Tamoxifen as a preventative measure?

great news on the benign results!  None of the conditions you mentioned put you at high risk. They all only increase your risk slightly. Are you sure they said "typical" hyperplasia or was it "atypical"? The atypical (ADH) is what would increase your risk to  20-25%. (and a recommendation for the tamoxifen)

Tamoxifen does not cause you to lose bone, it actually is very good for your bones. It does not put you into menopause (although some of the SEs are similar to menopausal symptoms) and the risk of uterine cancer is very low, <1%.  I took it preventatively for 5 years and tolerated it well, I would just recommend a yearly transvaginal US to monitor both the uterine lining and the ovaries.

anne

I have classic LCIS, ALH, and a weak family history. (Paternal grandmother, 2 maternal aunts (all post-menopausal), 2 maternal cousins, one pre- and one post-menopausal.)  I have gotten estimates of my lifetime chance of bc as anywhere between 10 and 40%.  I think in the long run, they really, really don't know how to estimate one's future risk of bc. nci.oxfordjournals.org/content/98/23/1673.full.pdf

Since my breast surgeon refused to do PBMs on me (Her first words to me were 'If you want PBMs, I will fall over in a chair')and I had no other breast surgeons that took my insurance, I chose tamoxifen and took it for 5 years.  I had benign endometrial polyps every 1.5 years, but I also had endometrial polyps (all benign) before starting tamoxifen.  It caused some warm flashes at first and these calmed down.    I had 2 more breast biopsies a year after my breast excision for LCIS, but they showed nothing worse than what I had already.  Since then, I have only had annual mammograms and twice-a-year clinical breast exams.   No breast issues since 2007 when I had my 2 benign breast biopsies.

Everyone is different and screening is controversial (at least for LCIS).  Many (not all) people estimate that LCIS confers about twice the lifetime risk as ADH, it is certainly possible  (not certain) that after a period of time your screening intensity will decrease.  LCIS is a different animal than DCIS.

No matter what you choose, you will have friends here that support your choice.

They know the statistics for GROUPS of breast cancer patients, as melissadallas and kayb quoted, but for the INDIVIDUAL PATIENT, that's a totally different story. nci.oxfordjournals.org/content/98/23/1673.full.pdf  estimates the accuracy of the Gail model (the most commonly used model) for an INDIVIDUAL patient as 'better than a coin toss, but not by much'.  (This may not apply if you have a deleterious BRCA mutation or radiation treatment for lymphoma.)  Even when they added factors such as breast density to the Gail model, they found the accuracty was around 60% accuracy (vs 50%-50% for a coin toss). 

The modified Gail model is for GROUPS of fairly normal people - you can imagine the situation for the much smaller population of people with a somewhat higher risk such as people with ADH or ALH - the accuracy must be much closer to 50-50 than 60-40. (In other words, the maximum times they can predict an 'average' individual will or will not get breast cancer correctly is <60% versus 50% of the time for a random coin toss.)

The point being is that though it would be very helpful to make your decision based on 'numbers' - e.g. 'What is my risk for getting breast cancer?', we really do not know that number for YOU.  We know the risk well for groups of fairly normal women (probably including women with ADH and ALH), but not individual women in those groups.

Here's more info about a large study comparing tamoxifen and raloxifene for breast cancer prevention.  As others have said, its about a 50% reduction in risk. This information of course is for groups of women, not individual women. http://www.nsabp.pitt.edu/STAR/Index.asp