Radiation induced lung injury in survivors of childhood cancer

20017

Background: The purpose of this study was to examine survivors of childhood cancer, treated with whole lung irradiation (WLI), for signs of pulmonary insufficiency and to correlate pulmonary function test (PFT) results to symptoms of pulmonary dysfunction as detected using the St. George’s Respiratory Questionnaire (SGRQ). Methods: A cross-sectional study was conducted on eligible patients (>2 years from WLI and <18 years at time of diagnosis) who are followed in our institution’s cancer survivor program. Participating patients had a history and physical examination and PFTs performed pre and post bronchodilator challenge. Patients (or their guardians) also completed the SGRQ. The SGRQ, validated for patients 17 to 80 years, generates four values that define respiratory dysfunction: a Symptoms score, an Activity Score, an Impact score, and a Total score. Results: Twenty eligible patients were identified, 12 of whom consented to participate in this study (11 Wilms, 1 Ewing sarcoma). The median current age was 18.4 years (7.5 to 43 years; n=6 < 14 yrs), while patients received WLI (1,200 cGy n=10, 1500 cGy n=2) at a median age of 4.4 years of age (1.7 to 8.7 years). The median time from radiation therapy was 12.6 years (4.7 to 34.3 years). All patients denied smoking, 4 had a history of asthma and all had a normal lung exam. Ten patients had PFTs, 5 of whom (4/5 adults and 1/5 children) had a restrictive pattern noted by PFTs. One further patient (7.5 yrs of age) had a total lung volume 70% predicted but a forced vital capacity 86% predicted. In the pediatric patients (<14 years currently) the FEF 25–75 (4/5) and SGaw (5/5) were increased following treatment with bronchodilator. Twelve participants completed the SGRQ, 4 had elevated total scores (22, 32, 37 and 64). 1 patient with echocardiographic evidence of a dilated cardiomyopathy had an elevated total score but normal symptom score. One patient with a recorded acute pneumonitis after WLI, now 18 years later had normal PFTs and normal SGRQ scores. No correlation was seen between PFT results and SGRQ scores. Conclusions: A restrictive lung function pattern is more common at a later age following WLI in childhood. Mid-expiratory flow and airway conductance following bronchodilator were increased in children. The functional significance of these findings requires further study.

No significant financial relationships to disclose.

Long-term cardiac outcomes following low-dose anthracycline exposure

9519

Background: Pediatric cancer survivors treated with moderate-high dose (=250mg/m2) anthracycline therapy are known to be at risk for cardiac toxicity. It remains unclear what cardiac risk exists for survivors who received a low dose (<250mg/m2) therapy. Methods: Cardiac MRI and maximal VO2max testing were performed on young adult survivors of childhood acute lymphoblastic leukemia (ALL). MRI measurements included ejection fraction (EF), left ventricular (LV) mass, end diastolic volume (EDV), end systolic volume (ESV), and concentricity (LV mass/EDV). Survivors who were treated with low dose anthracycline (< 250mg/m2) were compared to those without anthracycline exposure. Spearman correlations and multivariable linear regression were used to examine the relationship between anthracycline dose and measures of cardiac function and cardiorespiratory fitness. Results: Sixty-seven survivors (mean age 23.9 ±5 years) participated, including 39 (58.2%) females. The mean interval from cancer diagnosis to study was 17.4 ± 6.6 years. The number of participants by cumulative anthracycline dose were 19 (28.4%) with no exposure, 28 (41.8%) with doses of 1–249mg/m2, and 20 (29.8%) with doses of =250mg/m2. When adjusted for age and race, there was not a significant difference in the cardiac MRI outcomes and VO2max levels between participants who received 1- 249mg/m2 of anthracycline versus those without anthracycline exposure. Conclusions: With continued use of anthracyclines at cumulative low doses, particularly in ALL standard risk trials, it is important to determine if there is a long-term cardiotoxicity. With a mean follow-up of 17 years, our data support the safety of low cumulative dose anthracycline.

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No significant financial relationships to disclose.

Evaluation for cardiac toxicity with MRI in young adult survivors of acute lymphoblastic leukemia (ALL)

18604

Background: Long-term survivors of childhood cancer treated with a moderate to high cumulative dose (≥300mg/m2) an anthracycline are known to be at risk for cardiac toxicity. It remains unclear what cardiac risk exists for survivors who received a low cumulative dose (<300mg/m2) of an anthracycline. Methods: We are conducting an NIH sponsored trial in 120 young adult survivors of ALL to determine the prevalence of cardiovascular risk factors and to determine the effectiveness of an exercise intervention. As part of their cardiovascular risk assessment, participants undergo cardiac MRI, a tool with excellent reproducibility in assessing left ventricular (LV) size and function. The aim of this component of the study is to determine the prevalence of cardiac toxicity in survivors treated with low dose anthracycline in comparison to those who did not receive any anthracycline. Descriptive statistics, chi-square analysis, and spearman correlation coefficients were used to examine the relationship between anthracycline dose and measures of cardiac function. Results: This study represents a work in progress. Preliminary results from the first 22 participants who have had a cardiac MRI do not show a significant difference in ejection fraction, LV mass, cardiac output, or mass to volume ratio between those treated with low cumulative dose anthracycline versus no anthracycline. Available cardiac MRI data for all participants will be presented at the meeting. Conclusions: With the continued use of an anthracycline at cumulative low doses, particularly in upcoming ALL standard risk trials, it is particularly important to determine if there is a risk of cardiac toxicity after low doses with aging.

No significant financial relationships to disclose.