Prevalence of cardiovascular late sequelae in long-term survivors of childhood cancer: A systematic review and meta-analysis

BACKGROUND: Cardiovascular diseases are well-known late effects of childhood cancer and research on these late effects is a highly important emerging field. We conducted a systematic review with a meta-analysis to give an overview of the current evidence and the prevalence of late cardiovascular events. PROCEDURE: We included publications in which the study populations were children and adolescents who survived cancer. Outcome was defined as all cardiovascular clinical and subclinical endpoints or diagnoses appearing at least one year after cancer diagnosis. A systematic overview is presented for all included studies. A quantitative meta-analysis was conducted for hypertension and stroke. RESULTS: Sixty-four papers were included in the review. The age range at cancer diagnosis was 0-24 years; age at the end of follow-up ranged from 7 to 71 years. Prevalence of cardiovascular late effects varied from 0% for stroke up to 70% for subclinical hypertension. Large heterogeneity was found regarding study size, study design, definition of endpoints, and investigation/examination method. The weighted average prevalence was 19.7% for hypertension and 2.3% for stroke. As no specific results for gender, cancer therapy, or age at cancer diagnosis were present in most papers, a detailed comparison and pooled analysis was difficult. CONCLUSION: This review showed the vast range of cardiovascular late effects after childhood or adolescent cancer therapy. The differences between the papers prevented drawing a conclusive picture of the prevalence of cardiovascular late effects. Large cohort studies and better reporting are needed to improve the knowledge on this topic.