By Linda Carroll
(Reuters Health) - Childhood cancer survivors' risks forheart problems may be broader than what was previouslyrecognized, researchers say.
It's been known for years that some treatments for childhoodcancer increase the risk of heart failure. But in a new study ofmore than 43,000 children, Canadian researchers found youngcancer survivors had as much as a three-fold increased risk ofdeveloping a variety of other cardiovascular problems, too,according to the report published in Circulation.
The new findings suggest that survivors of childhood cancersshould focus on improving modifiable heart disease risk factors,such as high blood pressure and diabetes, said study coauthorDr. Paul Nathan, a professor of pediatrics and health policy,management and evaluation at the University of Toronto and astaff oncologist at The Hospital for Sick Children.
There's a chance that there will be new cancer treatmentsthat are less toxic to the heart, Nathan said.
"However, we can't eliminate use of these (cardio-toxic)treatments completely because they are needed to cure cancer,"Nathan said in an email. So, it's important to make "suresurvivors and their doctors are aware of the risks and (know)what to look out for."
The heightened risks also mean that childhood cancersurvivors should be screened for heart disease so it can becaught early, Nathan said.
To take a closer look at the impact of childhood cancertherapies on the heart, Nathan and his colleagues turned to apediatric cancer registry called the Pediatric Oncology Group ofOntario Networked Information System, along with health datafrom the general public collected by The Institute for ClinicalEvaluative Sciences (ICES) a nonprofit corporation.
The researchers focused on the 7,289 cancer survivors whohad been diagnosed before age 18, treated at a pediatric cancercenter between 1987 and 2010, and survived at least 5 years.Each of those survivors was matched in age, gender and postalcode to 5 cancer-free individuals from the general population,for a total of 36,205 individuals in the control group.
Half of the patients were tracked for more than 10 years.During follow-up, 203 survivors (2.8%) experienced one or morecardiac events as compared to 331 of those in the control group(0.9%).
When the researchers analyzed their data, they found thateven at relatively young ages, cancer survivors had a three-foldincreased risk for any type of heart event and as much as aten-fold increased risk for heart failure compared to theirpeers.
Childhood cancer survivors also appeared to be at increasedrisk of metabolic conditions such as diabetes, hypertension andhigh cholesterol. And those conditions increased the risk ofheart disease.
Cancer survivors diagnosed with diabetes were more thanthree times more likely to develop cardiovascular disease andmore than 4 times more likely to develop heart failure comparedwith nondiabetic survivors. Similarly, those diagnosed with highblood pressure were 3 times more likely to develop heart failurecompared to non-hypertensive survivors.
This study is a useful reminder to not overlook traditionalrisk factors and more common types of cardiovascular disease inchildhood cancer survivors, said Dr. Prashant Vaishnava, acardiologist at The Mount Sinai Hospital in New York City. "Thisis becoming a recurring theme in medicine as patients are ableto survive diseases that once may have been quickly fatal. Thetreatment paradigm for these survivors shifts to management ofthose conditions which are ubiquitous in the generalpopulation."
These days many pediatric cancer centers follow survivors ofchildhood cancers for possible heart damage, said Dr. KirstenRose-Felker, a pediatric cardiologist at UPMC Children'sHospital of Pittsburgh.
While many will just need to be monitored for the rest oftheir lives, some children suffer severe damage to their heartsfrom the cancer treatments, Rose-Felker said. "We've taken careof patients who needed a heart transplant," she added. "Thedamage can be so bad that it completely destroys the heartmuscle."
The number of children who will need to be watched for heartproblems is on the rise, Rose-Felker said. "There are half amillion childhood cancer survivors in the U.S. and that numbercontinues to grow as treatments get better," she added.
The good news, Rose-Felker said, is that this is "somethingwe can actually affect."
SOURCE: http://bit.ly/344iA04 Circulation, online August 26,2019.