CANCER CHEMOTHERAPY AND CARDIOTOXICITY

Cancers are rapidly catching up with heart disease as the number killer in USA. In Canada, it has already overtaken heart disease as the number one killer, and in Malaysia, it is increasing in importance, but has not yet overtaken heart disease as the number one killer. Nonetheless, we are seeing more and more cancers being diagnosed and undergoing treatment. These treatments are expensive and full of side-effects. This is not surprising as the drugs are meant to damaged and kill malignant cells and will surely also inadvertently kill or damage normal cells especially those cells that are the most rapidly dividing.
Undoubtedly, these agents also can harm cardiac cells, and here, should it occur, may impair heart function and also cause heart failure and death. Cardiologist are often called to evaluate heart function sometimes before the start of chemotherapy and often after chemotherapy has been started, and there were some problems.
Two papers give us a look into the effects of cancer chemotherapy and the heart. Both papers were presented at the ongoing EUROECHO 2011 at Budapest.
The first paper presented, by Dr Helder Dores of Lisbon, Portugal, studied the effects of Trastuzumab or Herceptin on the heart. Herceptin ( as it is commonly known ), is a very effective chemotherapy for Ca Breast. She studied 51 patients with echocardiography, before and 3 months after trreatment. She found that before symptoms of heart failure and LV systolic functions get impaired, the LV diastolic functions become impaired. This happens in almost 20% of patients, and does not seem to be dose related.
The second paper, by Dr Liliana Radulescu of Romania, studied the effects of Epirubicin on malignant tumours of various kinds. She did echocardiograms in all the patients, the 31 who had the chemo only and the 26 patients who had the chemo and also were given lisinopril 10mg and rosuvastatin 10 mg. She found that those patients ( 31 pts ) who only had chemo showed deterioration in LV diastolic function, but those who received chemo and also lisinopril / rosuvastatin, seemed protected from the deterioration in LV diastolic function, showing us that the adverse effects of the chemotherapy ( in this case, Epirubicin ) on the heart, can be prevented.
Obviously, these numbers are small, and should provide a direction for future larger scale studies. They however serves as important early work in an area that will become more and more important.
It may be good for us to take a few lines to review the effects of cancer chemotherapy on the heart. It is wellknown that most of the anthracyclines ( a group of chemotherapy agents commonly used ) will have some form of cardio-toxicity. These may range from LV diastolic dysfunction, to LV systolic dysfunction and heart failure. They may also cause, arrhythmias, hypertension, and also thromboembolism and heart attacks. They can damage plagues and cause them to rupture. It is good medical practice to do an ECG and echocardiogram as baseline before the start of therapy ( especially if anthracyclines are to be used ) so that we can appreciate the deterioration of LV diastolic function, should it occur and prevent the occurrence of LV systolic dysfunction. These chemotherapy cardiac effects may occur immediately upon treatment, or they may be delayed, showing up only years after therapy. And they may not be dose related.
Obviously, there is still much that we need to learn about cancer chemotherapy and the heart, and I am sure, with the rapid increase incidence of cancers, this area of medicine will get more research funds and more work will surely be done.
This will be good for our patients with cancers.