Women who were treated with radiation for breast cancer during the 1980s may be at an increased risk for heart disease compared with the general population, according to a new study in the March 7 Journal of the National Cancer Institute. Despite this increased risk of heart disease, radiation therapy has been previously shown to improve the chances of surviving breast cancer.
Breast cancer patients treated with radiation therapy during the 1970s are thought to have an increased risk of cardiovascular disease, but those treatment procedures are now considered obsolete. However, studies on the association between more modern radiation therapies and cardiovascular disease in breast cancer survivors have been inconclusive.
Maartje Hooning, M.D., of the Netherlands Cancer Institute in Amsterdam, and colleagues compared radiation treatment options, looking for differences in heart disease incidence among 4,414 10-year survivors of breast cancer who were treated between 1970 and 1986. Approximately half of the patients were treated for breast cancer between 1970 and 1980 and half were treated after 1980.
After a median follow-up of 18 years, the researchers identified 942 cases of cardiovascular disease, heart failure being the most common (382 out of 942). The breast cancer patients had an increase in the risk of heart attack, angina (chest pain due to an oxygen shortage in the heart), and congestive heart failure, compared with the general female population. The incidence of angina seemed to increase over time.
The researchers found differences in cardiovascular disease incidence depending on the type of treatment. Overall, patients who received radiation therapy had a greater risk of cardiovascular disease compared with those who received only surgery. In fact, the women who received only surgical treatment had a lower risk of heart attack than the general female population.