|The following article features coverage from the 2017 American Society of Clinical Oncology Annual Meeting in Chicago, Illinois. Click here to read more of Oncology Nurse Advisor‘s conference coverage.|
CHICAGO — Cardiac radiotherapy at doses of 10 Gy or higher increases cardiovascular disease (CVD) risk in a dose-dependent manner among long-term survivors of pediatric cancer, investigators reported at the 2017 American Society for Clinical Oncology (ASCO) Annual Meeting.
In addition, young children are at higher risk for CVD after low-dose (less than 10 Gy) cardiac radiotherapy (CRT) or high-dose anthracycline exposure.
“The implications for this research are broad,” said lead investigator James E. Bates, MD, of the University of Florida. “The increased risk for cardiac disease among young children treated with less than 10 Gy of RT [radiotherapy] suggests that optimization of radiotherapy technique to minimize cardiac exposure is important in these patients. Additionally, the increased risk of cardiac disease among young children treated with high-dose anthracyclines emphasizes the importance of long-term screening in survivors of pediatric cancer treated at a young age.”
Dr Bates and collaborators evaluated Common Terminology Criteria for Adverse Events (CTCAE) grade 3-5 CVD events occurring 5 or more years after diagnosis in a group of 23,465 5-year survivors of pediatric cancer diagnosed in 1970 to 1999. The patients were part of the Childhood Cancer Survivor Study. At a median age of 28.4 years (range 5.6 to 58.3 years) and follow-up of 20.2 years (range 5 years to 39.3 years), 239 coronary artery disease (CAD) and 359 heart failure (HF) events occurred. The cumulative incidence of CVD, CAD, and HF were 4.8% (95% CI, 4.3-5.3), 2.4% (95% CI, 2.2-2.9), and 2.5% (95% CI, 2.2-2.9), respectively, by 30 years from diagnosis.
At mean CRT doses of 10 Gy or higher, increasing doses were associated with a progressively increasing risk of CVD. A CRT dose of at least 10 but less than 20 Gy was associated with a 3.6-fold increased risk of CVD compared with those not receiving CRT (95% CI, 2.1-6.2; P <.01). A dose of at least 20 but less than 30 Gy was associated with a 4.4-fold increased risk (95% CI, 2.7-7.2, P <.01). A dose of 30 Gy or higher was associated with a 7.5-fold increased risk (95% CI, 4.9-11.5; P <.01).
Among patients receiving a low mean CRT dose (0.1 to less than 10 Gy), younger children had higher rates of CVD. Compared with patients older than 13 years, those aged 4 years or younger had a 2.2-fold increased risk of CVD (95% CI 1.0-4.6; P =.04); patients older than 4 year but not older than 13 years had a 2.1-fold increased risk (95% CI 1.1–4.1; P =.03).
Additionally, among survivors exposed to anthracycline doses of 250 mg/m2 or higher, those aged 4 years or younger at diagnosis had 4.9-fold increased risk of CAD (95% CI, 1.5-16.3; P =.01) and a 3-fold increased risk of HF (95% CI 1.6–5.0; P <.01).
Exposure to cisplatin doses of 300 mg/m2 or higher was associated with an 80% increased risk of any CVD (95% CI 1.2–2.6; P <.01), primarily attributable to an increased risk of HF, Dr Bates’ team reported.
Read more of Oncology Nurse Advisor‘s coverage of the 2017 American Society of Clinical Oncology Annual Meeting by visiting the conference page.
1. Bates JE, Liu Q, Yasui Y, et al. Age-associated vulnerability to treatment-related late cardiotoxicity: a report from the Childhood Cancer Survivor Study (CCSS). Oral presentation at: 2017 American Society of Clinical Oncology Annual Meeting; June 2-6, 2017; Chicago, IL.