Study Finds Cardiovascular Disease Is Prevalent and Often Asymptomatic in Childhood Cancer Survivors
Although historically the leading cause of death among survivors of childhood cancer has been cancer recurrence, adverse late effects of cancer therapy have become the leading cause of death 30 years after diagnosis, and those deaths are frequently attributed to premature cardiovascular disease, according to a study by Mulrooney et al. The study assessed cardiac outcomes among survivors of childhood cancer and found evidence of cardiomyopathies, conduction or rhythm abnormalities, and coronary artery and valvular diseases in large numbers of adult survivors of childhood cancer who were exposed to cardiotoxic therapies. Because the patients were young for such cardiovascular abnormalities and asymptomatic, prospective studies are needed to assess the value of screening for such abnormalities in adult survivors of childhood cancer, concluded the researchers. The study was published in the Annals of Internal Medicine.
Study Methodology
The researchers analyzed data from 1,853 adult survivors of childhood cancer. The study participants completed a baseline evaluation in the St. Jude Lifetime Cohort Study (SJLIFE), an ongoing study designed to facilitate longitudinal evaluation of health outcomes among adults who previously received treatment for childhood cancer. To be enrolled in the cohort, participants must have been diagnosed with cancer and treated at St. Jude Children’s Research Hospital, be 18 years or older, and have survived 10 years or more after diagnosis. Participants must have been treated with cardiotoxic therapy, including anthracycline chemotherapy or cardiac-directed radiation therapy.
The survivors completed a detailed health questionnaire and had a medical evaluation based on the Children’s Oncology Group’s Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers. Assessments included a history and physical examination, fasting laboratory testing, echocardiography and electrocardiography, and a 6-minute walk test.
Study Findings
One-half of the survivors (52.3%) were men with a median age of 8 years (range = 0–24 years) at cancer diagnosis and 31 years (range = 18–60 years) at evaluation. Cardiomyopathy was present in 7.4% survivors (newly identified at the time of evaluation in 4.7%); coronary artery disease in 3.8% (newly identified in 2.2%); valvular regurgitation or stenosis in 28.0% (newly identified in 24.8%); and conduction or rhythm abnormalities in 4.4% (newly identified in 1.4%). Nearly all survivors were asymptomatic.
The prevalence of cardiac conditions increased with age at evaluation, ranging from 3% to 24% among survivors aged 30 to 39 years to 10% to 37% among those aged 40 years or older. In multivariable analysis, survivors exposed to anthracycline doses of 250 mg/m2 or more had greater odds of cardiomyopathy (odds ratio [OR] = 2.7; 95% confidence interval [CI] = 1.1–6.9) than those who were not exposed. Survivors exposed to heart radiation also had increased odds of cardiomyopathy (OR = 1.9; 95% CI = 1.1–3.7) compared with those who were not exposed. Radiation exposure greater than 1,500 cGy with any anthracycline exposure conferred the greatest odds for valve findings.
Conclusion
“We identified considerable cardiovascular disease in this large cohort of adult survivors of childhood cancer,” wrote the study authors. “The prevalence is inconsistent with the chronological age of the population and suggests a substantial future health-care burden. Clinically, these data may guide stratification of risk factors, screening practices, health counseling, and potential therapeutic measures aimed at changing the disease trajectory in this young adult population.”
Daniel Mulrooney, MD, MS, of St. Jude Children’s Research Hospital, is the corresponding author of this study.
Funding for this study was provided by the National Cancer Institute and the American Lebanese Syrian Associated Charities.
Author disclosure forms can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=M15-0424.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
