From the Journals

Chemotherapy may raise CVD risk in pediatric cancer survivors



Pediatric cancer survivors have a higher likelihood of experiencing a cardiac event, developing diabetes, or having hypertension at a median 10-year follow-up, according to results from a recent research letter published in Circulation.

Ashna Khanna of the University of Toronto and colleagues identified 7,289 pediatric patients in the Pediatric Oncology Group of Ontario Networked Information System who were diagnosed with cancer at median age of 7 years old, who were treated between 1987 and 2010, and who were cancer survivors for 5 years. Each patient was matched to five cancer-free control subjects who were a median of 24 years old at the 10-year follow-up (36,205 cancer-free individuals). The researchers studied whether pediatric cancer survivors experienced cardiac events, such as heart failure, arrhythmia, pericardial disease, valvular disease, or coronary artery disease. They also evaluated the incidence of diabetes and hypertension in each group.

Of the children who survived cancer, 2.8% (n = 203) experienced at least one cardiac event versus 0.9% of controls (P less than .001). The cancer survivors experienced 3.2 cardiac events per 1,000 person-years (95% confidence interval, 2.8-3.6), compared with the control group in which there was a rate of 0.9 cardiac events per 1,000 person-years (95% CI, 0.9-1.9).

With regard to cardiovascular disease (CVD) risk, associated factors included cancer relapse or subsequent cancer (hazard ratio, 1.7; 95% CI, 1.1-2.7) and a 250-mg/m2 or greater dose of doxorubicin-equivalent anthracycline chemotherapy, compared with a dose of less than 250 mg/m2 or no anthracycline chemotherapy (HR, 2.0; 95% CI, 1.4-2.9). Patients who developed diabetes mellitus before a CVD diagnosis were also at higher risk of CVD (HR, 3.0; 95% CI, 1.6-5.8).

Heart failure risk was also statistically significant in patients with relapse and subsequent childhood cancer (HR, 2.0; 95% CI, 1.1-3.7), a 250-mg/m2 or greater dose of doxorubicin-equivalent anthracycline chemotherapy (HR, 8.6; 95% CI, 4.5-16.6), diabetes (HR, 4.3; 95% CI, 1.8-10.7), and hypertension (HR, 3.1; 95% CI, 1.3-7.9).

“While anthracycline chemotherapy may induce heart disease, many patients require this cancer treatment to survive,” Paul Nathan, MD, of the Hospital for Sick Children in Canada and a study coauthor said in a statement. “Doctors should address heart disease risk factors – such as diabetes and hypertension – that can be modified.”

This study was funded in part from a grant by the Canadian Institutes for Health Research. Several authors reported support from noncommercial sources. The other authors reported having no relevant conflicts of interest.

SOURCE: Khanna A et al. Circulation. 2019 Aug 26. doi: 10.1161/CIRCULATIONAHA.119.041403.

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