As cancer therapies improve and increasingly achieve cures or recurring periods of remission, preventing and managing damage to organs from cancer treatment has become a top concern.

That includes injury to the heart, says cardiologist Dr Joerg Herrmann, who founded and is the director of Mayo Clinic's Cardio-Oncology Clinic in Minnesota, United States.

As physicians and researchers work to prevent, diagnose and treat heart damage from cancer therapies, they also have learned about connections between cancer and the heart that go beyond the cardiac effects of cancer treatments.

Dr Herrmann shares three things to know:

Cancer and heart disease have common risk factors, Dr Herrmann says.

Those include lifestyle habits.

"We call it the web of risk factors.

"Some of the very same lifestyle-related factors can set patients up for both cancer and cardiovascular [heart] disease," he explains.

"Smoking is a prime example.

"It increases the risk of lung and other cancers, and coronary artery disease, heart attacks and peripheral artery disease."

In addition to not smoking, you can reduce your risk of cancer and of heart disease by achieving a healthy weight; avoiding or moderating alcohol use; controlling cholesterol (some cancer treatments can worsen cholesterol levels); getting enough sleep; and adopting a healthy diet with fruit and vegetables, he adds.

Physical activity is another important factor.

It has been shown to reduce heart damage risk during cancer treatment, help prevent cancer recurrence and improve cardiovascular outcomes, he says.

"The more elements of a healthy lifestyle you meet, the better your health projection is for the heart and cancer," Dr Herrmann says.

"You will reduce the risks of two of the leading killers and increase life expectancy."

Cancer and heart disease can actually be risk factors for each other.

"We've realised that the relationship between cancer and heart disease works in both directions," he says.

"Cancer itself can impact the cardiovascular system, apart from cancer therapies, and vice versa.

"Patients with heart failure or other cardiovascular diseases have a higher risk of cancer."

Which treatments are given and how can affect the risk of heart damage, Dr Herrmann says.

For example, the medical team may:

• Use treatments that minimise harm to healthy tissue, such as targeted therapies or proton beam therapy.
• Stagger certain chemotherapy drugs to give the heart a chance to heal between treatments.
• Use medications that protect the heart during chemotherapy.
• Use techniques to shield healthy tissue during radiation therapy, such as body positioning and breath-holding to provide greater separation between the tumour and the heart. 

   

  "These shielding efforts have come a long way for adults and children who have cancer," Dr Hermann comments.

The goals of Dr Herrmann's research include developing tools that predict – before treatment – who is at high risk of heart damage from certain cancer therapies.

This would enable shared decision-making among patients and their care teams about the approach to treatment.

He and his colleagues are also working on therapies to mend hearts "broken" by chemotherapy, and to develop easier and more cost-effective surveillance strategies for cardiovascular side effects of cancer therapies.

Early detection and intervention are likely to lead to the best outcomes, he says.

The use of wearables and artificial intelligence (AI) can help, he adds.

Research has found, for example, that applying AI to an electrocardiogram (ECG), a test that measures the heart's electrical activity, may help detect a decline in heart function.

"We're interested in going further with AI technologies and developing simulations to show how different therapies would affect a given patient," he says.

Some patients remain at risk of heart disease for a lifetime after cancer treatment, but it's impractical to do echocardiograms to look at the heart for the rest of their lives.

Wearables to alert cancer survivors and their care teams to cardiac abnormalities are another promising area of research, he says.

"We've come a long way in cardio-oncology.

"We have a much better understanding of what we can do to manage heart risk from cancer therapies," Dr Herrmann says.

"Patients are in much better place now than they were even 10 years ago."