Letrozole or Tamoxifin?

Think positive - may not seem much of a choice, but much better than cancer! I took the letrozole road, but .... I was almost a decade older than you when I started, had excellent bone density and I did a full ten years on letrozole. My bone density now is not great, but then again it's pretty par for my age group. The impact was not so developed after five years but my oncologist felt that, in my case, research warranted a further five years. I didn't go the bone strengthening route (prolia or similar). I was anxious about teeth - being older, and with some dental work looming, but many have. You can of course have dental treatment but it needs to be between courses of the drug. Which may not always be the best option. Also the drug is more or less ongoing, if you stop taking it, your bone density drops. None of this may present problems in your case. 

Another side effect of letrozole can be joint pain - I never had a twinge, but many others have stopped taking letrozole because of severe joint pain. I'd ask your oncologist if you can switch from letrozole to tamoxifen if you experience really bad side effects. To my limited knowledge (I have never taken tamoxifen), it's usually not the preference for post-menopausal women. But your oncologist is doing all the right things by providing lots of material and giving you time to decide. And what happens to one person, even in what seems very similar circumstances, isn't what happens to another. The major thing to remember is that the treatment is to keep cancer at bay - 14 years post diagnosis and I am NED (no evidence of disease). Good luck whatever you decide.