Over the last two to three decades there’s been a dramatic improvement in cancer treatment. More and more people are surviving the disease. More people are surviving for longer after a diagnosis, with 57 per cent of patients surviving ten years or more.
While this is without doubt a cause of for celebration, the consequence of this is we’re now seeing many more people with heart problems related to their cancer treatments.
So one area of real success in the NHS has led to the need for a completely new service, and seven years ago I, along with colleagues at Royal Brompton and The Royal Marsden hospitals, set up the UK’s first cardio-oncology clinic. We have since treated 900 patients.
Do cancer drugs cause heart problems?
New targeted or ‘designer’ cancer drugs are highly effective at treating cancers. However, we now understand the biology of cancer and the heart muscle do in fact have lots of similar properties: in other words, what is causing growth in the cancer may be important for survival in the heart muscle.
Drugs that inhibit these molecular pathways in effect drive away cancer, but may be damaging the heart. Herceptin, for example, is a fantastic drug for treating cancer, but some patients need additional support, for example those with pre-existing cardiac conditions.
As treatment for cancer has improved, unsurprisingly, in the last decade we’ve had an explosion of heart problems caused by modern cancer drugs.
My first question to the oncologist, when I have a patient who’s having problems is, “Is the cancer responding to the medication the patient is on?’ Because if it is, we will move mountains to try and support their heart, so they can continue the drug.
Research shows that chemotherapies tend to cause damage to the heart, but this may be reversible, if we pick it up early. With the more modern cancer drugs the issues are a bit more complicated — with imaging, we’re seeing less damage but lots of functional problems; that is to say the heart can get very weak very quickly as a result of the cancer treatment, but we can usually rescue it back to normal equally quickly with appropriate medication.
What are the risk factors for cardiac issues?
For patients, risk depends on what their pre-existing heart health is like, if they smoke or have diabetes or hypertension. Occasionally, people who are very fit and healthy still get problems with the cancer treatments.
It could be a one in 20 risk or it could be a one in five risk of developing heart problems during their cancer treatment. Not everybody will have heart problems but our view is that we should be monitoring the heart during the period when people are having treatment so if we can pick up a problem early then we can use modern cardiology care to intervene and support the heart so that they get the best cancer treatment safely.
Has this altered the way we approach patients’ care? We work with our colleagues in cancer care to optimise patients’ cardiovascular systems before we start our treatment. That has been a real shift in my opinion.
It’s also important to keep the risk factors in perspective. Perhaps between one and three people in a hundred may have some kind of significant issue.
How we can help cancer patients avoid heart problems
There are things we can do to help avoid patients having treatment-related heart problems. We don’t know when someone’s going to have a heart attack; however we will know when they’re going to be given chemotherapy or a prescription for a tablet that has a risk of exacerbating cardiac problems.
We can use closer monitoring with modern technology imaging, such as heart scans and blood tests for measuring any possible injury to the heart, very early on. If the results are normal, we can be reassured that the patient is having their cancer treatment safely, if we pick up early signs that the heart’s under strain, we then make sure the patient has the appropriate heart medicines to support their heart throughout their treatment for cancer.
By working with specialist cancer units such as The Royal Marsden Hospital, I feel confident we can continue to offer patients even better outcomes.