There are significant risks associated with irradiating the breasts, including the development of other forms of cancer, heart disease, and fibrosis of the lungs.
In fact, studies have found a significantly higher risk of major cardiac events for women who have undergone radiation for breast cancer on the left side of the chest (where the heart is located.)
Women should be very concerned about that, because heart disease is the number one killer among them.
I have seen many women who develop severe cases of heart disease years later after having their left breast irradiated.
The heart effects of breast irradiation can begin emerging as soon as five years after treatment.