What Causes Pain In Breast?

Hi, I would like to ask about Bilateral fibroAdenosis? My wife is 32 years and she is suffering from a pain in the right breast and the doctor told her that you have this disease and we do not know exactly what is this disease? we are afraid from this thing? we are thinking that its a cancer but benignant one! so Please doctor tell me what is this disease and its a cancer or not?Thanks in advance I am waiting for your reply my email is I am from Palestine