Cardiovascular status of childhood cancer survivors exposed and unexposed to cardiotoxic therapy.

PURPOSE: To determine whether cardiovascular abnormalities in childhood cancer survivors are restricted to patients exposed to cardiotoxic anthracyclines and cardiac irradiation and how risk factors for atherosclerotic disease and systemic inflammation contribute to global cardiovascular status. METHODS: We assessed echocardiographic characteristics and atherosclerotic disease risk in 201 survivors of childhood cancer with and without exposure to cardiotoxic treatments at a median of 11 years after diagnosis (range, 3 to 32 years) and in 76 sibling controls. RESULTS: The 156 exposed survivors had below normal left ventricular (LV) mass, wall thickness, contractility, and fractional shortening and above normal LV afterload. The 45 unexposed survivors also had below normal LV mass overall, and females had below normal LV wall thickness. Exposed and unexposed survivors, compared with siblings, had higher levels of N-terminal pro-brain natriuretic peptide (81.7 and 69.0 pg/mL, respectively, v 39.4 pg/mL), higher mean fasting serum levels of non-high-density lipoprotein cholesterol (126.5 and 121.1 mg/dL, respectively, v 109.8 mg/dL), higher insulin levels (10.4 and 10.5 µU/mL, respectively, v 8.2 µU/mL), and higher levels of high-sensitivity C-reactive protein (2.7 and 3.1 mg/L, respectively, v 0.9 mg/L; P < .001 for all comparisons). Age-adjusted, predicted-to-ideal 30-year risk of myocardial infarction, stroke, or coronary death was also higher for exposed and unexposed survivors compared with siblings (2.16 and 2.12, respectively, v 1.70; P < .01 for both comparisons). CONCLUSION: Childhood cancer survivors not receiving cardiotoxic treatments nevertheless have cardiovascular abnormalities, systemic inflammation, and an increased risk of atherosclerotic disease. Survivorship guidelines should address cardiovascular concerns, including the risk of atherosclerotic disease and systemic inflammation, in exposed and unexposed survivors.

Aggregating traditional cardiovascular disease risk factors to assess the cardiometabolic health of childhood cancer survivors: an analysis from the Cardiac Risk Factors in Childhood Cancer Survivors Study.

BACKGROUND: Childhood cancer survivors are at increased risk of cardiovascular disease (CVD), which may be associated with traditional CVD risk factors. We used CVD risk aggregation instruments to describe survivor cardiometabolic health and compared their results with sibling controls. METHODS: Traditional CVD risk factors measured in 110 survivors and 31 sibling controls between 15 and 39 years old were aggregated using Pathobiological Determinants of Atherosclerosis in Youth (PDAY) scores and the Framingham Risk Calculator (FRC) and expressed as ratios. The PDAY odds ratio represents the increased odds of currently having an advanced coronary artery lesion, and the FRC risk ratio represents the increased risk of having a myocardial infarction, stroke, or coronary death in the next 30 years. Ratios are relative to an individual of similar age and sex without CVD risk factors. RESULTS: The median PDAY odds ratio for survivors was 2.2 (interquartile range 1.3-3.3), with 17% >4. The median FRC risk ratio was 1.7 (interquartile range 1.0-2.0), with 12% >4. Survivors and siblings had similar mean PDAY odds ratios (2.33 vs 2.29, P = .86) and FRC risk ratios (1.72 vs 1.53, P = .24). Cancer type and treatments were not associated with cardiometabolic health. There was a suggested association for physical inactivity with PDAY odds ratios (r = 0.17, P = .10) and FRC risk ratios (r = 0.19, P = .12). CONCLUSIONS: Cardiometabolic health is poor in childhood cancer survivors but not different than that of their siblings, highlighting the importance of managing traditional CVD risk factors and considering novel exposures in survivors.

Characteristics and determinants of adiposity in pediatric cancer survivors.

BACKGROUND: Adiposity and the diseases associated with it, including cardiovascular disease, are emerging long-term complications of pediatric cancer survivors. Direct evaluations of adiposity and comparisons to contemporary controls that can differentiate recent trends in obesity from cancer-related treatments and sequelae are limited. METHODS: We evaluated demographic, treatment, lifestyle, and endocrine factors at the time of dual-energy X-ray absorptiometry testing in 170 non-Hispanic white survivors and 71 sibling controls, and compared three measures of adiposity [body mass index (BMI), total body fat, and trunk fat]. For the survivors alone, we determined factors independently associated with BMI and body fat. RESULTS: Survivors were at 12 years since diagnosis; 58% had leukemia or lymphoma. BMI did not differ between groups. Among males, body fat was greater in survivors than in controls (25.8% versus 20.7%; P = 0.007), as was trunk fat (26.7% versus 21.3%; P = 0.008). Total or trunk fat did not differ among females. Cholesterol, triglycerides, low-density lipoprotein cholesterol, and television viewing hours were higher among male survivors than in controls. Independent factors associated with higher BMI and total and trunk fat included any cranial radiation and television viewing hours, whereas prior treatment with cyclophosphamide was associated with lower BMI and body fat measures. CONCLUSIONS: Compared with siblings, male survivors have greater body fat and metabolic risks. Cranial irradiation and television hours are important risk factors for adiposity in pediatric cancer survivors. IMPACT: Pediatric cancer survivors should be carefully monitored for cardiovascular risk factors and sedentary lifestyles.

A clinic-based, comprehensive care model for studying late effects in long-term survivors of pediatric illnesses.

OBJECTIVE: Long-term survivors of several childhood illnesses are at risk for multiple late effects of their illness or therapy, and children with documented toxic exposures may also experience long-term health consequences. Clinical studies of these effects are difficult to conduct. The Cardiovascular Status in Childhood Cancer Survivors Study is an established study that highlights the ability to perform comprehensive clinical investigations when patients are cared for in a formal, long-term follow-up clinic. This clinic model facilitates long-term retention and recruitment of patients, allowing comprehensive clinical studies of late effects of illness or exposures, in this case, of cardiovascular complications of cancer treatment during childhood. METHODS: The study is funded through the National Institute of Health Office of Cancer Survivorship. Participants are recruited from the Long-Term Survivors Clinic at the University of Rochester. The clinic provides care for all survivors of childhood cancer in the region. The Long-Term Survivors Clinic provides medical care and psychosocial and educational support to patients and facilitates coordination of care. Patients remain in close contact with clinic staff for extended periods. RESULTS: We recruited a representative sample of this long-term survivor population, with a wide range of ages, diagnoses, and time since diagnosis. Longitudinal collection of detailed clinical data will enable us to conduct cohort studies of late effects as well as case-control studies of toxic exposures. CONCLUSIONS: The success of this study shows the advantages of formal programs for continued care of patients with chronic illnesses or treatment or toxic exposures. The Long-Term Survivors Clinic provides an excellent model for clinical care and research that is applicable to multiple pediatric and young adult populations.

Magnetic resonance spectroscopic imaging of tumor metabolic markers for cancer diagnosis, metabolic phenotyping, and characterization of tumor microenvironment.

Cancer cells display heterogeneous genetic characteristics, depending on the tumor dynamic microenvironment. Abnormal tumor vasculature and poor tissue oxygenation generate a fraction of hypoxic tumor cells that have selective advantages in metastasis and invasion and often resist chemo- and radiation therapies. The genetic alterations acquired by tumors modify their biochemical pathways, which results in abnormal tumor metabolism. An elevation in glycolysis known as the "Warburg effect" and changes in lipid synthesis and oxidation occur. Magnetic resonance spectroscopy (MRS) has been used to study tumor metabolism in preclinical animal models and in clinical research on human breast, brain, and prostate cancers. This technique can identify specific genetic and metabolic changes that occur in malignant tumors. Therefore, the metabolic markers, detectable by MRS, not only provide information on biochemical changes but also define different metabolic tumor phenotypes. When combined with the contrast-enhanced Magnetic Resonance Imaging (MRI), which has a high sensitivity for cancer diagnosis, in vivo magnetic resonance spectroscopic imaging (MRSI) improves the diagnostic specificity of malignant human cancers and is becoming an important clinical tool for cancer management and care. This article reviews the MRSI techniques as molecular imaging methods to detect and quantify metabolic changes in various tumor tissue types, especially in extracranial tumor tissues that contain high concentrations of fat. MRI/MRSI methods have been used to characterize tumor microenvironments in terms of blood volume and vessel permeability. Measurements of tissue oxygenation and glycolytic rates by MRS also are described to illustrate the capability of the MR technology in probing molecular information non-invasively in tumor tissues and its important potential for studying molecular mechanisms of human cancers in physiological conditions.