Chemotherapy and radiotherapy do not harm the heart of breast cancer patients in the long term, according to a study by the German Cancer Research Center.
Breast cancer is the second most common cancer worldwide and the most common in women. The disease is, if it is diagnosed in time, usually curable. “However, some clinical studies have suggested that both chemotherapy and radiotherapy are associated with the risk of suffering from heart disease as a result of treatment,” says Hermann Brenner from the German Cancer Research Center. Still, little was known about the actual risks of these side-effect heart diseases.
Data from American patients evaluated in a recent study from the German Cancer Research Center have now helped to dispel this concern. Brenner’s team has evaluated the data of approximately 350,000 patients from US cancer registries. The women had breast cancer between 2000 and 2011 and were then treated with radiotherapy or chemotherapy. The scientists compared the data of the women with data on the average female population in the United States and came to the clear conclusion: the risk of dying of heart disease in the long term, after breast cancer treatment is no greater than in the average female population. This applies to chemotherapy as well as to radiation.
Also, special treatments for the subgroup of so-called HER2-positive patients are not associated with a higher risk of death from heart disease. “We were surprised by this result at first,” says Janick Weberpals, lead author of the study. “But we expect our study to give a more realistic picture of the actual situation of the treatment than is the case in clinical trials.” For clinical studies, groups of volunteers are put together according to specific criteria. However, the evaluation of cancer registries takes into account all breast cancer patients included in it.
In part, the effect can probably be attributed to good risk management in the clinics, for example through special cardio-oncological units. The individual risk of a patient to suffer from heart disease due to breast cancer treatment is already taken into account in the selection of the appropriate therapy. Close monitoring during the course of treatment also makes it possible to detect side effects on the heart at an early stage, to adjust the oncological therapy accordingly and to treat a possible heart disease quickly.
“We regard the result of our study as very positive for the treatment of breast cancer,” summarizes Brenner. It shows that the benefit-risk balance is right for most patients. “In particular, it is very good news for the large number of affected patients that they no longer have to worry about deadly heart disease in good medical care and after surviving breast cancer, like women of the same age without breast cancer.”