Because some of the newest biologic and targeted cancer therapies can cause cardiac toxicity as much as older chemotherapeutic agents, many cancer patients may be at greater risk for death from treatment-related cardiac toxicity than relapsing or chronic cancer, according to an article in the June 29th issue of Circulation.

Cardiologists at The University of Texas M. D. Anderson Cancer Center reviewed 30 years of clinical experience as well as current research to write the first large-scale review detailing cardiovascular complications that often occur in cancer therapy, as well as ways to prevent or treat them.

According to the study’s lead author, Edward T. H. Yeh, MD, the findings are particularly important because both patients and doctors may not be aware of the spectrum of heart problems that can arise from cancer treatment, or know that many of these problems can be managed.

“Many cancer survivors will actually be at greater risk from cardiac disease as from recurrent cancer,” said Yeh. “Now that cancer is often being treated as a chronic, manageable disease, it is critical that this treatment doesn’t substantially weaken a patient’s heart.”

In fact, the research team found in their review of 29 anticancer agents that there is no class of cancer drug that is free of potential damage to the heart, the organ that seems to be most sensitive to toxic effects of anticancer agents.

Generally speaking, patients at most risk for cardiotoxicity are those who are aged and have other illnesses, such as diabetes or existing heart disease. However, cardiotoxicity can occur in any patient, either during treatment or months or years after treatment.

Even the newest targeted therapies, designed to attack only cancer cells, can cause cardiotoxicity, Yeh said. For example, monoclonal antibody drugs such as Avastin, Erbitux, and Rituxin produce a significant amount of hypertension as well as hypotension in patients. “They seem to have more general toxicity than many other agents, but the problems they produce usually involve changes in blood pressure, which can be easily treated if recognized,” Yeh noted.

Agents such as the anthracyclines and anthraquinolones are clearly more dangerous and require close monitoring because they can cause irreversible chronic heart failure or left ventricular dysfunction, especially in large doses. Even with these agents, the authors noted, cardiotoxicity can be limited. Alkylating agents and antimetabolites can produce ischemia, and potentially myocardial infarctions.

Non-chemotherapy drugs noted for their high risk of cardiotoxicity include Interleukin-2, which frequently results in hypotension or arrhythmias; Gleevec, which can cause heart failure; Trisenox, from which fatal “QT prolongation” can result; and Thalidomide, which can produce a variety of serious heart ailments.

On the other hand, the researchers found that Herceptin is less toxic than generally believed, although it can cause chronic heart failure and left ventricular dysfunction.

“We found a profile of cardiotoxicity for the most often used anticancer drugs, but it is important to know that every patient has different risk factors that will determine how their hearts handle the treatment,” concluded Yeh. “Monitoring and management is key to surviving cancer with a good and lasting heart.”