Hello,I am about to turn 61, and I had my mastectomy 2 years ago.Like you,the difference between Tamoxifen and no Tamoxifen,is small,but as my oncologist said,' it could be the difference'.I have ADVANCED osteoporosis,and that is the reason I stay on tamoxifen,and don't go onto an aromatase inhibitor medication.Tamoxifen actually helps strengthen bones in POST MENOPAUSAL women.As for side effects,the only ones I ever had were increased hot flushes ,in the beginning.Now,2 years down the track I feel absolutely fantastic.Please feel free to ask more questions if I haven't covered everything.Cheers Robyn.xox