Speakers will call for greater interdisciplinary practices between cardiologists and oncologists which consider the patient's individual risk profile. The cardiovascular side effects of anticancer agents are important, they say, because they result in systolic and diastolic dysfunction, and progressive cardiac disease. This can significantly impair the long-term prognosis of cancer survivors.
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Untreated cardiomyocyte: one cardiac
muscle cell (cardiomyocyte) isolated from
an adult rat heart and cultured for ten days
Photo: Dr Christian Zuppinger
University Hospital, Bern
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“More and more we're seeing paediatric cancer survivors who are now in their 30s and 40s and whose only option is a heart transplant,” says Federico Quaini, an oncologist from Parma, Italy. Estimates suggest that around 10% of surviving cancer patients develop cardiac dysfunction, which often takes 10-20 years to manifest itself after treatment.
“Oncologists need to identify the patients who are likely to have trouble, and know exactly when to alert the cardiologists to prevent damage,” says Thomas Suter, a cardiologist from the Swiss Cardiovascular Centre in Bern. “The problem, particularly with the older drugs, is that once damage has occurred it can't be reversed.”
The Symposium will review how the type of damage differs between the old anticancer agents, such as anthracyclines, and the newer targeted therapies. Anthracyclines – used for over 30 years to treat breast and ovarian cancer, sarcoma and lymphoma – cause cell death, and are unable to distinguish between cancer cells and cardiac myocytes.
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Cardiomyocytes treated cardiomyocytes: a group
of cardiomyocytes cultured in the same way as
the untreated ones but treated for two days with
doxorubicin, a classic cancer chemotherapy
known for its toxic effect on the heart
depending on the cummulative dose.
Photo: Dr Christian Zuppinger
University Hospital, Bern
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Targeted therapies - like trastuzumab, imatinib, sunitinib and sorafenib - are thought to damage the contractile apparatus of cardiac myocytes, although microfilaments may reassemble with time, reversing the damage. A recent study of sunitinib or sorafenib in renal cell cancer indicates that 33.8% of patients suffered a cardiac event.
Before starting any treatment Quaini believes that cancer patients, regardless of age, should have an assessment of their cardiovascular risk factors, including BMI, cholesterol, blood pressure, coagulation, carotid artery thickness and endothelial function. If risk factors are found, patients can be offered supportive therapy (such as ACE inhibitors, beta-blockers and statins to prevent the damage from occurring in the first place), or be prescribed special formulations of anthracyclines packaged with liposomes or nitric oxide to protect the heart. “We're currently conducting studies to determine whether drugs able to preserve cardiac repair machinery, given five days before treatment, have cardioprotective effects in children,” says Quaini.
During treatment and beyond, says Suter, regular screening is important to detect any ongoing damage - to differentiate between transient reversible cardiac dysfunction (as seen with targeted treatments) and the non-reversible cardiac damage found with anthracyclines. “My recommendation is to perform routine echocardiograms," he adds. "If any problems are identified you need to test for biomarkers. If raised, they indicate that patients are losing myocardium and need preventative action.”
In future, Suter hopes that gene profiling will be available to identify those patients at greatest risk of developing cardiac problems. Untreated