Prevalence of carotid ultrasound screening in survivors of childhood cancer: A report from the Childhood Cancer Survivor Study

Introduction: Many childhood cancer survivors are at risk for cardiovascular disease and stroke. The North American Children's Oncology Group long-term follow-up guidelines recommend carotid ultrasound in cancer survivors 10 years after neck radiation therapy (RT) ≥40 Gy. The use of carotid ultrasound in this population has not been described.

Methods: Survivors of childhood cancer diagnosed 1970-1999 (N = 8693) and siblings (N = 1989) enrolled in the Childhood Cancer Survivor Study were asked if they had ever had a carotid ultrasound. Prevalence of carotid ultrasound was evaluated. Prevalence ratios (PR) and 95% confidence intervals (CIs) were evaluated in multivariate Poisson regression models.

Results: Among participants with no reported cardiovascular condition, prevalence of carotid ultrasound among survivors with RT ≥40 Gy to the neck (N = 172) was 29.7% (95% CI, 22.5-36.8), significantly higher than those with <40 Gy (prevalence 10.7%; 95% CI, 9.9%-11.4%). Siblings without a cardiovascular condition (N = 1621) had the lowest prevalence of carotid ultrasound (4.7%; 95% CI, 3.6%-5.7%). In a multivariable models among survivors with no reported cardiovascular condition and RT ≥40 Gy to the neck, those who were over age 50 (vs. 18-49) at follow-up (PR = 1.82; 95% CI, 1.09-3.05), with a history of seeing a cancer specialist in the last 2 years (PR = 2.58; 95% CI, 1.53-4.33), or having a colonoscopy (PR = 2.02; 95% CI, 1.17-3.48) or echocardiogram (PR = 6.42; 95% CI, 1.54-26.85) were more likely to have had a carotid ultrasound.

Conclusion: Many survivors do not undergo carotid ultrasound despite meeting existing guidelines. Health care delivery features such as having seen a cancer specialist or having other testing are relevant.