Current recommendations for cardiac assessment could reduce the incidence of congestive heart failure (CHF) in childhood cancer survivors but less frequent assessment could also be more cost-effective, according to two studies published in the Annals of Internal Medicine on May 19.
Increased risk for cardiovascular events is a major concern for childhood cancer survivors, particularly those who were treated with cardiotoxic therapies. “At 30 to 40 years after the initial cancer diagnosis, the cumulative incidence of cardiac disease among adult childhood cancer survivors is considerably greater than that of the U.S. general population, ranging from 7.2 percent and 12.4 percent, and CHF is responsible for as many as one half of cases,” wrote Jennifer M. Yeh, PhD, of the Harvard School of Public Health in Boston, and colleagues.
The Children’s Oncology Group dictates that routine cardiac surveillance with echocardiography be used in childhood cancer survivors in their follow-up guidelines. However, performance characteristics of echocardiography to detect asymptomatic left ventricular dysfunction (ALVD) in this population is lacking and clinical studies regarding the effectiveness of angiotensin-converting enzyme (ACE) inhibitors and β-blockers (BBs) to reduce systolic CHF risk among childhood cancer survivors are inconclusive. Although consensus-based guidelines on cardiac assessment can offer guidance for pediatric oncology survivors, their influence on long-term outcomes is not clear. In the first study, Yeh and colleagues aimed to investigate the clinical benefits and cost-effectiveness of routine cardiac assessment to detect ALVD and of ACE and inhibitor and BB treatment to reduce systolic CHF incidence and improve overall survival. Utilizing a mathematical model, the researchers compared risks for systolic congestive heart failure, quality-adjusted life years and total costs of different screening intervals applied to a hypothetical population of five-year childhood cancer survivors who were originally diagnosed at age ten.
The study’s results revealed that the lifetime risk for systolic CHF among five-year pediatric cancer survivors at age 15 was 18.8 percent without routine cardiac assessment, with an average age of onset at 58.8 years. Routine echocardiography reduced lifetime risk for CHF by 2.3 percent with assessment every 10 years to 8.7 percent with annual assessment. The incremental cost-effectiveness ratio (ICER) for assessment every ten years was $111,600 per quality-adjusted life-year (QALY) compared with no assessment. Assessment every five years had an ICER of $117,900 per QALY, and ICERs for more frequent assessment surpassed $165,000 per QALY.
“Although further analysis of the effects of radiation dose on ALVD will be needed, our model suggests that cardiac radiation would have to increase the relative AER for CHF by more than 75 percent for routine assessment every 2 years to be cost-effective for the low-dose anthracycline subgroup, an increase that has not been seen,” wrote Yeh et al. They concluded that less frequent screening than is currently recommended may be preferred, and suggest a possible revision of current recommendations.
The other study released by the Annals of Internal Medicine on May 19, led by F. Lennie Wong, PhD, of the City of Hope in Duarte, Calif., and colleagues, similarly evaluated the efficacy and cost-effectiveness of the Children’s Oncology Group guidelines for childhood cancer survivors to undergo lifetime echocardiographic screening for ALVD. The researchers used mathematical models to compare lifetime costs, quality-adjusted life-years and total risks for heart failure for different screening intervals versus no screening of a hypothetical population of five-year childhood cancer survivors. Screening frequencies differed according to 12 risk profiles that were based on age at diagnosis, total anthracycline dose and history of chest irradiation.
The results indicated that the Children’s Oncology Group Guidelines versus no screening had an ICER of $61,500, extended life expectancy by six month and QALYs by 1.6 months, and reduced the cumulative incidence of heart failure by 18 percent at 30 years after cancer diagnosis. Less frequent screenings (changing from every one, two, or five year screenings to two to four, five, and ten year intervals), however, are more cost-effective than the guidelines and maintain 80 percent of the health benefits.
“A more cost-effective strategy involving less frequent screening, and hence less patient burden, could provide similar health beneﬁts at half of the cost,” wrote Wong and colleagues. In an associated editorial by Richard M. Steingart, MD, of the Memorial Sloan Kettering Cancer Center in New York City, and colleagues, the authors wrote: “Reading these studies side by side advances our understanding of this population and illustrates the importance and complexity of an effective screening strategy. It also serves as an example of how two experienced groups can apply different assumptions and variables in their respective models and still arrive at broadly similar conclusions: Although application of the Children’s Oncology Group Long-Term Follow-Up Guidelines for Survivors of Childhood, Adolescent, and Young Adult Cancers recommendations can reduce the CHF risk, there may be more cost-effective strategies.”