Modern treatment strategies have led to improvement in the chances of surviving a diagnosis of cancer; the five-year survival for early stage breast cancer increased  from 79 percent in 1990 to 88 percent in 2012 and similar improvements have been seen with other cancers including non-Hodgkins lymphoma and testicular cancer. Modern cancer treatments however can come at a cost. 

Cardiotoxicity, a relatively new term in the medical literature, refers to the impact of cancer therapies on the heart and cardiovascular system. Cardiac complications from cancer treatments can result from multiple factors including: pre-existing patient factors (e.g high blood pressure), cancer-related factors, and toxic effects of the chemotherapy drugs.

Cardiotoxic manifestations of cancer therapy include left ventricular dysfunction (decrease in cardiac contractile function) and heart failure (clinical syndrome resulting from the inability of the heart to supply sufficient blood flow to meet the body’s needs), myocardial ischemia, infarction, hypertension, and bradycardia (low heart rate). 

A new branch of medicine

Cardiotoxicity is now recognized as a leading cause of long-term morbidity and is the second leading cause of death among cancer survivors. The increasing awareness by healthcare providers of the potential negative impact of cancer treatments on cardiovascular health has resulted in the development of a new branch of medicine – Cardio-oncology.

“Cardiotoxicity is now recognized as a leading cause of long-term morbidity and is the second leading cause of death among cancer survivors.”

Cardio-oncology is a multidisciplinary approach, involving oncologists, cardiologists, pharmacists, nurses and other allied health care providers, developed to provide patients with the best cancer treatments available without negatively impacting cardiac health. For patients “at risk” or with a history of heart disease, oncologists and cardiologists work together to develop strategies to avoid or minimize cardiac complications related to cancer treatment.  

A collaborative approach

Our population is aging: many Canadians will face a diagnosis of heart disease, cancer or both.  Working together we can strive to provide individuals with “state of the art” cancer therapy while optimizing cardiac health – the cured cancer patient of today does not want to become the heart failure patient of tomorrow.

This integrated multidisciplinary approach, has resulted in the establishment of several cardio-oncology programs in Canada, the United States, Europe and South America. 

While our understanding of how modern cancer therapies impact the heart continues to evolve, many knowledge gaps persist: how can we predict who will develop cardiotoxicity, what is the best prevention strategy, how should we monitor those at risk of cardiotoxicity and what are the best management strategies? There is an urgent need for collaborative studies to address these questions.

Organizations such as the Canadian Cardiovascular Society (CCS), Canadian Cardiac Oncology Network and the International Cardiooncology Society, will play an important role in the promotion of clinical care models, development of educational programs (for patients and healthcare providers) and facilitation and promotion of evidence-based research.