http://www.news-medical.net/?id=36100
Keep in mind, though:
"The research team notes that this study is limited by the fact that participants choose whether to take the drug themselves and were not randomly assigned. While a randomized clinical trial would more conclusively determine the benefit of letrozole treatment for those who have been off tamoxifen for several months or years - or even those who never took the drug - the results of this study can help guide physicians and patients in deciding whether letrozole therapy would be appropriate."