Photo by Bill Branson
A new study has provided additional insight into the development of cardiac abnormalities in adult survivors of childhood cancer.
Researchers analyzed more than 1800 cancer survivors who were exposed to cardiotoxic therapies as children.
The team said they found evidence of cardiac abnormalities in a substantial number of these subjects, many of whom were younger and did not exhibit symptoms of abnormalities.
Daniel A. Mulrooney, MD, of St. Jude Children’s Research Hospital in Memphis, Tennessee, and his colleagues reported these findings in Annals of Internal Medicine.
The team assessed cardiac outcomes among 1853 subjects who were 18 and older and had received cancer-related cardiotoxic therapy at least 10 years earlier.
The subjects were pretty evenly split along gender lines (52.3% male), their median age at cancer diagnosis was 8 (range, 0 to 24), and their median age at evaluation was 31 (range, 18 to 60).
At evaluation, 7.4% of subjects had cardiomyopathy (newly identified in 4.7%), 3.8% had coronary artery disease (newly identified in 2.2%), 28% had valvular regurgitation or stenosis (newly identified in 24.8%), and 4.4% had conduction or rhythm abnormalities (newly identified in 1.4%). All but 5 subjects were asymptomatic.
Multivariable analysis suggested the odds of developing cardiomyopathy were significantly associated with being male (odds ratio [OR]=1.9), receiving anthracycline doses of 250 mg/m2 or greater (OR=2.7), having cardiac radiation exposure greater than 1500 cGy (OR=1.9), and having hypertension (OR=3.0).
Being younger at diagnosis was associated with higher odds of valvular disease. The ORs were 1.5 for patients who were 0 to 4 years of age at diagnosis and 1.3 for patients who were 5 to 9 at diagnosis.
Receiving higher radiation doses was associated with higher odds of valvular disease as well. But associations between radiation and valvular disease varied according to a patient’s anthracycline exposure (interaction P<0.001). The highest odds were among survivors with the highest doses of radiation exposure and any anthracycline exposure (OR=4.5).
The researchers also noted a reduction in the OR for valvular disease among obese patients (OR=0.4) and those with dyslipidemia (OR=0.7).
The team said there were not enough cases of coronary artery disease and conduction or rhythm abnormalities to support a fully adjusted multivariable model. However, it seemed these outcomes were more common with older age (≥40 years) and among patients with cardiac radiation doses of 1500 cGy or greater.
The researchers said this study revealed “considerable cardiovascular disease” in a large cohort of adult survivors of childhood cancer, which suggests a substantial future healthcare burden.
The team believes their findings could guide stratification of risk factors, screening practices, health counseling, and potential therapeutic measures aimed at changing the disease trajectory in this young adult population.
