Cardiovascular Disease and Cancer: A Reciprocal Relationship

Cardiovascular disease and cancer are leading causes of morbidity and mortality globally.¹ Historically, these conditions have been managed as distinct entities; however, a growing body of evidence highlights a significant bidirectional relationship. This relationship is characterised by shared risk factors, including age, obesity, diabetes, hypertension, dyslipidaemia, and smoking.^1,2 Furthermore, advancements in cancer therapies, while improving survival, have introduced cardiovascular toxicities, leading to a new subspecialty of cardio-oncology.³ Conversely, patients with pre-existing cardiovascular conditions may experience altered cancer prognosis or increased susceptibility to treatment side effects.²

The Reciprocal Relationship

The mechanisms underpinning the reciprocal relationship between CVD and cancer are multifaceted. Chronic inflammation, a common feature in both conditions, contributes to disease progression.⁴ For example, systemic inflammation associated with certain cancers can accelerate atherosclerotic processes.⁴ Similarly, traditional cardiovascular risk factors, such as obesity and type 2 diabetes, are independently associated with an increased risk of developing various cancers.⁵

Cancer treatments represent a significant contributor to cardiovascular morbidity. Anthracyclines, a class of chemotherapy agents, are well-known for their dose-dependent cardiotoxicity, which can manifest as left ventricular dysfunction and heart failure.⁶ Trastuzumab, a human epidermal growth factor receptor 2 (HER2) inhibitor, is associated with a risk of cardiac dysfunction, particularly when administered concurrently with anthracyclines.⁷ Newer targeted therapies, such as tyrosine kinase inhibitors (TKIs), can induce hypertension, QT prolongation, and arterial thromboembolism.⁸ Immunotherapy agents, including immune checkpoint inhibitors, while revolutionising cancer treatment, have been linked to immune-related adverse events affecting the myocardium, pericardium, and conduction system, albeit less frequently.⁹ Radiation therapy to the chest, particularly for breast cancer or lymphoma, can lead to accelerated atherosclerosis, valvular heart disease, pericardial disease, and myocardial fibrosis, often with a latency period of several years.¹⁰

The impact of cardiovascular disease on cancer patients is also substantial. Patients with pre-existing CVD may be less tolerant of aggressive cancer treatments, potentially leading to dose reductions or treatment interruptions, which could compromise oncological outcomes.¹¹ Furthermore, cardiovascular events, such as myocardial infarction or stroke, can occur during cancer treatment or in survivorship, contributing to non-cancer mortality.¹² A study published in 2023 found that patients with a history of heart failure had a 2.5-fold (95% CI 2.1-3.0) increased risk of developing certain solid tumours compared to those without heart failure, with a p-value of <0.001.¹³ This highlights the need for vigilant cardiovascular risk management in cancer patients and survivors.

Managing patients with both conditions requires a multidisciplinary approach involving oncologists, cardiologists, and primary care physicians. Pre-treatment cardiovascular risk assessment is essential to identify patients at high risk of cardiotoxicity.¹⁴ This may involve baseline echocardiography, electrocardiography, and biomarker assessment. During cancer treatment, regular cardiovascular monitoring is recommended, with specific protocols varying based on the cardiotoxic potential of the therapy.¹⁵ Post-treatment, long-term surveillance for cardiovascular complications is critical, especially for survivors of childhood cancers or those who received highly cardiotoxic regimens.¹⁶ Lifestyle modifications, including diet, exercise, and smoking cessation, remain cornerstones of both cancer and cardiovascular disease prevention and management.¹⁷