Current Developments in Serum Biomarkers for Cardio-oncology Risk Stratification and Patient Management

Cardio-oncology is at the intersection of cardiology and oncology, focusing on an emerging dual mandate of optimizing outcomes in cancer therapies and minimizing associated cardiovascular toxicity. The cardiovascular consequences of cancer treatment include anthracyclines, trastuzumab, and checkpoint inhibitors, covering the spectrum of asymptomatic myocardial injury through overt heart failure and arrhythmias. These complications have a great impact on the quality of life and survival of cancer patients, and thus, early identification and proactive management are necessary. Robust serum biomarkers have become indispensable tools for risk stratification, early diagnosis, and therapeutic monitoring, providing a non-invasive and cost-effective approach to patient management. Traditional biomarkers, such as cardiac troponins and natriuretic peptides, remain the mainstay for detecting myocardial injury and cardiac dysfunction. Troponins are very sensitive and specific markers of acute and cumulative cardiotoxic effects of therapies. Natriuretic peptides, including B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP), are important for the diagnosis and monitoring of heart failure. However, these biomarkers are often unable to detect subclinical cardiotoxicity or to fully capture the complex pathophysiological mechanisms underlying cancer therapy-induced cardiac injury. In doing so, emergent biomarkers have expanded the horizon of cardio-oncology beyond the earlier simplistic diagnostic and prognostic limitations. Galectin-3 and soluble ST2, with their potential roles in fibrosis and myocardial stress, indicate early stages of cardiac remodeling. GDF-15, one of the related inflammation biomarkers, has become more useful in its ability to forecast adverse cardiovascular consequences in cancer patients undergoing cardiotoxic treatments. In addition, circulating microRNAs (miRNAs), small noncoding RNAs, have emerged as highly specific and sensitive indicators of myocardial stress and injury. Among these, miR-126, miR-208, and miR-34a are notably interesting as they play roles in detecting subclinical cardiotoxicity and provide insight into disease progression. Advances in proteomics, metabolomics, and multi-biomarker panel technologies have further helped to enhance serum biomarkers. High-throughput omics platforms also help in the discovery of previously uncharacterized biomarkers and clarify the molecular mechanisms of cardiotoxicity.