Therapy-naïve malignancy causes cardiovascular disease: A state-of-the-art cardio-oncology perspective

Cardiovascular disease (CVD) and cancer are the leading causes of mortality worldwide. Although generally thought of as distinct diseases, the intersectional overlap between CVD and cancer is increasingly evident in both causal and mechanistic relationships. The field of cardio-oncology is largely focused on cardiotoxic effects of cancer therapies (e.g., chemotherapy, radiation). Further, the cumulative effects of cardiotoxic therapy exposure and the prevalence of CVD risk factors in cancer patients leads to long-term morbidity and poor quality of life in this patient population-even when patients are cancer-free. Evidence from cancer patients and animal models demonstrates that the presence of malignancy itself, independent of cardiotoxic therapy exposure or CVD risk factors, negatively impacts cardiac structure and function. As such, the primary focus of this review is the cardiac pathophysiologic and molecular features of therapy-naïve cancer. We also summarize the strengths and limitations of preclinical cancer models for cardio-oncology research and discuss therapeutic strategies that have been tested experimentally for the treatment of cancer-induced cardiac atrophy and dysfunction. Finally, we explore an adjacent area of interest, called 'reverse cardio-oncology', where the sequelae of heart failure augment cancer progression. Here, we emphasize the cross-disease communication between malignancy and the injured heart, and discuss the importance of chronic low-grade inflammation and endocrine factors in the progression of both diseases.