A link has been established between radiation for breast cancer and heart problems later in life.  Doctors in Oxford, England have found the risk comes from any amount of radiation, starting five years after treatment and lasting for decades.  Lead author Sarah Darby says women who’ve received radiation for breast cancer shouldn’t worry.  She says, “the most important thing is for most women, they now have evidence to reassure them, and for most doctors too, to reassure them that the benefits of radiotherapy will outweigh the risks, in terms of heart disease.”  Also she says,  the chance of suffering a radiation-induced heart problem is fairly small.