACh iontophoresis compared with healthy control subjects. Brachial artery FMD was also significantly lower in cancer patients compared with control subjects (cancer: 2.2 ± 0.6%, control: 6.6 ± 1.4%; P = 0.006, ES = 1.6), which was significantly associated with measurements of microvascular reactivity. These findings suggest that decreases in vascular reactivity can occur during cancer chemotherapy, which may have implications for the long-term risk of cardiovascular disease morbidity and mortality. NEW & NOTEWORTHY Cancer survivors treated with chemotherapy experience an increased risk of cardiovascular events, linked to both cardiac and vascular toxicity. The major finding of this study is that microvascular reactivity and macrovascular endothelium-dependent flow-mediated dilation are lower in cancer patients currently receiving adjuvant chemotherapy compared with healthy counterparts.

Long-term and late treatment consequences: endocrine and metabolic effects

PURPOSE OF REVIEW

Cancer therapies often result in the 'late effect of cancer treatment' whereby secondary health complications emerge years after radiotherapy and chemotherapy. This review focuses on endocrine and metabolic consequences in adult cancer survivors as late treatment effects.

RECENT FINDINGS

Endocrine and metabolic disorders are among the most common late effects. Endocrine disorders include hypopituitarism, which leads to growth hormone deficiency, hypogonadism, adrenal insufficiency and hypothyroidism and related clinical manifestations. Hypogonadism in particular is associated with a wide range of health complications requiring input from the like of endocrine and fertility specialists. Immune checkpoint inhibitors are novel anticancer agents, some of which are uniquely associated with hypophysitis which requires early recognition and management, including steroid replacement. Metabolic syndrome, a significant risk for cardiovascular disease, is highly prevalent. Although the effects of cranial irradiation on the hypothalamic-pituitary system are more apparent, the relationship between chemotherapy and endocrine/metabolic disorders remains to be elucidated. There exist published guidelines for monitoring endocrine and cardiometabolic risk in cancer survivors, but the extent of monitoring appears insufficient.

SUMMARY

Regular monitoring and early management of endocrine/metabolic disorders is required to prevent the elevated rates of health complications after cancer treatment, and thereby improve cancer survivorship.

Altered Blood Flow Response to Small Muscle Mass Exercise in Cancer Survivors Treated With Adjuvant Therapy

Background

Adjuvant cancer treatments have been shown to decrease cardiac function. In addition to changes in cardiovascular risk, there are several additional functional consequences including decreases in exercise capacity and increased incidence of cancer‐related fatigue. However, the effects of adjuvant cancer treatment on peripheral vascular function during exercise in cancer survivors have not been well documented. We investigated the vascular responses to exercise in cancer survivors previously treated with adjuvant cancer therapies.

Methods and Results

Peripheral vascular responses were investigated in 11 cancer survivors previously treated with adjuvant cancer therapies (age 58±6 years, 34±30 months from diagnosis) and 9 healthy controls group matched for age, sex, and maximal voluntary contraction. A dynamic handgrip exercise test at 20% maximal voluntary contraction was performed with simultaneous measurements of forearm blood flow and mean arterial pressure. Forearm vascular conductance was calculated from forearm blood flow and mean arterial pressure. Left ventricular ejection time index (LVETi) was derived from the arterial pressure wave form. Forearm blood flow was attenuated in cancer therapies compared to control at 20% maximal voluntary contraction (189.8±53.8 vs 247.9±80.3 mL·min⁻¹, respectively). Forearm vascular conductance was not different between groups at rest or during exercise. Mean arterial pressure response to exercise was attenuated in cancer therapies compared to controls (107.8±10.8 vs 119.2±16.2 mm Hg). LEVTi was lower in cancer therapies compared to controls.

Conclusions

These data suggest an attenuated exercise blood flow response in cancer survivors ≈34 months following adjuvant cancer therapy that may be attributed to an attenuated increase in mean arterial pressure.

Aerobic exercise in anthracycline-induced cardiotoxicity: a systematic review of current evidence and future directions

Cancer and cardiovascular disease are major causes of morbidity and mortality worldwide. Older cancer patients often wrestle with underlying heart disease during cancer therapy, whereas childhood cancer survivors are living long enough to face long-term unintended cardiac consequences of cancer therapies, including anthracyclines. Although effective and widely used, particularly in the pediatric population, anthracycline-related side effects including dose-dependent association with cardiac dysfunction limit their usage. Currently, there is only one United States Food and Drug Administration-approved drug, dexrazoxane, available for the prevention and mitigation of cardiotoxicity related to anthracycline therapy. While aerobic exercise has been shown to reduce cardiovascular complications in multiple diseases, its role as a therapeutic approach to mitigate cardiovascular consequences of cancer therapy is in its infancy. This systematic review aims to summarize how aerobic exercise can help to alleviate unintended cardiotoxic side effects and identify gaps in need of further research. While published work supports the benefits of aerobic exercise, additional clinical investigations are warranted to determine the effects of different exercise modalities, timing, and duration to identify optimal aerobic training regimens for reducing cardiovascular complications, particularly late cardiac effects, in cancer survivors exposed to anthracyclines.

Endovascular Repair of Ruptured Infected Arteries as a Temporizing Measure Versus Destination Therapy

Objective:

Mycotic rupture of the arteries is a rare but deadly disorder. Current management typically involves open surgical repair. However, endovascular repair is a potential treatment that can be used to delay open repair, especially in acutely unstable patients. A case report and review of the literature was conducted to determine whether endovascular therapy could be a destination therapy for patients with arterial rupture secondary to infection.

Methods:

We present the case of a 72-year-old man with a left common iliac artery aneurysm rupture secondary to Salmonella infection treated with endovascular therapy upon initial presentation. A literature review of PubMed yielded 29 patients with ruptured aortic and iliac infected aneurysms that were initially treated with endovascular repair.

Results:

Majority of the patients (76.7%, 23 of 30) were successfully treated with the endovascular treatment and did not require open revision. These patients were often placed on long-term antibiotics.

Conclusion:

The literature review supports endovascular repair with a stent graft as a temporizing measure for infected ruptured arteries in an emergent setting and, in select cases, as a destination therapy.

Influence of Adjuvant Therapy in Cancer Survivors on Endothelial Function and Skeletal Muscle Deoxygenation

The cardiotoxic effects of adjuvant cancer treatments (i.e., chemotherapy and radiation treatment) have been well documented, but the effects on peripheral cardiovascular function are still unclear. We hypothesized that cancer survivors i) would have decreased resting endothelial function; and ii) altered muscle deoxygenation response during moderate intensity cycling exercise compared to cancer-free controls. A total of 8 cancer survivors (~70 months post-treatment) and 9 healthy controls completed a brachial artery FMD test, an index of endothelial-dependent dilation, followed by an incremental exercise test up to the ventilatory threshold (VT) on a cycle ergometer during which pulmonary V˙O2 and changes in near-infrared spectroscopy (NIRS)-derived microvascular tissue oxygenation (TOI), total hemoglobin concentration ([Hb]_total), and muscle deoxygenation ([HHb] ≈ fractional O₂ extraction) were measured. There were no significant differences in age, height, weight, and resting blood pressure between cancer survivors and control participants. Brachial artery FMD was similar between groups (P = 0.98). During exercise at the VT, TOI was similar between groups, but [Hb]_total and [HHb] were significantly decreased in cancer survivors compared to controls (P < 0.01) The rate of change for TOI (ΔTOIΔ/V˙O2) and [HHb] (Δ[HHb]/ΔV˙O2) relative to ΔV˙O2 were decreased in cancer survivors compared to controls (P = 0.02 and P = 0.03 respectively). In cancer survivors, a decreased skeletal muscle microvascular function was observed during moderate intensity cycling exercise. These data suggest that adjuvant cancer therapies have an effect on the integrated relationship between O₂ extraction, V˙O2 and O₂ delivery during exercise.

Health conditions associated with metabolic syndrome after cancer at a young age: A nationwide register-based study

PURPOSE

Childhood cancer survivors are at risk for developing metabolic syndrome (MetS), which subsequently leads to cardiovascular morbidity and excess mortality. Our aim was to investigate the purchases of medications associated with MetS among 7551 early onset cancer patients compared to siblings.

METHODS

Our nationwide Finnish population-based registry study analyzed the drug purchase of medication among early onset cancer patients diagnosed with cancer below the age of 35 years between 1994 and 2004 compared to siblings by linkage to the drug purchase registry, allowing for a maximal follow-up of 18 years.

RESULTS

The hazard ratios (HRs) for purchasing antihypertensives and diabetes drugs were higher after both childhood (HR 4.6, 95%CI 3.1-7.0; HR 3.0, 95%1.5-6.1) and young adulthood (YA) cancer (HR 1.5, 95%CI 1.3-1.8; HR 1.6, 95%CI 1.1-2.2) compared to siblings. The HRs for purchasing lipid-lowering drugs were elevated both after childhood (HR 4.3,95%CI 0.9-19.5) and YA cancer (HR 1.6, 95%CI 1.04-2.5), but only reached significance in YA cancer patients. Among specific cancer diagnosis groups, highest HR values for antihypertensives were found in childhood acute lymphoblastic leukemia (ALL) (HR 6.1, 95%CI 3.7-10.3) and bone tumor (HR 4.3, 95%CI 1.9-9.4), and YA ALL (HR 4.8, 95%CI 3.1-7.0) and acute myeloid leukemia (AML) (HR 3.4, 95%CI 2.5-5.1) patients. Moreover, childhood ALL (HR 6.3, 95%CI 2.7-14.8), AML (HR 7.6, 95%CI 1.9-24.5) and central nervous system (CNS)-tumor (HR 3.5, 95%CI 1.3-9.2) and YA ALL (HR 3.7, 95%CI 1.2-9.5) patients showed the strongest likelihood of purchasing diabetes drugs compared to siblings.

CONCLUSION

The purchase of medications associated with MetS was increased after early onset cancer and highly dependent on the age at cancer diagnosis and the cancer diagnosis. Prevention strategies are imperative for reducing potentially life-threatening cardiovascular complications after early onset cancer.

Risk factors and biomarkers of ischemic stroke in cancer patients

BACKGROUND AND PURPOSE

Stroke is common among cancer patients. However, risk factors and biomarkers of stroke in cancer patients are not well established. This study aimed to investigate risk factors and biomarkers as well as etiology of ischemic stroke in cancer patients.

METHODS

A retrospective review was conducted in cancer patients with ischemic stroke who were admitted to a general hospital in Busan, Korea, between January 2003 and December 2012. The risk factors and biomarkers for stroke and stroke subtypes in cancer patients were compared with age- and sex-matched noncancer patients with ischemic stroke who were admitted to the same hospital during the same period.

RESULTS

One hundred fifty-six cancer patients with ischemic stroke were identified. Cancer patients with ischemic stroke were found to have a significantly lower proportion of hypertension, atrial fibrillation, hyperlipidemia, and ischemic heart disease than noncancer patients with ischemic stroke. However, stroke biomarkers, such as erythrocyte sedimentation rate and high-sensitivity C-reactive protein, fibrinogen, pro-brain natriuretic peptide, and D-dimer levels, were significantly increased in cancer patients with ischemic stroke than in noncancer patients. Large-artery atherosclerosis and stroke of undetermined cause were more common in cancer patients with ischemic stroke than in noncancer patients with ischemic stroke.

CONCLUSIONS

Cancer patients with ischemic stroke showed different risk factors, stroke biomarkers, and stroke etiology compared with noncancer patients with ischemic stroke.

Pilot study of vascular health in survivors of osteosarcoma

BACKGROUND

Cardiovascular-related toxicities have been reported among survivors of osteosarcoma.

METHODS

Fasting blood samples from 24 osteosarcoma survivors were analyzed for high-sensitivity C-reactive protein (hsCRP), triglycerides, total cholesterol, high-density lipoprotein (HDL), apolipoprotein-ß, lipoprotein (a), fibrinogen, circulating endothelial cells (CECs), and surface expression of vascular cell adhesion molecule-1 (VCAM-1). Values were compared to subjects in the natural history Coronary Artery Risk Development in Young Adults (CARDIA) cohort study except for CECs and VCAM-1 expression, which were compared to controls studied at the University of Minnesota Lillehei clinical trials unit.

PROCEDURE

Survivors (54.2% male), median age 18 years (9-32) at diagnosis, 36.5 years (20-56) at evaluation were treated with a variety of chemotherapeutic exposures, all but one were exposed to doxorubicin (median dose 450 mg/m(2) ; range: 90-645 mg/m(2)), 14 (58.3%) received cisplatin, and 3 (12.5%) were exposed to carboplatin. Two survivors (8.3%) received radiation therapy for disease relapse. Compared to CARDIA subjects, mean hsCRP (3.0 mg/L ± 2.0 vs. 1.6 ± 2.3), triglycerides (151 mg/dl ± 81.7 vs. 95.4 ± 101.3), lipoprotein (a) (34.9 mg/dl ± 17.7 vs. 13.8 ± 22.0), and fibrinogen (315.0 mg/dl ± 49.3 vs. 252.4 ± 61.7) were significantly elevated. The number of CECs (0.47 cells/ml ± 2.5 vs. 0.92 ± 2.5) did not differ while surface expression of VCAM-1 (86.4% ± 34.0 vs. 42.1 ± 33.8) was significantly elevated compared to controls.

CONCLUSIONS

Among survivors of osteosarcoma, assessed a median of 14 years from diagnosis, there is evidence of vascular inflammation, dyslipidemia, and early atherogenesis.