Have taken Tamoxifen and having reoccurring ADH & ALH

I was diagnosed with LCIS over 10 years ago (a step further along the bc spectrum; a stage 0,  in-situ, non-invasive bc) and took tamoxifen for 5 years (I still take evista for further prevention). My understanding of the purpose of tamoxifen is to help prevent invasive bc;  I don't think it actually does much to prevent the pre-cancers themselves (ADH and ALH) or the in-situ non-invasive cancers (LCIS and DCIS), but I could be wrong. My main objective in taking preventative meds (tamox or evista) is to avoid anything invasive. Most of the literature says that the tamox has benefits that extend 5-10 years beyond when you finish taking it for 5 years. (so taking the evista may be overkill, but all my docs feel it's a good idea, so I stay on it for now.

Anne 

Kathy, my understanding is the same as Anne's, which is that the purpose of Tamoxifen is to prevent ADH from developing further to become invasive cancer.  I don't know that Tamoxifen prevents the development of ADH itself.  

It is also my understanding that 5 years of Tamoxifen is generally thought to work for about 10 years, although with less benefit over the last few years. The ATLAS study released last year showed that 10 years of Tamoxifen is more effective at reducing breast cancer recurrence risk than 5 years of Tamoxifen.  This is because the benefit of 5 years of Tamoxifen was pretty much gone after 10 years, whereas those who took Tamoxifen for 10 years continued to have benefit up to year 15 (which was as far as the study had gone at that time). This study was not done on high risk patients - it measured recurrence risk and mortality rates for those who already had been diagnosed with breast cancer - but I would bet that the results would be similar when it comes to breast cancer risk reduction.  

So if you took Tamoxifen for 5 years starting in 2001, my guess is that you most likely are not getting any further risk reduction benefit from it at this time.  Probably not what you want to hear.