INTRODUCTION
The burden of cancer and atrial fibrillation (AF) remains significant in the United States. While cancer mortality has declined over the past three decades, projections estimate over two million new cancer cases and approximately 600,000 associated deaths in 2024, alongside a rising AF prevalence expected to affect 12.1 million Americans by 2030.1,2 A bidirectional relationship exists between these conditions, with cancer patients experiencing a heightened risk of AF due to factors such as pro-inflammatory immune activation, post-surgical inflammatory responses, and cardiotoxic effects of chemotherapy and radiotherapy.3 Studies suggest a 47% increased AF risk in cancer patients overall and a 20% increased risk in those not actively undergoing cancer treatment.4,5Conversely, AF may elevate cancer risk by disrupting apoptosis, potentially favoring carcinogenesis. The co-occurrence of AF and cancer compounds mortality risk, increasing the likelihood of thromboembolism and a six-fold increased risk of heart failure.6Despite well-documented independent mortality trends for cancer and AF, mortality trends in individuals with concomitant diagnoses are lacking. To address this gap, we analyzed Centers for Disease Control and Prevention’s Wide-ranging Online Data for Epidemiologic Research (CDC WONDER) dataset to evaluate trends in cancer- and AF-related mortality over the past two decades, stratified by gender and race/ethnicity.