No one wants to be cured of cancer just to die of a heart attack. Unfortunately, many of the chemotherapy agents used to treat cancer have damaging effects on the heart. Physicians must carefully balance the risks and benefits of these powerful drugs.
Dr. Manabu Minami of Kyoto University Hospital, Japan, provided a review of cardiovascular side effects of cancer drugs. “Over the past few decades, cancer treatment has dramatically evolved,” Minami wrote.
Advances in the number and effectiveness of chemotherapy agents offer better results in treating cancer. However, some of the newer molecular target drugs are comparable to the well-known anthracyclines in terms of cardiotoxicity.
Heart disease can develop at any time after chemotherapy, even decades later. Children treated for cancer have a 15.1-fold increased risk of congestive heart disease, a 10.4-fold greater risk of coronary artery disease, and a 9.3-fold greater risk of cerebrovascular events, such as stroke, compared to their siblings who did not have childhood cancer. The risk of cardiovascular disease for these long-term survivors is greater than their risk for a second cancer.
The overall risk of cancer increases with age, so most patients who receive chemotherapy are also at risk for cardiovascular disease. Women have higher rates than men of cardiac toxicity from the well-known anthracyclines. Other risk factors include high blood pressure, heart conditions prior to cancer therapy, radiation therapy to the chest, use of multiple cancer drugs, and cumulative dose.
Minami described the following cytotoxic drugs to have significant cardiac toxicity:
1.Anthracyclines
2.Taxanes (paclitaxel and docetaxel)
3.Flurorpyrimidine (5-FU)
4.Cyclophosphamide
5.Cisplatin
For molecular target drugs, also called targeted chemotherapy, Minami reported cardiac toxicity issues for the following:
1.Trastuzumab
2.Cetuximab
3.Lapatinib
4.Bevacizumab
5.Sunitinib
6.Sorafenib
7.Imatinib
8.Rituximab
Dr. Aarif Y. Khakoo of The University of Texas M. D. Anderson Cancer Center in Houston, Texas, and colleagues presented a report on the mechanisms of cardiotoxicity at the First International Conference on Cancer and the Heart in November 2010. These authors explained that the heart has significant intrinsic repair mechanisms, which are interrupted by chemotherapy agents.
Research is in progress to understand exactly what happens. “Such studies have the potential to develop strategies that will prevent cardiac toxicity from becoming a barrier to effective anti-cancer therapy,” Khakoo wrote. “They might also provide novel insights into the pathogenesis of non-cancer-therapy-induced human heart disease.”
References:
1. Minami M et al, “Cardiovascular side-effects of modern cancer therapy”, Circulation Journal 2010; 74: 1779-86. http://www.ncbi.nlm.nih.gov/pubmed/20716834
2. Khakoo AY et al, “Cardiotoxicity due to cancer therapy”, Texas Heart Institute Journal 2011; 38(3): 253-6.
http://www.ncbi.nlm.nih.gov/pubmed/21720463
Linda Fugate is a scientist and writer in Austin, Texas. She has a Ph.D. in Physics and an M.S. in Macromolecular Science and Engineering. Her background includes academic and industrial research in materials science. She currently writes song lyrics and health articles.
Reviewed November 28, 2011
by Michele Blacksberg RN
Edited by Jody Smith