I had my first mastectomy 2005 and then a (bilateral) within 10mths. Since then I have had a constant cough ( white stringy phlegm) which has gradually got worse and I do have difficulty breathing ( very concerned). I did blame this on Tomifen I am now on Arimidex for the last month! I was a very fit,healthy, drug free person before 2005. Could this problem be due to Tomoxifen? I would appreciate a logical answer rather than being prescribed by my GP ------- simple linctus!!!