Tamoxifen better for 10 years?

I have been on tamoxifen for about 20 months and have had very minimal if any side effects from it.  I was 46 when I had chemo, had one period between finishing chemo and starting tamoxifen and none since then so am menopausal now (don't really know if that's caused by chemo or  tamoxifen or combination of both.)

I had mild hot flushes several times a day to start with but they barely trouble me now. Only very occasional. And I do sometimes wake up at 5am too but I used to do that before my BC diagnosis so may not be related. I guess my libido has dropped off a bit too, sadly, but I put that down to menopause itself rather than tamoxifen. 

I suspect the key thing to avoiding/minimising side effects in my case is exercise. I ususally do an aerobics or weight class or a run at least 5 times a week. It can be a drag sometimes but it does make me feel good, it reduces the risk of recurrance and it has helped me avoid gaining any weight. 

My oncologist wanted to swap me to an aromatase inhibitor once it became clear I was definitely menopausal but I hate the sound of the side effects they cause so I opted to stay on tamoxifen. She didn't seem to think it mattered much.  At this stage she has only suggested taking hormone suppressing drugs for 5 years. Wouldn't want to take it for 10 unless absolutely necessary. I do worrry sometimes about the risk of uterine/endometrial cancers. Good luck , Janet.