Heart Disease After Childhood Leukemia - Why?

Anthracyclines for ALL linked to heart disease in some kids

(RxWiki News) Treating childhood cancers usually requires medications, some of which can be toxic to the heart. So will these drugs cause heart problems later on in life?  Recent research asked just that question.

Some children with acute lymphoblastic leukemia (ALL) who are treated with chemotherapy drugs known as anthracylines are more prone to heart disease after treatment. A genetic variation seems to be the reason for this late effect.

Make sure your child's health is monitored closely after cancer treatment.

University of Buffalo associate professor of pharmaceutical sciences, Javier G. Blanco, Ph.D., and colleagues examined how anthracyclines - powerful antibiotics like Adriamycin (doxorubicin) and Daunomycin (daunorubicin hydrochloride)  - break down as a means of finding which children could be vulnerable to heart disease, particularly cardiomyopathy, such as congestive heart failure.

"Anthracyclines are effective drugs used to treat a variety of pediatric cancers, they are also used to treat breast cancer and other malignancies in adults," Blanco explained. These drugs are life savers.

He says children can develop "cardiac toxicity anywhere from one year to more than 15 years after the initial chemotherapy with anthracyclines."

The study involved comparing the DNA of 170 children who'd beaten ALL and later developed anthracycline-related heart disease to the DNA of a control group of 317 survivors without heart disease.

Researchers identified a "tiny gene variant" which was related to the risk of cardiotoxicity. Mice that had higher levels of two enzymes (CBR1 and CBR3) were more prone to heart disease when exposed to low- to moderate doses of anthracyclines.

Further study is needed to validate these findings.

"We have to be careful," says Blanco. "So far, we are showing an association, not yet causation. Our next step will be to conduct a prospective study -- where we don't study individuals who were exposed to anthracyclines in the past but follow them in real time as they are receiving the drug and after."

So what does this mean for children who are taking these medicines?

"If we stop using anthracyclines we will not be able to cure up to 90 percent of the children who suffer from acute lymphoblastic leukemia." Blanco says. "Parents must continue to have their children's health monitored long after the cancer is cured to identify cardiac problems if they develop."

This study was published December, 2011 in the Journal of Clinical Oncology.

The National Institute of General Medical Sciences, the Lance Armstrong Foundation and the Leukemia and Lymphoma Society are among the organizations that funded this research.

Review Date: 
February 10, 2012